WO2018047882A1 - FUNCTIONAL ELEMENT HAVING CELL SERIAL STRUCTURE OF π-TYPE THERMOELECTRIC CONVERSION ELEMENTS, AND METHOD FOR FABRICATING SAME - Google Patents

FUNCTIONAL ELEMENT HAVING CELL SERIAL STRUCTURE OF π-TYPE THERMOELECTRIC CONVERSION ELEMENTS, AND METHOD FOR FABRICATING SAME Download PDF

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WO2018047882A1
WO2018047882A1 PCT/JP2017/032179 JP2017032179W WO2018047882A1 WO 2018047882 A1 WO2018047882 A1 WO 2018047882A1 JP 2017032179 W JP2017032179 W JP 2017032179W WO 2018047882 A1 WO2018047882 A1 WO 2018047882A1
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spun yarn
type
functional element
base material
insulating base
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PCT/JP2017/032179
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French (fr)
Japanese (ja)
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中村　雅一
光洋 伊藤
拓也 小泉
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国立大学法人奈良先端科学技術大学院大学
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Priority to JP2018538450A priority Critical patent/JP6974854B2/en
Publication of WO2018047882A1 publication Critical patent/WO2018047882A1/en

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    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K99/00—Subject matter not provided for in other groups of this subclass
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
    • B32B5/02—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by structural features of a fibrous or filamentary layer
    • D—TEXTILES; PAPER
    • D02—YARNS; MECHANICAL FINISHING OF YARNS OR ROPES; WARPING OR BEAMING
    • D02G—CRIMPING OR CURLING FIBRES, FILAMENTS, THREADS, OR YARNS; YARNS OR THREADS
    • D02G3/00—Yarns or threads, e.g. fancy yarns; Processes or apparatus for the production thereof, not otherwise provided for
    • D02G3/02—Yarns or threads characterised by the material or by the materials from which they are made
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02N—ELECTRIC MACHINES NOT OTHERWISE PROVIDED FOR
    • H02N11/00—Generators or motors not provided for elsewhere; Alleged perpetua mobilia obtained by electric or magnetic means
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N10/00—Thermoelectric devices comprising a junction of dissimilar materials, i.e. devices exhibiting Seebeck or Peltier effects
    • H10N10/01—Manufacture or treatment
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N10/00—Thermoelectric devices comprising a junction of dissimilar materials, i.e. devices exhibiting Seebeck or Peltier effects
    • H10N10/10—Thermoelectric devices comprising a junction of dissimilar materials, i.e. devices exhibiting Seebeck or Peltier effects operating with only the Peltier or Seebeck effects
    • H10N10/17—Thermoelectric devices comprising a junction of dissimilar materials, i.e. devices exhibiting Seebeck or Peltier effects operating with only the Peltier or Seebeck effects characterised by the structure or configuration of the cell or thermocouple forming the device
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N10/00—Thermoelectric devices comprising a junction of dissimilar materials, i.e. devices exhibiting Seebeck or Peltier effects
    • H10N10/80—Constructional details
    • H10N10/85—Thermoelectric active materials
    • H10N10/851—Thermoelectric active materials comprising inorganic compositions
    • H10N10/855—Thermoelectric active materials comprising inorganic compositions comprising compounds containing boron, carbon, oxygen or nitrogen
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N10/00—Thermoelectric devices comprising a junction of dissimilar materials, i.e. devices exhibiting Seebeck or Peltier effects
    • H10N10/80—Constructional details
    • H10N10/85—Thermoelectric active materials
    • H10N10/856—Thermoelectric active materials comprising organic compositions

Definitions

  • the present invention relates to a functional element that can constitute a flexible thermoelectric device and a manufacturing technique thereof.
  • thermoelectric conversion technology that recovers heat and converts it into electrical energy. This is because about 70% of the total amount of energy used around us is exhausted without being utilized.
  • the conventional thermoelectric conversion element with a high unit area price has so far been limited in use because it is difficult to obtain economic merit. Therefore, the use of large area flexible thermoelectric devices that can be used at a low cost for large areas, can be applied to various shapes of surfaces, and is lightweight has the potential to broaden the application. is there. For example, it can be expected to be used as a distributed self-sustained power source in a sensor network used in a smart building or the like, or a power source for driving a small electric device by body temperature.
  • thermoelectric materials have begun to attract attention as promising thermoelectric materials, and their performance has greatly improved with the development of research.
  • many organic materials have been originally developed with the use of electrodes, transistors, and solar cell materials in mind. Therefore, the use with a thin film is common, and it is not easy to obtain a high-quality thermoelectric conversion material having a sufficient thickness necessary for a thermoelectric device.
  • ⁇ is the Seebeck coefficient
  • ⁇ is the conductivity
  • ⁇ is the thermal conductivity
  • T is the absolute temperature.
  • the power factor PF corresponds to the electric power obtained from the thermoelectric conversion material
  • the dimensionless figure of merit ZT corresponds to the energy conversion efficiency. The larger the value of both, the better the performance as the thermoelectric conversion material.
  • the conversion efficiency of the thermoelectric conversion element is ideally determined only by ZT and does not depend on the device structure.
  • thermoelectric material in a steady state with a temperature difference ⁇ T.
  • ⁇ T is not only a material but also a device structure.
  • ⁇ T increases as the thickness increases and the thermal conductivity decreases. That is, the dimensionless figure of merit ZT is a value that does not depend on the device structure, but the output and efficiency of the actual thermoelectric device greatly depend on the device structure. For example, if a device with a thermal conductivity of 0.1 W / mK is attached to an interface with a temperature difference of 15 ° C. with a body temperature of 37 ° C. and an outside air temperature of 22 ° C., A thickness of about 5 mm is required.
  • the thickness is as small as about 200 ⁇ m, the temperature is only about 1 ° C. Since the efficiency and temperature difference of the thermoelectric device have a substantially linear relationship near room temperature, the relationship between the thickness of the thermoelectric device and the thermoelectric efficiency approaches 15 ° C. as the thickness increases, and the thermoelectric efficiency is saturated. . In order to obtain high thermoelectric efficiency, a sufficient film thickness is necessary for the thermoelectric device.
  • thermoelectromotive force generated by the Seebeck effect is proportional to the temperature difference between the low temperature side and the high temperature side of the device, it is important to give a sufficient temperature difference to the device.
  • thermoelectromotive force generated by the Seebeck effect is proportional to the temperature difference between the low temperature side and the high temperature side of the device.
  • the heat flow from the high temperature side is blocked, and there is almost no temperature difference in the thin film shape (several hundred ⁇ m). is there.
  • thermoelectric device for example, see Non-Patent Document 1
  • a temperature difference is made in the thickness direction of the thermoelectric device by stacking thin films (for example, (Refer nonpatent literature 2).
  • Many use the former that is, the method of creating a temperature difference in the in-plane direction, but this method can be used as a distributed power source for medical monitoring and smart buildings that can be considered as a flexible thermoelectric device application. There is a problem that the usage is limited.
  • thermoelectric devices that form woven structures are known.
  • thermocouple-containing fabric that is used as a fabric for heat-resistant protective clothing such as fire-fighting clothing and that can quantitatively measure the environmental temperature (see Patent Document 1).
  • a thermocouple-containing fabric that is, a thermocouple wire is woven between the woven yarns.
  • thermoelectric structure formed by a network of a plurality of wires substantially facing the weft direction (see Patent Document 2).
  • two kinds of metal fibers X and metal fibers Y forming a thermocouple are alternately woven into the warp made of insulating fibers as wefts. As a whole, the wefts are composed of the metal fibers X and the metal fibers Y.
  • line which becomes is known (refer patent document 3).
  • thermoelectric device of Patent Document 1 an electrode has to be formed, and the problem is that the thermoelectric efficiency is greatly reduced because a metal wire is used. Moreover, in the case of the thermoelectric structure of patent document 2, the use as a thermocouple is assumed and since it does not have a pi-type structure, it is a problem that thermoelectric efficiency is bad. Furthermore, the thermoelectric device of Patent Document 1, the thermoelectric structure of Patent Document 2, and the thermoelectric conversion material of Patent Document 3 all have a structure in which the temperature difference is applied in the in-plane direction, and the structure is provided in the thickness direction. Not.
  • thermoelectromotive force is proportional to the temperature difference between the low temperature side and the high temperature side of the device, so it is important to make a sufficient temperature difference between the devices.
  • the thin film shape of about 100 ⁇ m has a problem that there is almost no temperature difference.
  • the present invention provides a structure for obtaining a flexible thermoelectric device having a sufficient thickness for obtaining a temperature difference, and a yarn composed of a thermoelectric material and having sufficient flexibility and mechanical strength is heated. It is an object of the present invention to provide a functional element having a fabric structure sewn on a flexible insulating base material having a low conductivity and a method for manufacturing the functional element. It is another object of the present invention to provide a functional element in which output characteristics are unlikely to deteriorate with respect to disconnection and a manufacturing method thereof.
  • a functional element is used to mean an element capable of exhibiting various functions such as an element for power generation, an element for cooling / heating, and an element for temperature sensing.
  • a plurality of series structures of ⁇ -type thermoelectric conversion cells using a temperature difference in the thickness direction of the insulating base material are arranged in parallel, and p-type and n-type are switched.
  • This element is a device having a topology in which the stages having the same potential during power generation are electrically connected.
  • the insulating base material is in the form of a sheet or a strip having heat insulating properties and flexibility, and has a base material strength capable of maintaining the shape of the base material alone in the use environment.
  • n-type spun yarn and p-type spun yarn made of conductive fibrous material having heat insulation properties are sewn alternately and in parallel to the insulating base material, and the front and back surfaces of the insulating base material are alternately placed. Are electrically connected to each other when penetrating them. Then, the insulating base material and the spun yarn are loosely bonded to each other, and the ⁇ -type thermoelectric conversion cell is connected in a vertical and horizontal form as an electric circuit in both series connection and parallel connection, increasing the resistance of the element to disconnection. .
  • the functional element of the present invention has a structure that is extremely resistant to disconnection, in which ⁇ -type thermoelectric conversion cells are connected vertically and horizontally in a mesh shape in both series connection and parallel connection.
  • the network structure in which the insulating base material and the spun yarn are loosely coupled to each other can provide an effect of suppressing a decrease in output due to the spun yarn being cut.
  • the n-type spun yarn and the p-type spun yarn made of the conductive fibrous substance are sewn so as to alternately penetrate the front surface and the back surface of the insulating base material.
  • a cell series structure of type thermoelectric conversion elements is formed, and the thickness of the element can be controlled with respect to the direction of temperature difference depending on the thickness of the insulating material.
  • a flexible thermoelectric conversion element can be provided. It is preferable that the thermal conductivity in the longitudinal direction of the conductive fibrous substance in the functional element of the present invention is suppressed to less than 10 W / mK.
  • the thermal conductivity in the longitudinal direction of the conductive fibrous substance is suppressed to less than 1 W / mK, and more preferably less than 0.1 W / mK.
  • the functional element of the present invention has heat insulation.
  • the thickness of the element is controlled in the temperature difference direction according to the thickness of the insulating material, and a sufficient temperature difference is provided between the front and back of the insulating material. Since the conductive fibrous substance penetrates between the front and back of the insulating material, the thermal conductivity in the longitudinal direction is suppressed rather than the radial direction (transverse direction) of the conductive fibrous substance.
  • the heat insulation of the functional element of the present invention is improved.
  • the entire flexible thermoelectric device of the functional element can be made heat insulating, and by improving the heat insulating properties of the conductive fibrous material, the overall heat insulating performance can be improved.
  • the flexible thermoelectric device using the functional element of the present invention assumes a use temperature (high temperature side) of about 35 (body temperature) to about 100 ° C., it can cope with natural air cooling as cooling on the low temperature side. is there. It is assumed that the thermal conductivity is markedly higher in the longitudinal direction than in the direction crossing the conductive fibrous material. In particular, in the case of carbon nanotubes (CNT), it can be inferred that the ratio reaches several tens to several hundred times.
  • CNT carbon nanotubes
  • the yarns are crossed and twisted and joined at least once. Is preferred.
  • the functional element of the present invention is such that when the n-type spun yarn and the p-type spun yarn pass through the front and back surfaces of the insulating base material alternately, the yarn is crossed, and the electrical connection by the conductive paste is made at the intersection It is preferable that the reinforcement is provided.
  • the yarn crosses or is brought into contact with each other, and the intersection or contact is adhered. It is preferable.
  • the n-type spun yarn and the p-type spun yarn penetrate obliquely with respect to the thickness direction of the insulating base material, and increase or decrease the portions exposed on the front and back surfaces of the insulating base material, respectively. It is preferable to have made it.
  • the n-type spun yarn and the p-type spun yarn are band-shaped, or the cross-section of the n-type spun yarn and the p-type spun yarn is polygonal or elliptical in order to reduce the thermal resistance at the exposed portion.
  • the shape is preferred. By making the cross section of the spun yarn a shape having a large specific surface area such as a rectangle, an ellipse, or a star, for example, the thermal resistance at the exposed portion can be reduced.
  • the insulating base material preferably has flexibility and heat insulating properties, specifically, cloth or paper, or foamed polymer, elastomer, cotton-like aggregate and gel-like aggregate. Any of those obtained by processing a material selected from the above into a plate shape or a sheet shape can be suitably used.
  • the cloth is a product obtained by processing a large number of fibers into a thin and wide plate, and includes woven fabric, knitted fabric (knitted fabric), lace, felt, non-woven fabric, silk fabric, and wool fabric.
  • the insulating base material is sewn, and it is preferable that the n-type spun yarn and the p-type spun yarn are sewn at the same time, and more preferably, That is, sewing was performed using warp and weft having substantially the same diameter as the thickness of the ⁇ -type thermoelectric conversion cell.
  • the spun yarn made of conductive fibrous materials includes carbon nanotubes (CNT), carbon nanofibers (CNF), graphene, graphene nanoribbons, fullerene nano whisker, and inorganic semiconductors.
  • CNT carbon nanotubes
  • CNF carbon nanofibers
  • a material made of a composite material of Graphene nanoribbons are described, for example, in the literature (H.
  • Sakaguchi et al. “Width-Controlled Sub-Nanometer Graphene Nanoribbon Films Synthesized by Radical-Polymerized Chemical Vapor Deposition”, Advanced Materials, Volume 26, Issue 24, pp. 4134-4138, 2014) discloses production methods and physical properties.
  • Fullerene nanowhiskers for example, have been disclosed in the literature (Junichi Miyazawa, “Synthesis and Properties of Fullerene Nanowhiskers”, Surface Science Vol. 28, No. 1, pp. 34-39, 2007) and their physical properties. Yes.
  • a twisted yarn (hereinafter referred to as “CNT spun yarn”) in which a plurality of fibers made of carbon nanotubes (CNT) having a diameter of 0.1 to 100 ⁇ m are twisted is preferably used. It can.
  • the diameter of one CNT is 1 to 2 nm, and may be up to about 10 nm as the thinnest when CNT is used as a fiber. From the viewpoint of mechanical strength, a CNT spun yarn having a diameter of at least 0.1 ⁇ m or more is used. .
  • a CNT spun yarn having a diameter of 100 ⁇ m or more can be realized by twisting many times, but since a workability when sewing alternately on the front surface and the back surface of the insulating base material is required, a diameter of 100 ⁇ m or less is required. CNT spun yarn is used.
  • CNT and composite materials thereof can be formed into a thread shape by taking advantage of the flexibility and high aspect ratio of CNT.
  • the CNT spun yarn By using the CNT spun yarn, a three-dimensional structure device can be manufactured without using a substrate processed into a complicated shape, and the length of the device with respect to the temperature difference direction can be freely controlled. Furthermore, it is expected that the conductivity and Seebeck coefficient will be improved due to the alignment of the CNTs in the longitudinal direction.
  • the shape of the spun yarn a wide range of applications can be expected as a material for textile electronics such as sewing directly on clothes.
  • the cocoon protein is inserted in the joint part of CNT with the fiber which consists of CNT.
  • thermoelectric conversion efficiency can be further improved by combining with a heat insulating base material. Furthermore, by encapsulating inorganic semiconductor particles in the basket-like protein, electrons or holes can be selectively tunnel-transported at the junction, and the conductivity and Seebeck coefficient can be improved.
  • the functional element manufacturing method of the present invention is the above-described functional element manufacturing method, and a current path is formed in a direction orthogonal to the direction of wave stitching by repeating the following steps 1) and 2).
  • a ⁇ -type structure series connection is formed along the current path.
  • Step 2 When the second spun yarn is wave-sewn adjacent to the first spun yarn that has been wave-stitched in parallel with the insulating base material, The portions exposed on the first surface of the first spun yarn that has been sewn are crossed, twisted at least once, and then sewn.
  • Step 2 Next, when the first spun yarn is wave-sewn adjacently in parallel with the second spun yarn that has been wave-stitched, the second surface is exposed to the second surface of the second spun yarn that has been sewn one step before. After crossing, twist at least once and sew.
  • thermoelectric conversion cells By simply sewing each n-type spun yarn and p-type spun yarn into an electrically and thermally insulating cloth-like substrate, not only a single thermoelectric conversion cell, but many thermoelectric conversion cells A structure for serial connection can be easily formed.
  • Such an element structure makes it easy to produce flexible thermoelectric devices with sufficient thickness, and applications of flexible thermoelectric devices that tend to be limited to heat dissipation to the atmosphere (such as pasting on the human body, building on buildings, etc.) ), It is easy to obtain a sufficient temperature difference between both surfaces of the element, and high conversion efficiency can be obtained.
  • thermoelectric device It is a method for producing a thermoelectric device that can be used in a scalable manner from an element having a thickness of about 1 mm suitable for use in the skin of clothes or a car seat to an element having a thickness of about 10 cm for use as a heat insulating material for buildings. Can be used in a wide range of applications.
  • the functional element of the present invention has an effect that it is possible to provide a heat-insulating flexible thermoelectric device having a sufficient thickness to obtain a temperature difference.
  • FIG. 3 is a diagram illustrating a method for manufacturing a functional element.
  • Correlation graph of immersion time, conductivity and Seebeck coefficient when carrier doping of CNT spun yarn using PEI Thermoelectric characteristics graph of functional elements
  • Flow chart of functional element manufacturing method Explanatory diagram about the effect of partial disconnection of functional elements
  • Schematic diagram of functional device of Example 3 Thermoelectric output characteristic graph of the functional element of Example 3
  • Equivalent circuit model of functional element used for simulation The graph which shows the change of the output of the functional element of Example 3 accompanying the change of a cutting probability.
  • thermoelectric conversion cell A series structure of ⁇ -type thermoelectric conversion cells using a temperature difference in the thickness direction will be described with reference to FIG.
  • the metal wiring connecting the n-type semiconductor portion and the p-type semiconductor portion which is often used in conventional thermoelectric conversion elements, is omitted for the sake of simplicity.
  • the ⁇ -type structured thermoelectric conversion cell is composed of a p-type semiconductor portion and an n-type semiconductor portion, and each cell is connected in series to become a thermoelectric conversion element.
  • an electromotive force is generated due to the Seebeck effect when a temperature difference occurs between the front surface and the back surface of the thermoelectric conversion element. Therefore, the thermoelectric conversion element heats one side (high temperature side) and cools the other side (low temperature side) to generate a temperature difference in the thermoelectric conversion element.
  • FIG. 2 (1) shows a connection topology of a series structure of five ⁇ -type thermoelectric conversion cells ( ⁇ -type thermocouples 1 to 5). Electrodes 1 and 2 are formed at both ends of the series structure, respectively. As shown in FIG. 1, each of the ⁇ -type thermocouples 1 to 5 generates power using a temperature difference in the thickness direction. Due to the electromotive force generated in the ⁇ -type thermocouple 1, the potential at the end of the ⁇ -type thermocouple 1 becomes V 1 from the potential (V 0 ) of the electrode 1. Similarly, due to the electromotive force generated in the ⁇ -type thermocouple 2, the potential at the end of the ⁇ -type thermocouple 2 becomes V2.
  • FIG. 2 (2) shows a connection topology in which five blocks are connected in parallel with a series structure of five ⁇ -type thermoelectric conversion cells as one block.
  • FIG. 3 shows the connection topology of the functional element of the present invention.
  • the functional element of the present invention has a topology in which stages at the same potential are connected at a portion where p-type and n-type are switched.
  • FIG. 3 when only the dotted line portion is viewed, only n-type or p-type is connected in the path.
  • FIGS. A structure equivalent to the connection topology shown in FIG. 3 is shown in FIGS.
  • ⁇ -type thermoelectric conversion cells are connected in series along a current path from the electrode 1 to the electrode 2. Further, the half-cells of the ⁇ -type thermoelectric conversion cells are connected in parallel. As a result, the ⁇ -type thermoelectric conversion cells are connected vertically and horizontally in a mesh pattern in both series connection and parallel connection.
  • each dotted line portion forms one ⁇ -type thermoelectric conversion cell.
  • each dotted line portion indicates one ⁇ -type thermoelectric conversion cell. 3 and 4 or 5 are equivalent in terms of topology.
  • FIG. 6 shows a case where a thin line for showing an electrical connection is removed from the connection described with reference to FIG. 4 or 5, and instead a p-type spun yarn or an n-type spun yarn is assumed and they are meandered and connected.
  • FIG. 6 when the three-dimensional structure is formed so that the portion indicated by the solid line is on the front side and the portion indicated by the dotted line is on the back side, each of the portions surrounded by the rectangle is one ⁇ -type thermoelectric conversion cell. It has become. That is, the topology is equivalent from FIG. 3 to FIG. The rectangle drawn in FIG.
  • 6 and symbols A to C are for showing examples of current paths that can be regarded as cell series connection in this element.
  • the area indicated by the symbol A is drawn when a combination of a p-type spun yarn side and an n-type spun yarn side that linearly connects one intersection of the p-type spun yarn and the n-type spun yarn is regarded as one ⁇ -type cell. ing. If the path is followed from the bottom to the upper left by two cells and then to the upper right by one cell, it can be regarded as a series connection of three cells.
  • four types of ⁇ -type cells can be defined by any combination of two p-type spun yarn sides and two n-type spun yarn sides.
  • a number of arbitrary series connection paths can be taken.
  • FIG. 7 shows a schematic diagram of the functional element of this example.
  • the functional element of the present invention is a p-type spun yarn 1 in which a p-type spun yarn 1 and a n-type spun yarn 2 of conductive nanofibers are sewn into a sheet-like insulating substrate 3 such as a nonwoven fabric.
  • the n-type spun yarn 2 is sewn so as to be joined to each other when the front and back surfaces of the insulating base material 3 are wave-sewn and alternately penetrate the front and back surfaces.
  • four p-type spun yarns 1 and three n-type spun yarns 2 are alternately twisted once when the yarns cross each other when passing through the front and back surfaces of the insulating base material alternately. Are joined together.
  • Each of the p-type spun yarn 1 and the n-type spun yarn 2 is provided with six seams.
  • a structure is formed in which ⁇ -type thermoelectric conversion cells are connected vertically and horizontally in a mesh pattern in both series connection and parallel connection.
  • the network structure shown in FIG. 7 can be called a structure having 3.5 units in series and 12 units in parallel.
  • the number of mesh structure elements in series means that the number of units of the ⁇ -type thermoelectric conversion cell is counted in the connection direction of the voltage drop connecting the potentials of the counter electrodes
  • the number of nodes in parallel means that the nodal points of thermoelectric yarns are counted in the connection direction connecting the equipotentials, and twice the number of nodal points of the row with the smallest number of nodal points.
  • thermoelectric yarn not connected to the next stage at both ends it is defined as reducing it.
  • a copper wire 4 having a lower electrical resistance than that of the conductive nanofiber spun yarn is used, which is a current harvesting wiring.
  • the copper wire 4 is sewn so as to alternately pass through the front surface and the back surface of the insulating base material 3, and is engaged with the p-type spun yarn on the front surface and the back surface of the insulating base material 3.
  • the copper wire is connected only to both ends of the p-type spun yarn, but may be connected to each seam.
  • a silver paste 5 is applied to a portion where the p-type spun yarn 1, the n-type spun yarn 2 and the copper wire 4 are engaged to reinforce the electrical connection at the intersection.
  • it is not restricted to a silver paste, Various conductive pastes, such as a carbon paste, may be sufficient.
  • a CNT spun yarn will be described as a spun yarn of conductive nanofibers.
  • NanoIntegris manufactured by HiPCO method (a method of growing iron monoxide as a catalyst and carbon monoxide as a carbon source) was used. Ultrasonically dispersed and dispersed in a 3% by weight aqueous solution of SDS (Sodium Dodecyl Sulfate). With reference to FIG. 8, a method for producing CNT spun yarn will be described. First, the CNT dispersant 11 placed in the dispenser 12 was ejected to the agglomerate 15 in the container 14 placed on the turntable 13, thereby performing hydrodynamic stretching spinning. The aggregating liquid 15 was a 5 wt% PVA (Polyvinyl alcohol) aqueous solution.
  • PVA Polyvinyl alcohol
  • Spinning CNT16 is produced by adjusting the direction and position of the nozzle of the dispenser 12 so that the rotation speed is approximately 50 rpm and parallel to the water flow at a distance of about 3 cm from the central axis, and discharging the CNT dispersant 11. did. Thereafter, the solvent was replaced with pure water, and the spun CNT 16 was pulled up from one end and dried in the air to prepare a CNT spun yarn.
  • the diameter of the obtained CNT spun yarn was about 10 to 30 ⁇ m.
  • Thermoelectric measurement was performed on the obtained CNT spun yarn.
  • the measurement results are shown in Table 1 below.
  • Table 1 shows the measurement results of the non-oriented CNT thin film produced under the same dispersion conditions as the CNT spun yarn for comparison. All measurements were performed in the atmosphere.
  • the CNT spun yarn showed a decrease in conductivity compared to the CNT thin film, but the power factor increased 2.9 times compared to the CNT thin film due to an increase in Seebeck coefficient.
  • the conductivity decreased. This is presumed to be due to the decrease in the number of carriers due to the movement of holes to PVA, and the fact that PVA, which is an insulator, entered between the CNTs when forming the spun yarn.
  • the Seebeck coefficient of CNT spun yarn is greatly increased, the possibility that PVA that has entered between CNTs has enhanced the Seebeck effect at the CNT junction as well as the movement of holes to PVA. There is.
  • thermoelectric performance it is possible to control the CNT carrier and interface by selecting an appropriate flocculant, and there is a possibility of further improving thermoelectric performance by selecting an appropriate flocculant. . Further, the thermoelectric performance can be improved by optimizing the carrier density by carrier doping described later.
  • Carrier doping of CNT spun yarn was performed using PEI (Polyethyleneimine) known as an n-type dopant.
  • the n-type doping was performed by immersing the CNT spun yarn in a 1% by weight PEI aqueous solution (solvent: methanol) for a predetermined time.
  • FIG. 12 shows the relationship between the immersion time, the conductivity, and the Seebeck coefficient. When the CNT spun yarn is immersed in PEI and doped for a sufficient time, the Seebeck coefficient changes to n-type, and it can be seen that PEI functions as a donor.
  • the Seebeck coefficient S is a sum of Seebeck coefficients having the weights of the conductivity of each of electrons and holes, as in the following Equation 1.
  • S e is the electron Seebeck coefficient
  • S h is the Seebeck coefficient of the Hall
  • [delta] e is the electron conductivity
  • the [delta] h is the conductivity of the hole.
  • FIG. 9 shows a state in which one p-type CNT spun yarn is wave-sewn on the insulating base material 3.
  • the p-type CNT spun yarn 1a is sewn by wave stitching in a straight line so as to alternately penetrate the front surface and the back surface of the insulating base material 3. .
  • FIG. 10 shows a state in which p-type CNT spun yarn and n-type CNT spun yarn are sewn one by one in parallel.
  • the n-type CNT spun yarn 2a is sewn in parallel to the p-type CNT spun yarn 1a in a state where the p-type CNT spun yarn 1a is sewn into the insulating base material 3.
  • FIG. 4 when the n-type CNT spun yarn 2a is sewn, it is sewn so as to alternately penetrate the front and back surfaces of the insulating base material 3 in the same manner as when the p-type CNT spun yarn 1a is sewn. It is rare.
  • the p-type CNT spun yarn 1a and the n-type CNT spun yarn 2a are joined by being twisted once and engaged by joining the portions exposed on the surface of the insulating base material 3. .
  • silver paste is applied to the engaged intersections to reinforce the electrical connection.
  • FIG. 11 shows a state in which four p-type CNT spun yarns and four n-type CNT spun yarns are sewn.
  • the p-type CNT spun yarn 1b is sewn into the insulating base material 3, as shown in FIG. 11, the front and back surfaces of the insulating base material 3 are alternated in the same manner as when the p-type CNT spun yarn 1a is sewn. It is sewn so as to penetrate through. Then, the p-type CNT spun yarn 1b and the n-type CNT spun yarn 2a are engaged by twisting once, with the portions exposed on the back surface of the insulating base material 3 intersecting each other. Although not shown here, silver paste is applied to the engaged intersections to reinforce the electrical connection.
  • the n-type CNT spun yarn 2b is sewn.
  • the method for sewing the n-type CNT spun yarn 2b is the same as the method for sewing the n-type CNT spun yarn 2a.
  • the method for weaving the p-type CNT spun yarn 1b and the n-type CNT spun yarn 2b is the same as the method for weaving the p-type CNT spun yarn 1a and the n-type CNT spun yarn 2a.
  • the p-type CNT spun yarn 1c is sewn.
  • the method for sewing the p-type CNT spun yarn 1c is the same as the method for sewing the p-type CNT spun yarn 1b.
  • the method for weaving the n-type CNT spun yarn 2b and the p-type CNT spun yarn 1c is the same as the method for weaving the n-type CNT spun yarn 2a and the p-type CNT spun yarn 1b.
  • the n-type CNT spun yarn 2c is sewn.
  • the method for sewing the n-type CNT spun yarn 2c is the same as the method for sewing the n-type CNT spun yarn (2a, 2b).
  • the p-type CNT spun yarn 1c and the n-type CNT spun yarn 2c are knitted in the p-type CNT spun yarn 1a and the n-type CNT spun yarn 2a, or the p-type CNT spun yarn 1b and the n-type CNT spun yarn 2b. This is the same as the weaving method.
  • the p-type CNT spun yarn 1d is sewn.
  • the method for sewing the p-type CNT spun yarn 1d is the same as the method for sewing the p-type CNT spun yarn (1b, 1c).
  • the n-type CNT spun yarn 2c and the p-type CNT spun yarn 1d are knitted by the n-type CNT spun yarn 2a and the p-type CNT spun yarn 1b or the n-type CNT spun yarn 2b and the p-type CNT spun yarn 1c. This is the same as the weaving method.
  • the adjacent n-type CNT spun yarn 2 before one step is knitted on the back surface, and when the n-type CNT spun yarn 2 is sewn, it is adjacent.
  • the p-type CNT spun yarn 1 before one step is knitted into the insulating base material 3 so as to be knitted on the back surface.
  • FIG. 14 shows a flowchart of a method for manufacturing a functional element of the present invention.
  • the p-type spun yarn is wave-stitched linearly on the insulating base material (step S01).
  • step S01 the n-type spun yarn is wave-sewn adjacent to the wave-sewn p-type spun yarn in parallel, the portion exposed on the surface of the p-type spun yarn sewed one step before on the surface intersects. And sew after twisting once (step S02).
  • step S02 sew after twisting once
  • step S03 After being twisted, sewing is performed (step S03). Steps 2 and 3 are repeated as many times as necessary (step S04).
  • step S01 good conductor thin wires are used instead of p-type spun yarn, and the final step S03 is repeated.
  • a good conductor fine wire instead of using the p-type spun yarn, a good conductor fine wire may be used.
  • the direction perpendicular to the direction of wave stitching is a current path, and a ⁇ -type structure series connection is formed along the current path. In other words, the equipotential points are laterally connected in parallel.
  • FIG. 15 (1) shows a conventional thermoelectric conversion element based on a ⁇ -type structure series structure in which three sets of series connection units are juxtaposed in order to obtain a sufficient amount of generated power by increasing the area. Yes. These three sets of series connection units are connected in parallel outside the element.
  • this element let us consider a case in which a break occurs in the current path at the location indicated by the cross in the figure. As a result of this disconnection at one place, one set of series connection units painted in gray completely stops the power generation operation.
  • a large-area element in which 10 sets of 10 ⁇ -type cells connected in series are juxtaposed and connected externally in parallel. In this large-area element, if the spun yarn breaks at one place, the total electric conductance becomes 90% (that is, the electric resistance is about 110%), and the maximum power generation amount is also reduced to 90%. That is, a 10% reduction in generated power occurs.
  • FIG. 15 (2) shows a thermoelectric conversion element having a network structure of functional elements of the present invention.
  • a case is considered in which a disconnection occurs in the current path at a location indicated by a cross in the figure. Due to this disconnection at one location, the ⁇ -type half-cells painted in gray cease to generate electricity, but since the topology of the current path is a network structure, they are considered to belong to the same ⁇ -type structure cell. Since current paths are secured in all cells including adjacent half-cells capable of generating power, the power generation operation other than the disconnected seam portion is not affected. For example, consider a large-area device having a network structure of ⁇ -type cells 10 ⁇ 10 units.
  • the total number of cells is the same as that of the large-area element by the conventional series connection described above.
  • the total electric conductance is about 99% (that is, the electric resistance is about 101%), and the maximum power generation amount is about 99%. That is, the decrease in generated power is suppressed to 1%.
  • thermoelectric characteristics of the functional element of the present invention The p-type spun yarn obtained by spinning the CNT composite material by the method shown in FIG. 8 and the n-type spun yarn doped by the method shown in FIG. Thus, the thermoelectric characteristics of the functional element having the network structure shown in FIG. 7 were evaluated.
  • a thermoelectric output characteristic graph of the functional element is shown in FIG. From Table 2, it can be seen that the open-circuit voltage increases in proportion to the temperature difference between the front surface and the back surface. Further, as shown in FIG. 13, the output characteristics are also characteristics as shown in the theory that the output power draws a parabola with respect to the voltage according to the load resistance.
  • This functional element has sufficient flexibility, and it was confirmed that the element resistance did not change with respect to bending, twisting, and pulling of about several percent. In addition, it is confirmed that an output corresponding to a temperature difference of 5 to 10 ° C can be obtained by simply touching one side with the hand in the atmosphere because of the use of a heat insulating base material and a CNT composite material spun yarn having low thermal conductivity. It was.
  • a functional element having the same structure as that of Embodiments 1 and 2 and having higher performance will be described.
  • the structure of the functional element of this example is the same as the schematic diagram of the functional element shown in FIG. That is, in the functional element of this example, as shown in FIG. 7, the p-type spun yarn 1 and the n-type spun yarn 2 of conductive nanofibers are sewn into a sheet-like insulating substrate 3 such as a nonwoven fabric.
  • the p-type spun yarn 1 and the n-type spun yarn 2 are sewn so that the front and back surfaces of the insulating base material 3 are corrugated and joined together when alternately penetrating the front and back surfaces. It is rare.
  • FIG. 7 the schematic diagram of FIG.
  • the p-type spun yarn 1 and the n-type spun yarn 2 are each provided with six stitches so that the ⁇ -type thermoelectric conversion cells can be connected vertically and horizontally in both a series connection and a parallel connection.
  • three p-type spun yarns 1 and 2 are formed.
  • the n-type spun yarn 2 passes through the front and back surfaces of the insulating base material alternately, the yarns are crossed, twisted once, engaged and joined, and the p-type spun yarn 1 and the n-type spun yarn are joined.
  • Each thread 2 is provided with seven seams, so that the ⁇ -type thermoelectric conversion cells are vertically connected in a mesh shape in both series connection and parallel connection.
  • a horizontally connected structure (2.5 units in series, 14 units in parallel) is formed.
  • the copper wire 4 is connected only to both ends of the p-type spun yarn, that is, only to the end of the series structure of the ⁇ -type thermoelectric conversion cell. It was set as the structure where a copper wire is connected for every. That is, the copper wire 4 is sewn so as to alternately penetrate the front surface and the back surface of the insulating base material 3, and on the front surface and the back surface of the insulating base material 3, it intersects with the p-type spun yarn for each stitch. And connected to a ⁇ -type thermoelectric conversion cell for each stitch.
  • copper wire, p-type spun yarn, n-type spun yarn, p-type spun yarn, n-type spun yarn, p-type spun yarn, copper wire are sewn in this order, and the copper wire and p-type spun yarn intersect at each stitch. It has been made to.
  • a silver paste 5 was applied to the portion where the p-type spun yarn 1, the n-type spun yarn 2 and the copper wire 4 were engaged in order to reinforce the electrical connection at the intersection.
  • the method for producing the CNT spun yarn is the same as in Example 1, but the CNTs used and the aggregating liquid are different, and the diameter of the produced CNT spun yarn is different. Similar to the first embodiment, description will be made with reference to FIG. CNT used what was made using eDIPS method (enhanced Direct Injection Pyrolytic Synthesis method). Ultrasonically dispersed, dispersed in a 3% by weight aqueous solution of SDS (Sodium Dodecyl Sulfate), and further 0.01% by weight of polyethylene glycol was added as a binder. As shown in FIG.
  • SDS sodium Dodecyl Sulfate
  • the CNT dispersant 11 placed in the dispenser 12 was ejected to the agglomerate 15 in the container 14 placed on the turntable 13, thereby hydrodynamically drawing and spinning.
  • pure methanol was used as the aggregating liquid 15.
  • Spinning CNT16 is produced by adjusting the direction and position of the nozzle of the dispenser 12 so that the rotation speed is approximately 50 rpm and parallel to the water flow at a distance of about 3 cm from the central axis, and discharging the CNT dispersant 11. did. Thereafter, the solvent was replaced with pure water, and the spun CNT 16 was pulled up from one end and dried in the air to prepare a CNT spun yarn.
  • the obtained CNT spun yarn had a diameter of about 30 to 50 ⁇ m, and a spun yarn thicker than the CNT spun yarn of Example 1 (diameter of about 10 to 30 ⁇ m) could be produced.
  • [BMIM] PF 6 known as an ionic liquid was used for n-type doping of CNT spun yarn.
  • DMSO Dimethyl sulfoxide
  • the CNT spun yarn was immersed for 24 hours for doping.
  • DMSO has a role to help [BMIM] PF 6 penetrate into the CNT spun yarn.
  • the ionic liquid adhering to the CNT spun yarn after immersion was wiped off with an experimental cotton cloth.
  • thermoelectric properties of functional elements The thermoelectric characteristics of the functional element of this example were evaluated.
  • a thermoelectric output characteristic graph of the functional element of this example is shown in FIG. Due to improvements in the CNT spun yarn production method and doping method, an equivalent output voltage was obtained despite the fact that the number of series was smaller compared to FIG. 13 (in the case of FIG. 13, the number of series is 3.5 units). In contrast, in the case of FIG. 17, the number of series is 2.5 units), and the output power is increased. In addition, the output power has a theoretical characteristic that draws a parabola with respect to the voltage according to the load resistance.
  • the functional element of this example had sufficient flexibility, and it was confirmed that the element resistance did not change with respect to bending, twisting, and pulling of about several percent.
  • thermoelectric characteristics before and after the disconnection of the functional element of this example will be described. As shown in FIG. 18, the thermoelectric characteristics after cutting only one of the disconnection points 8 were evaluated. Table 4 below shows the maximum power generation amount before and after cutting at one place in the functional element of this example. From Table 4 below, it can be seen that the maximum power generation amount is increased in proportion to the square of the temperature difference between the front surface and the back surface. The element resistance was 239 ⁇ before cutting and 262 ⁇ after cutting.
  • this functional element In evaluating the influence of the disconnection of the maximum power generation amount, this functional element is rich in flexibility and stretchability, so it is difficult to make the applied temperature difference and the distribution in the element strictly constant. There are challenges. As a result, variations in measurement values and fluctuations due to time occur, and the influence is reduced by taking the average of the relative values of the generated power at each temperature in Table 4.
  • the average value of the amount of generated power at each temperature in Table 4 is 0.994, and it is determined that the decrease in maximum output is only about 0.6% due to disconnection at one location. This is slightly better than the theoretically predicted 2.5%, but it is judged to be a reasonable value considering the above error factors.
  • the element conductance is 0.912 times, and it is determined that the decrease due to disconnection at one place is about 8.8%. This is slightly larger than the theoretically predicted value of 4.8%, but is estimated to be an error due to variation in the resistance value of each cell.
  • FIG. 19 shows an equivalent circuit model of the functional element used in the simulation.
  • the equivalent circuit model of FIG. 19 is a model in which an equivalent circuit from a node point to a node point in a p-type or n-type thermoelectric yarn is represented by a voltage source as indicated by reference numeral 21.
  • each voltage source can provide a thermoelectromotive force of V p or V n , and a resistor R is connected in series inside the voltage source (not shown).
  • the value of the resistance R of each voltage source (V1 to V60) is set so large that it can be regarded as infinite with a given cutting probability, and the others are set to 100 ⁇ , and the voltage and current generated in the circuit was calculated.
  • voltage sources (V61, V62) are voltage sources used for obtaining the current-voltage characteristics of the element, and these have an internal resistance of 0 (zero).
  • a triangular mark indicated by reference numeral 22 represents a reference potential (0 V).
  • FIG. 20 shows the change in the output of the functional element as a result of changing the cutting probability of the CNT spun yarn constituting the stitch from 0 to 50% and trying 100 times each.
  • the vertical axis of the graph shown in FIG. 20 represents the maximum output power of the functional element normalized by the output when there is no disconnection, the error bar represents the maximum and minimum of the 100 trial results, “O” represents the average.
  • the output expected for the functional element decreases almost linearly as the cutting probability increases. However, even if the cutting probability is 50%, the output of the functional element still remains. It has been shown that the output is likely to remain.
  • the functional element of the present invention is a distributed power source for forming a sensor matrix for a smart house or smart building, or a thermoelectric conversion element for reusing exhaust heat energy in a house, office, or automobile as an energy harvesting element It can be used as a power source for sticker-type biological information measuring instruments (body temperature, pulse, electrocardiogram monitor, etc.).
  • the thermoelectric conversion element has the same structure as the thermocouple, the functional element of the present invention is a highly versatile planar high-sensitivity internal / external temperature difference sensor, automobile seat, office chair or carpet.
  • the functional element of the present invention is a cloth-like Peltier cooling used for seats and backrests of automobiles, trains, airplanes, etc. It can also be used for devices and clothing with heating and cooling functions.

Abstract

Provided is a functional element resistant to disconnection, comprising a structure for obtaining a flexible thermoelectric device with a sufficient thickness for obtaining a temperature difference, the structure having a textile structure in which threads configured from thermoelectric material are stitched into a flexible insulating base material having a small thermal conductivity. In an element structure, a plurality of serial structures of π-type thermoelectric conversion cells that utilize a temperature difference in the thickness direction of an insulating base material are arranged in parallel, the element structure having a topology in which, at portions where p-type and n-type are switched, stages that have the same potential during electric power generation are electrically connected, wherein the π-type thermoelectric conversion cells are connected as electric circuits both lengthwise and widthwise in a mesh via serial connection and parallel connection. In this way, a functional element can be provided that is not susceptible to deterioration in output characteristics due to disconnection. Specifically, an n-type spun yarn and a p-type spun yarn comprising an electrically conductive fibrous substance are stitched into a sheet of insulating base material alternately and in parallel, wherein the n-type spun yarn and the p-type spun yarn are electrically connected when respectively alternately penetrating through a front surface and a back surface of the insulating base material.

Description

π型熱電変換素子のセル直列構造を有する機能性素子とその作製方法Functional element having cell series structure of π-type thermoelectric conversion element and method for producing the same
　本発明は、フレキシブル熱電デバイスを構成できる機能性素子ならびにその作製技術に関するものである。 The present invention relates to a functional element that can constitute a flexible thermoelectric device and a manufacturing technique thereof.
　近年、身の周りの未利用のエネルギーを回収して利用する、エナジーハーベスティングが注目を集めている。このような技術の中でも、熱を回収して電気エネルギーに変換する熱電変換技術への期待が大きい。身の回りで利用されているエネルギー全体量の約７０％が活用されることなく排熱となっているからである。
　しかし、従来の面積単価の高い熱電変換素子では経済的メリットが得にくいとう理由から、これまでのところ限定的な利用に留っている。そこで、大面積に対して低コストで利用でき、様々な形状の表面に対応できる柔軟性があり軽量化が図られた大面積フレキシブル熱電デバイスを実現することにより、使用用途が大きく広がる可能性がある。例えば、スマートビルディングなどで用いるセンサーネットワークにおける分散型自立電源や、体温による小型電気デバイスの駆動電源などに用いることが期待できる。 In recent years, energy harvesting, which collects and uses unused energy around us, has attracted attention. Among such technologies, there is a great expectation for a thermoelectric conversion technology that recovers heat and converts it into electrical energy. This is because about 70% of the total amount of energy used around us is exhausted without being utilized.
However, the conventional thermoelectric conversion element with a high unit area price has so far been limited in use because it is difficult to obtain economic merit. Therefore, the use of large area flexible thermoelectric devices that can be used at a low cost for large areas, can be applied to various shapes of surfaces, and is lightweight has the potential to broaden the application. is there. For example, it can be expected to be used as a distributed self-sustained power source in a sensor network used in a smart building or the like, or a power source for driving a small electric device by body temperature.
　このような背景から有機材料や有機無機複合材料が有望な熱電材料として注目され始め、研究の発展とともにその性能は大きく向上してきた。しかし、多くの有機材料はもともと電極やトランジスタ、太陽電池材料として使用することを念頭に開発されてきた。そのため、薄膜での利用が一般的であり、熱電デバイスに必要な十分な厚みの高品質な熱電変換材料を得ることは容易ではない。 From this background, organic materials and organic-inorganic composite materials have begun to attract attention as promising thermoelectric materials, and their performance has greatly improved with the development of research. However, many organic materials have been originally developed with the use of electrodes, transistors, and solar cell materials in mind. Therefore, the use with a thin film is common, and it is not easy to obtain a high-quality thermoelectric conversion material having a sufficient thickness necessary for a thermoelectric device.
　一般に、熱電変換材料の性能は、パワーファクターＰＦ（＝α2σ）及び無次元性能指数ＺＴ（＝α2σＴ／κ）で評価される。ここで、αはゼーベック係数、σは導電率、κは熱伝導率、Ｔは絶対温度である。パワーファクターＰＦは、熱電変換材料から得られる電力に対応し、無次元性能指数ＺＴは、エネルギー変換効率に対応しており、共に値が大きい方が熱電変換材料としての性能が良い。熱電変換素子の変換効率は、理想的にはＺＴのみで決まり、デバイス構造に依存しない。 In general, the performance of a thermoelectric conversion material is evaluated by a power factor PF (= α 2 σ) and a dimensionless figure of merit ZT (= α 2 σT / κ). Where α is the Seebeck coefficient, σ is the conductivity, κ is the thermal conductivity, and T is the absolute temperature. The power factor PF corresponds to the electric power obtained from the thermoelectric conversion material, and the dimensionless figure of merit ZT corresponds to the energy conversion efficiency. The larger the value of both, the better the performance as the thermoelectric conversion material. The conversion efficiency of the thermoelectric conversion element is ideally determined only by ZT and does not depend on the device structure.
　これは温度差ΔＴがついた定常状態において、全ての熱流が熱電材料を通じて低温側に流れているという仮定のもとに導出された指標であり、実際のデバイスではΔＴは材料だけではなくデバイス構造にも依存し、厚みが厚いほどまた熱伝導率が小さいほどΔＴは大きくなる。つまり、無次元性能指数ＺＴはデバイス構造に依存しない値であるが、実際の熱電デバイスの出力や効率はデバイス構造に大きく依存することになる。
　例えば、体温３７℃、外気温２２℃の１５℃の温度差がついた界面に対して、熱伝導率が０．１Ｗ／ｍＫのデバイスを貼り付けるとすると、温度差を１０℃つけるためには５ｍｍ程度の厚みが必要となる。仮に２００μｍ程度の小さい厚みでは、１℃程度の温度差しかつかない。室温付近では熱電デバイスの効率と温度差には、ほぼ線形の関係があることから、熱電デバイスの厚みと熱電効率の関係は、厚みが大きくなると温度差は１５℃に近づき、熱電効率が飽和する。高い熱電効率を得るためには、熱電デバイスに十分な膜厚が必要なのである。 This is an index derived under the assumption that all heat flows to the low temperature side through the thermoelectric material in a steady state with a temperature difference ΔT. In an actual device, ΔT is not only a material but also a device structure. In other words, ΔT increases as the thickness increases and the thermal conductivity decreases. That is, the dimensionless figure of merit ZT is a value that does not depend on the device structure, but the output and efficiency of the actual thermoelectric device greatly depend on the device structure.
For example, if a device with a thermal conductivity of 0.1 W / mK is attached to an interface with a temperature difference of 15 ° C. with a body temperature of 37 ° C. and an outside air temperature of 22 ° C., A thickness of about 5 mm is required. If the thickness is as small as about 200 μm, the temperature is only about 1 ° C. Since the efficiency and temperature difference of the thermoelectric device have a substantially linear relationship near room temperature, the relationship between the thickness of the thermoelectric device and the thermoelectric efficiency approaches 15 ° C. as the thickness increases, and the thermoelectric efficiency is saturated. . In order to obtain high thermoelectric efficiency, a sufficient film thickness is necessary for the thermoelectric device.
　特に、ゼーベック効果によって生じる熱起電力はデバイスの低温側と高温側の温度差に比例することから、デバイスに十分な温度差をつけることが重要となる。
　しかしながら、デバイスの低温側と大気中との界面には対流熱抵抗が存在しているため、高温側からの熱流がせき止められ、薄膜形状（数百μｍ）では殆ど温度差がつかないという実態がある。また、薄膜材料でミリメートルオーダーの膜厚を成膜するのは困難である。従来のフレキシブル熱電デバイスは、薄膜材料を使用していることから、その厚みは２００μｍ程度以下であり、実用的な高出力が得られ難いという問題点があった。 In particular, since the thermoelectromotive force generated by the Seebeck effect is proportional to the temperature difference between the low temperature side and the high temperature side of the device, it is important to give a sufficient temperature difference to the device.
However, since there is convective thermal resistance at the interface between the low temperature side of the device and the atmosphere, the heat flow from the high temperature side is blocked, and there is almost no temperature difference in the thin film shape (several hundred μm). is there. Moreover, it is difficult to form a film thickness on the order of millimeters with a thin film material. Since the conventional flexible thermoelectric device uses a thin film material, its thickness is about 200 μm or less, and there is a problem that it is difficult to obtain a practical high output.
　そのため、熱電デバイスの面内方向に対して温度差をつける（例えば、非特許文献１を参照）、或は、薄膜をスタックすることによって熱電デバイスの厚み方向に温度差をつけている（例えば、非特許文献２を参照）。多くが前者、すなわち、面内方向に対して温度差をつける方法を用いているが、この方法ではフレキシブル熱電デバイスの用途として考えられる医療用モニタリングやスマートビルディングなどの分散型電源として使用することができず、使用用途が限定されてしまうといった問題がある。また、後者、すなわち、厚み方向に温度差をつける方法では、膜厚制御が困難であり、また基板が必要となることから、熱流の多くが基板を通じて流れるため、効率が低下してしまうといった問題がある。 Therefore, a temperature difference is made with respect to the in-plane direction of the thermoelectric device (for example, see Non-Patent Document 1), or a temperature difference is made in the thickness direction of the thermoelectric device by stacking thin films (for example, (Refer nonpatent literature 2). Many use the former, that is, the method of creating a temperature difference in the in-plane direction, but this method can be used as a distributed power source for medical monitoring and smart buildings that can be considered as a flexible thermoelectric device application. There is a problem that the usage is limited. Further, in the latter case, that is, the method in which the temperature difference is made in the thickness direction, it is difficult to control the film thickness, and since a substrate is required, a large amount of heat flow flows through the substrate, resulting in a decrease in efficiency. There is.
　一方、織物構造体を形成する熱電デバイスが知られている。例えば、消防衣服などの耐熱防護服用の生地として用いられ、環境温度を定量的に測定することが可能な熱電対含有織物がある（特許文献１を参照）。これは、複数の経糸と複数の緯糸とが交差して織られ、経糸同士の間又は緯糸同士の間に、少なくとも一対の第一の熱電対素線と第二の熱電対素線が織り込まれている熱電対含有織物である。すなわち、織糸の間に熱電対素線を織り込んだものである。また、実質的に横糸方向を向くような複数のワイヤの網状組織により形成される熱電構造体がある（特許文献２を参照）。
　また、絶縁性繊維からなる経糸に、熱電対を形成する２種の金属繊維Ｘと金属繊維Ｙとを交互に緯糸として織り込まれたもので、全体として緯糸が金属繊維Ｘと金属繊維Ｙとからなる熱電対列を形成する熱電変換材料が知られている（特許文献３を参照）。 On the other hand, thermoelectric devices that form woven structures are known. For example, there is a thermocouple-containing fabric that is used as a fabric for heat-resistant protective clothing such as fire-fighting clothing and that can quantitatively measure the environmental temperature (see Patent Document 1). This is because a plurality of warp yarns and a plurality of weft yarns are woven in an intersecting manner, and at least a pair of first thermocouple wires and second thermocouple wires are woven between warp yarns or between weft yarns. A thermocouple-containing fabric. That is, a thermocouple wire is woven between the woven yarns. In addition, there is a thermoelectric structure formed by a network of a plurality of wires substantially facing the weft direction (see Patent Document 2).
In addition, two kinds of metal fibers X and metal fibers Y forming a thermocouple are alternately woven into the warp made of insulating fibers as wefts. As a whole, the wefts are composed of the metal fibers X and the metal fibers Y. The thermoelectric conversion material which forms the thermocouple row | line which becomes is known (refer patent document 3).
　特許文献１の熱電デバイスの場合、電極を形成しなければならず、金属線を利用していることから熱電効率が大きく低下することが問題である。また、特許文献２の熱電構造体の場合、熱電対としての使用を想定しており、π型構造をもっていないことから熱電効率が悪いことが問題である。さらに、特許文献１の熱電デバイスと特許文献２の熱電構造体と特許文献３の熱電変換材料の全てが、温度差を面内方向につける構造になっており、厚さ方向につける構造になっていない。 In the case of the thermoelectric device of Patent Document 1, an electrode has to be formed, and the problem is that the thermoelectric efficiency is greatly reduced because a metal wire is used. Moreover, in the case of the thermoelectric structure of patent document 2, the use as a thermocouple is assumed and since it does not have a pi-type structure, it is a problem that thermoelectric efficiency is bad. Furthermore, the thermoelectric device of Patent Document 1, the thermoelectric structure of Patent Document 2, and the thermoelectric conversion material of Patent Document 3 all have a structure in which the temperature difference is applied in the in-plane direction, and the structure is provided in the thickness direction. Not.
特開２０１０－０９０４９２号公報JP 2010-090492 A 特開２００７－３２９４５６号公報JP 2007-329456 A 特開弊１０－９９６９号公報Japanese Patent Application Laid-Open No. 10-9969
　上述の如く、従来のフレキシブル熱電デバイスでは、熱起電力はデバイスの低温側と高温側の温度差に比例することから、デバイスに十分な温度差をつけることが重要であるにも関わらず、数百μｍ程度の薄膜形状では殆ど温度差がつかないという問題があった。
　また、熱電デバイスを構成するＰ型とＮ型の半導体層とは別に、それらを直列に多数接続する電極を形成する必要があり、界面抵抗の増加による熱電効率の低下、経時劣化、プロセスの複雑化などの問題があった。 As described above, in the conventional flexible thermoelectric device, the thermoelectromotive force is proportional to the temperature difference between the low temperature side and the high temperature side of the device, so it is important to make a sufficient temperature difference between the devices. The thin film shape of about 100 μm has a problem that there is almost no temperature difference.
In addition to the P-type and N-type semiconductor layers that make up the thermoelectric device, it is necessary to form a large number of electrodes connected in series, resulting in a decrease in thermoelectric efficiency due to an increase in interface resistance, deterioration over time, and complexity of the process. There were problems such as conversion.
　上記状況に鑑みて、本発明は、温度差を得るための十分な厚みがあるフレキシブル熱電デバイスを得るための構造として、熱電材料によって構成され十分な柔軟性と機械的強度を持つ糸が、熱伝導率の小さいフレキシブルな絶縁性基材に縫い込まれた織物構造を有する機能性素子およびその作製方法を提供することを目的とする。また、断線に対して出力特性が低下しにくい機能性素子およびその作製法を提供することを目的とする。
　なお、本明細書において、機能性素子は、発電を目的とする素子、冷却／加熱を目的とする素子、温度センシングを目的とする素子など様々な機能を発揮できる素子という意味で用いている。 In view of the above situation, the present invention provides a structure for obtaining a flexible thermoelectric device having a sufficient thickness for obtaining a temperature difference, and a yarn composed of a thermoelectric material and having sufficient flexibility and mechanical strength is heated. It is an object of the present invention to provide a functional element having a fabric structure sewn on a flexible insulating base material having a low conductivity and a method for manufacturing the functional element. It is another object of the present invention to provide a functional element in which output characteristics are unlikely to deteriorate with respect to disconnection and a manufacturing method thereof.
In this specification, a functional element is used to mean an element capable of exhibiting various functions such as an element for power generation, an element for cooling / heating, and an element for temperature sensing.
　上記目的を達成すべく、本発明の機能性素子は、絶縁性基材の厚み方向の温度差を利用するπ型熱電変換セルの直列構造が複数並列に並び、ｐ型とｎ型が切り換わる部位で、発電時に同電位となる段間が電気的に接続されるトポロジーを有する素子である。絶縁性基材は、断熱性と柔軟性を有するシート状または帯状で、使用環境において基材単体で形状保持し得る基材強度を有する。素子は、断熱性を有する導電性繊維状物質から成るｎ型紡績糸とｐ型紡績糸が、絶縁性基材に交互かつ並行して縫い込まれ、それぞれ絶縁性基材の表面と裏面を交互に貫通する際に互いに電気的に接続されている。そして、絶縁性基材と紡績糸が互いに緩やかに結合し、π型熱電変換セルが電気回路として直列接続と並列接続の両方で網目状に縦横に接続され、断線に対する素子の耐性を高めている。本発明の機能性素子は、π型熱電変換セルが直列接続と並列接続の両方で網目状に縦横に接続されており、断線に極めて強い構造である。フレキシブル熱電デバイスにおいて、絶縁性基材と紡績糸が相互に緩やかに結合した網目構造であることによって、紡績糸の切断による出力低下を抑制する効果が得られる。 In order to achieve the above object, in the functional element of the present invention, a plurality of series structures of π-type thermoelectric conversion cells using a temperature difference in the thickness direction of the insulating base material are arranged in parallel, and p-type and n-type are switched. This element is a device having a topology in which the stages having the same potential during power generation are electrically connected. The insulating base material is in the form of a sheet or a strip having heat insulating properties and flexibility, and has a base material strength capable of maintaining the shape of the base material alone in the use environment. In the element, n-type spun yarn and p-type spun yarn made of conductive fibrous material having heat insulation properties are sewn alternately and in parallel to the insulating base material, and the front and back surfaces of the insulating base material are alternately placed. Are electrically connected to each other when penetrating them. Then, the insulating base material and the spun yarn are loosely bonded to each other, and the π-type thermoelectric conversion cell is connected in a vertical and horizontal form as an electric circuit in both series connection and parallel connection, increasing the resistance of the element to disconnection. . The functional element of the present invention has a structure that is extremely resistant to disconnection, in which π-type thermoelectric conversion cells are connected vertically and horizontally in a mesh shape in both series connection and parallel connection. In the flexible thermoelectric device, the network structure in which the insulating base material and the spun yarn are loosely coupled to each other can provide an effect of suppressing a decrease in output due to the spun yarn being cut.
　上記構成の機能性素子によれば、導電性繊維状物質から成るｎ型紡績糸とｐ型紡績糸が、絶縁性基材の表面と裏面を交互に貫通するように縫い込まれることで、π型熱電変換素子のセル直列構造を形成し、絶縁性材料の厚さによって、温度差方向に対する素子の厚み制御ができるため、表と裏で十分な温度差をつけることができ、効率の低下がないフレキシブル熱電変換素子を提供することができる。
　本発明の機能性素子における導電性繊維状物質の長手方向の熱伝導率が、１０Ｗ／ｍＫ未満に抑制されていることが好ましい。より好ましくは、導電性繊維状物質の長手方向の熱伝導率が、１Ｗ／ｍＫ未満、更に好ましくは、０．１Ｗ／ｍＫ未満に抑制されている。導電性繊維状物質の長手方向の熱伝導率を抑制することにより、本発明の機能性素子の断熱性を持たせる。本発明の機能性素子では、上述の通り、絶縁性材料の厚さによって、温度差方向に対する素子の厚み制御を行い、絶縁性材料の表と裏で十分な温度差をつける。絶縁性材料の表と裏の間には、導電性繊維状物質が貫通することになるので、導電性繊維状物質の径方向（横断方向）ではなく、長手方向の熱伝導率を抑制することにより、本発明の機能性素子の断熱性が向上する。
　導電性繊維状物質が断熱性を有することにより、機能性素子のフレキシブル熱電デバイス全体が断熱性にでき、導電性繊維状物質の断熱性を高めることによって、全体の断熱性能を向上することができる。
　本発明の機能性素子を用いるフレキシブル熱電デバイスが想定している使用温度（高温側）は、３５（体温）～１００℃程度までの場合には、低温側の冷却として、自然空冷で対応可能である。
　なお、導電性繊維状物質を横断する方向より長手方向のほうが際だって熱伝導率が高いと推察する。特に、カーボンナノチューブ（ＣＮＴ）の場合はその比が数十倍～数百倍に達すると推察できる。 According to the functional element having the above-described configuration, the n-type spun yarn and the p-type spun yarn made of the conductive fibrous substance are sewn so as to alternately penetrate the front surface and the back surface of the insulating base material. A cell series structure of type thermoelectric conversion elements is formed, and the thickness of the element can be controlled with respect to the direction of temperature difference depending on the thickness of the insulating material. A flexible thermoelectric conversion element can be provided.
It is preferable that the thermal conductivity in the longitudinal direction of the conductive fibrous substance in the functional element of the present invention is suppressed to less than 10 W / mK. More preferably, the thermal conductivity in the longitudinal direction of the conductive fibrous substance is suppressed to less than 1 W / mK, and more preferably less than 0.1 W / mK. By suppressing the thermal conductivity in the longitudinal direction of the conductive fibrous substance, the functional element of the present invention has heat insulation. In the functional element of the present invention, as described above, the thickness of the element is controlled in the temperature difference direction according to the thickness of the insulating material, and a sufficient temperature difference is provided between the front and back of the insulating material. Since the conductive fibrous substance penetrates between the front and back of the insulating material, the thermal conductivity in the longitudinal direction is suppressed rather than the radial direction (transverse direction) of the conductive fibrous substance. Thereby, the heat insulation of the functional element of the present invention is improved.
When the conductive fibrous material has heat insulating properties, the entire flexible thermoelectric device of the functional element can be made heat insulating, and by improving the heat insulating properties of the conductive fibrous material, the overall heat insulating performance can be improved. .
When the flexible thermoelectric device using the functional element of the present invention assumes a use temperature (high temperature side) of about 35 (body temperature) to about 100 ° C., it can cope with natural air cooling as cooling on the low temperature side. is there.
It is assumed that the thermal conductivity is markedly higher in the longitudinal direction than in the direction crossing the conductive fibrous material. In particular, in the case of carbon nanotubes (CNT), it can be inferred that the ratio reaches several tens to several hundred times.
　本発明の機能性素子は、ｎ型紡績糸とｐ型紡績糸が、それぞれ絶縁性基材の表面と裏面を交互に貫通する際に糸を交差させられ、少なくとも１回捻じられ接合されたことが好ましい。 In the functional element of the present invention, when the n-type spun yarn and the p-type spun yarn alternately penetrate the front and back surfaces of the insulating base material, the yarns are crossed and twisted and joined at least once. Is preferred.
　本発明の機能性素子は、ｎ型紡績糸とｐ型紡績糸が、それぞれ絶縁性基材の表面と裏面を交互に貫通する際に糸を交差させられ、交点に導電性ペーストによる電気的接続の補強が設けられたことが好ましい。 The functional element of the present invention is such that when the n-type spun yarn and the p-type spun yarn pass through the front and back surfaces of the insulating base material alternately, the yarn is crossed, and the electrical connection by the conductive paste is made at the intersection It is preferable that the reinforcement is provided.
　本発明の機能性素子は、ｎ型紡績糸とｐ型紡績糸が、それぞれ絶縁性基材の表面と裏面を交互に貫通する際に糸を交差あるいは接触させられ、交点あるいは接点が接着されたことが好ましい。 In the functional element of the present invention, when the n-type spun yarn and the p-type spun yarn alternately pass through the front and back surfaces of the insulating base material, the yarn crosses or is brought into contact with each other, and the intersection or contact is adhered. It is preferable.
　本発明の機能性素子は、ｎ型紡績糸とｐ型紡績糸が、絶縁性基材の厚み方向に対して斜めに貫通し、絶縁性基材の表面と裏面にそれぞれ露出される部分を増減させたことが好ましい。 In the functional element of the present invention, the n-type spun yarn and the p-type spun yarn penetrate obliquely with respect to the thickness direction of the insulating base material, and increase or decrease the portions exposed on the front and back surfaces of the insulating base material, respectively. It is preferable to have made it.
　本発明の機能性素子は、露出部での熱抵抗を小さくするために、ｎ型紡績糸とｐ型紡績糸が帯状、又は、ｎ型紡績糸とｐ型紡績糸の断面が多角形もしくは楕円形であることが好ましい。
　紡績糸の断面を、例えば、長方形や長楕円形あるいは星形など比表面積が大きい形状にすることにより、露出部での熱抵抗を小さくできる。 In the functional element of the present invention, the n-type spun yarn and the p-type spun yarn are band-shaped, or the cross-section of the n-type spun yarn and the p-type spun yarn is polygonal or elliptical in order to reduce the thermal resistance at the exposed portion. The shape is preferred.
By making the cross section of the spun yarn a shape having a large specific surface area such as a rectangle, an ellipse, or a star, for example, the thermal resistance at the exposed portion can be reduced.
　本発明の機能性素子において、絶縁性基材は、柔軟性と断熱性を有することが好ましく、具体的には、布又は紙、あるいは、発泡ポリマー、エラストマー、綿状凝集体及びゲル状凝集体から選択される素材を板状あるいはシート状に加工したものの何れかを好適に用いることができる。ここで、布とは、多数の繊維を薄く広い板状に加工したものであり、織物、編み物（メリヤス生地）、レース、フェルト、不織布、絹織物、毛織物が含まれる。 In the functional element of the present invention, the insulating base material preferably has flexibility and heat insulating properties, specifically, cloth or paper, or foamed polymer, elastomer, cotton-like aggregate and gel-like aggregate. Any of those obtained by processing a material selected from the above into a plate shape or a sheet shape can be suitably used. Here, the cloth is a product obtained by processing a large number of fibers into a thin and wide plate, and includes woven fabric, knitted fabric (knitted fabric), lace, felt, non-woven fabric, silk fabric, and wool fabric.
　本発明の機能性素子において、絶縁性基材は、縫製されたものであり、縫製される際に、ｎ型紡績糸とｐ型紡績糸が、同時に縫製されたことが好ましく、より好ましくは、π型熱電変換セルの厚みと実質的同一の径を有する縦糸と横糸を用いて縫製されたことである。 In the functional element of the present invention, the insulating base material is sewn, and it is preferable that the n-type spun yarn and the p-type spun yarn are sewn at the same time, and more preferably, That is, sewing was performed using warp and weft having substantially the same diameter as the thickness of the π-type thermoelectric conversion cell.
　ここで、導電性繊維状物質から成る紡績糸は、カーボンナノチューブ（ＣＮＴ）、カーボンナノファイバー（ＣＮＦ）、グラフェン（Graphene）、グラフェンナノリボン（Graphene Nanoribbon）、フラーレンナノウィスカー（Fullerene Nano Whisker）及び無機半導体ウィスカー(Whisker)の群から選択される１種以上の導電性ナノファイバーと、ポリマー、デンドリマー、ポリペプチド、タンパク質の群から選択される１種以上を主成分とする絶縁性材料もしくは導電性材料との複合材料から成るものを用いることができる。
　グラフェンナノリボンは、例えば、文献（H.Sakaguchi et al., "Width-Controlled Sub-Nanometer Graphene Nanoribbon Films Synthesized by Radical-Polymerized Chemical Vapor Deposition", Advanced Materials, Volume 26, Issue 24, pp.4134-4138, 2014）に作製方法や物性が開示されている。
　フラーレンナノウィスカーは、例えば、文献（宮澤薫一, ”フラーレンナノウィスカーの合成と性質”, 表面科学 Vol. 28, No. 1, pp. 34-39, 2007）に作製方法や物性が開示されている。 Here, the spun yarn made of conductive fibrous materials includes carbon nanotubes (CNT), carbon nanofibers (CNF), graphene, graphene nanoribbons, fullerene nano whisker, and inorganic semiconductors. One or more conductive nanofibers selected from the group of Whisker, and an insulating or conductive material mainly composed of one or more selected from the group of polymers, dendrimers, polypeptides and proteins; A material made of a composite material of
Graphene nanoribbons are described, for example, in the literature (H. Sakaguchi et al., “Width-Controlled Sub-Nanometer Graphene Nanoribbon Films Synthesized by Radical-Polymerized Chemical Vapor Deposition”, Advanced Materials, Volume 26, Issue 24, pp. 4134-4138, 2014) discloses production methods and physical properties.
Fullerene nanowhiskers, for example, have been disclosed in the literature (Junichi Miyazawa, “Synthesis and Properties of Fullerene Nanowhiskers”, Surface Science Vol. 28, No. 1, pp. 34-39, 2007) and their physical properties. Yes.
　また、導電性繊維状物質から成る紡績糸は、０．１～１００μｍの径のカーボンナノチューブ（ＣＮＴ）から成る繊維を複数撚り合せた撚糸（以下「ＣＮＴ紡績糸」という）を好適に用いることができる。
　ＣＮＴ１本の直径は、１～２ｎｍであり、ＣＮＴを繊維にする場合に最も細いものとして１０ｎｍ程度まであり得るが、機械的強度の観点から、少なくとも０．１μｍ以上の径のＣＮＴ紡績糸を用いる。また、多く撚り合せることにより１００μｍ以上の径のＣＮＴ紡績糸も実現可能であるが、絶縁性基材の表面と裏面に交互に縫い込む際の作業容易性が要求されるため、１００μｍ以下の径のＣＮＴ紡績糸を用いる。 As the spun yarn made of a conductive fibrous material, a twisted yarn (hereinafter referred to as “CNT spun yarn”) in which a plurality of fibers made of carbon nanotubes (CNT) having a diameter of 0.1 to 100 μm are twisted is preferably used. it can.
The diameter of one CNT is 1 to 2 nm, and may be up to about 10 nm as the thinnest when CNT is used as a fiber. From the viewpoint of mechanical strength, a CNT spun yarn having a diameter of at least 0.1 μm or more is used. . In addition, a CNT spun yarn having a diameter of 100 μm or more can be realized by twisting many times, but since a workability when sewing alternately on the front surface and the back surface of the insulating base material is required, a diameter of 100 μm or less is required. CNT spun yarn is used.
　ＣＮＴやその複合材料は、ＣＮＴの柔軟性や高いアスペクト比を生かすことによって、糸状に形成することができる。ＣＮＴ紡績糸を用いることにより、複雑な形状に加工した基板を使用することなく３次元構造デバイスを作製することができ、温度差方向に対するデバイスの長さも自由に制御することが可能となる。さらに、ＣＮＴの配向が長手方向にそろうことによる導電率やゼーベック係数の向上も見込まれる。また、紡績糸の形状を活かすことにより、服に直接縫い付けるといったテクスタイルエレクトロニクスの素材として幅広い応用が期待できる。
　なお、ＣＮＴから成る繊維は、ＣＮＴとＣＮＴの接合部に籠状タンパク質が挿入されることが好ましい。ＣＮＴとＣＮＴの接合部に籠状タンパク質が挿入されることにより、接合部の絶縁性のシェル部によって局所的なフォノン（格子振動）反射が生じ、熱電変換材料全体としての熱伝導率が低くなり、断熱性の基材と組み合わせることによって熱電変換効率をさらに向上させることができる。さらに、籠状タンパク質の内部に無機半導体粒子を内包させることで、接合部において電子あるいはホールを選択的にトンネル輸送することができ、導電率とゼーベック係数を向上させることができる。 CNT and composite materials thereof can be formed into a thread shape by taking advantage of the flexibility and high aspect ratio of CNT. By using the CNT spun yarn, a three-dimensional structure device can be manufactured without using a substrate processed into a complicated shape, and the length of the device with respect to the temperature difference direction can be freely controlled. Furthermore, it is expected that the conductivity and Seebeck coefficient will be improved due to the alignment of the CNTs in the longitudinal direction. In addition, by utilizing the shape of the spun yarn, a wide range of applications can be expected as a material for textile electronics such as sewing directly on clothes.
In addition, it is preferable that the cocoon protein is inserted in the joint part of CNT with the fiber which consists of CNT. By inserting rod-like protein into the junction of CNT and CNT, local phonon (lattice vibration) reflection occurs due to the insulating shell portion of the junction, and the thermal conductivity of the entire thermoelectric conversion material is lowered. The thermoelectric conversion efficiency can be further improved by combining with a heat insulating base material. Furthermore, by encapsulating inorganic semiconductor particles in the basket-like protein, electrons or holes can be selectively tunnel-transported at the junction, and the conductivity and Seebeck coefficient can be improved.
　次に、本発明の機能性素子の製造方法について説明する。
　本発明の機能性素子の製造方法は、上述した機能性素子の製造方法であって、下記のステップ１），２）を繰り返すことにより、波縫いの方向と直交する方向に電流経路が形成され、該電流経路に沿ってπ型構造直列接続が形成させる。
（ステップ１）
　ｎ型紡績糸とｐ型紡績糸の一方を第１紡績糸、他方を第２紡績糸とし、絶縁基材の表面と裏面の一方を第１面、他方を第２面として、第１紡績糸が絶縁性基材に直線状に波縫いされている状態で、波縫いされた第１紡績糸に並行に隣接して第２紡績糸を波縫いする際に、第１面で一工程前に縫った第１紡績糸の第１面に露出している部分を交差させ、少なくとも１回捻じった後に縫う。
（ステップ２）
　次に、波縫いされた第２紡績糸に並行に隣接して第１紡績糸を波縫いする際に、第２面で一工程前に縫った第２紡績糸の第２面に露出している部分を交差させ、少なくとも１回捻じった後に縫う。 Next, the manufacturing method of the functional element of this invention is demonstrated.
The functional element manufacturing method of the present invention is the above-described functional element manufacturing method, and a current path is formed in a direction orthogonal to the direction of wave stitching by repeating the following steps 1) and 2). A π-type structure series connection is formed along the current path.
(Step 1)
One of the n-type spun yarn and the p-type spun yarn is the first spun yarn, the other is the second spun yarn, one of the front and back surfaces of the insulating substrate is the first surface, and the other is the second surface. When the second spun yarn is wave-sewn adjacent to the first spun yarn that has been wave-stitched in parallel with the insulating base material, The portions exposed on the first surface of the first spun yarn that has been sewn are crossed, twisted at least once, and then sewn.
(Step 2)
Next, when the first spun yarn is wave-sewn adjacently in parallel with the second spun yarn that has been wave-stitched, the second surface is exposed to the second surface of the second spun yarn that has been sewn one step before. After crossing, twist at least once and sew.
　ｎ型紡績糸とｐ型紡績糸のそれぞれを、電気的および熱的に絶縁性を有する布状の基材に縫い込むだけで、単一の熱電変換セルだけにとどまらず、熱電変換セルを多数直列接続する構造を簡単に形成することができる。このような素子構造によって、十分な厚みを持ったフレキシブル熱電デバイスを作製することが容易となり、大気への放熱に制限されがちなフレキシブル熱電デバイスの応用（人体に貼り付ける、建造物に作り付ける等）において、素子の両面間に十分な温度差を得ることが容易で、高い変換効率が得られるようになる。
　衣服や車のシートの表皮などに用いる場合に適した１ｍｍ程度の厚みの素子から、建築用断熱材料に用いるための１０ｃｍ程度の厚みの素子までスケーラブルに用いることができる熱電デバイスの作製方法であり、幅広い用途に用いることができる。 By simply sewing each n-type spun yarn and p-type spun yarn into an electrically and thermally insulating cloth-like substrate, not only a single thermoelectric conversion cell, but many thermoelectric conversion cells A structure for serial connection can be easily formed. Such an element structure makes it easy to produce flexible thermoelectric devices with sufficient thickness, and applications of flexible thermoelectric devices that tend to be limited to heat dissipation to the atmosphere (such as pasting on the human body, building on buildings, etc.) ), It is easy to obtain a sufficient temperature difference between both surfaces of the element, and high conversion efficiency can be obtained.
It is a method for producing a thermoelectric device that can be used in a scalable manner from an element having a thickness of about 1 mm suitable for use in the skin of clothes or a car seat to an element having a thickness of about 10 cm for use as a heat insulating material for buildings. Can be used in a wide range of applications.
　本発明の機能性素子によれば、温度差を得るために十分な厚みがある断熱性のフレキシブル熱電デバイスを提供できるといった効果を有する。 The functional element of the present invention has an effect that it is possible to provide a heat-insulating flexible thermoelectric device having a sufficient thickness to obtain a temperature difference.
厚み方向の温度差を利用するπ型熱電変換セルの直列構造の説明図Explanatory drawing of series structure of π-type thermoelectric conversion cell using temperature difference in thickness direction 従来のπ型熱電変換セルの直列構造の接続トポロジーの説明図Explanatory diagram of connection topology of conventional series structure of π-type thermoelectric conversion cell π型熱電変換セルが直列接続と並列接続の両方で網目状に縦横に接合された本発明の機能性素子の接続トポロジーの説明図Explanatory diagram of the connection topology of the functional element of the present invention in which π-type thermoelectric conversion cells are joined vertically and horizontally in a mesh shape in both series connection and parallel connection 本発明の機能性素子の模式図１Schematic diagram of functional element of the present invention 1 本発明の機能性素子の模式図２Schematic diagram 2 of the functional element of the present invention 本発明の機能性素子におけるπ型熱電変換セルの説明図Explanatory drawing of the pi-type thermoelectric conversion cell in the functional element of the present invention 実施例１の機能性素子の模式図Schematic diagram of functional element of Example 1 ＣＮＴ紡績糸の作製方法の説明図Explanatory drawing of the production method of CNT spun yarn 機能性素子の作製方法の説明図１Description of a method for manufacturing a functional element FIG. 機能性素子の作製方法の説明図２Description of a method for manufacturing a functional element FIG. 機能性素子の作製方法の説明図３FIG. 3 is a diagram illustrating a method for manufacturing a functional element. ＰＥＩを用いてＣＮＴ紡績糸のキャリアドーピングを行った場合の浸漬時間と導電率及びゼーベック係数の相関グラフCorrelation graph of immersion time, conductivity and Seebeck coefficient when carrier doping of CNT spun yarn using PEI 機能性素子の熱電特性グラフThermoelectric characteristics graph of functional elements 機能性素子の作製方法のフロー図Flow chart of functional element manufacturing method 機能性素子の一部断線による影響についての説明図Explanatory diagram about the effect of partial disconnection of functional elements 実施例３の機能性素子の模式図Schematic diagram of functional device of Example 3 実施例３の機能性素子の熱電出力特性グラフThermoelectric output characteristic graph of the functional element of Example 3 実施例３の機能性素子における断線箇所の説明図Explanatory drawing of the disconnection location in the functional element of Example 3 シミュレーションに用いた機能性素子の等価回路モデルEquivalent circuit model of functional element used for simulation 切断確率の変化に伴う実施例３の機能性素子の出力の変化を示すグラフThe graph which shows the change of the output of the functional element of Example 3 accompanying the change of a cutting probability.
　以下、本発明の実施形態の一例を、図面を参照しながら詳細に説明していく。なお、本発明の範囲は、以下の実施例や図示例に限定されるものではなく、幾多の変更及び変形が可能である。 Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings. The scope of the present invention is not limited to the following examples and illustrated examples, and many changes and modifications can be made.
　厚み方向の温度差を利用するπ型熱電変換セルの直列構造について、図１を参照して説明する。なお、この図では、従来型の熱電変換素子において多くの場合に用いられているｎ型半導体部とｐ型半導体部を接続する金属配線を、単純化のために省略している。
　π型構造熱電変換セルは、ｐ型半導体部とｎ型半導体部から構成され、各セルが直列接続されて熱電変換素子になる。π型熱電変換セルでは、熱電変換素子の表面と裏面に温度差が生じると、ゼーベック効果によって起電力が発生する。そのため、熱電変換素子は片面を加温し（高温側）、他方の面を冷却（低温側）することにより、熱電変換素子に温度差が生じて発電する。 A series structure of π-type thermoelectric conversion cells using a temperature difference in the thickness direction will be described with reference to FIG. In this figure, the metal wiring connecting the n-type semiconductor portion and the p-type semiconductor portion, which is often used in conventional thermoelectric conversion elements, is omitted for the sake of simplicity.
The π-type structured thermoelectric conversion cell is composed of a p-type semiconductor portion and an n-type semiconductor portion, and each cell is connected in series to become a thermoelectric conversion element. In a π-type thermoelectric conversion cell, an electromotive force is generated due to the Seebeck effect when a temperature difference occurs between the front surface and the back surface of the thermoelectric conversion element. Therefore, the thermoelectric conversion element heats one side (high temperature side) and cools the other side (low temperature side) to generate a temperature difference in the thermoelectric conversion element.
　図２（１）は、５個のπ型熱電変換セル（π型熱電対１～５）の直列構造の接続トポロジーを示している。直列構造の両端には、それぞれ電極１，２が形成されている。π型熱電対１～５は、図１のように、それぞれ厚み方向の温度差を利用して発電する。π型熱電対１に生じた起電力によって、電極１の電位（Ｖ０）からπ型熱電対１の端部の電位はＶ１になる。同様に、π型熱電対２に生じた起電力によって、π型熱電対２の端部の電位はＶ２になる。同様に、π型熱電対３に生じた起電力によって、π型熱電対３の端部の電位はＶ３になる。そして、π型熱電対４に生じた起電力、π型熱電対５に生じた起電力によって、電極２の電位はＶ５になる。
　また、図２（２）は、５個のπ型熱電変換セルの直列構造を１ブロックとして、５ブロックが並列に接続された接続トポロジーを示している。 FIG. 2 (1) shows a connection topology of a series structure of five π-type thermoelectric conversion cells (π-type thermocouples 1 to 5). Electrodes 1 and 2 are formed at both ends of the series structure, respectively. As shown in FIG. 1, each of the π-type thermocouples 1 to 5 generates power using a temperature difference in the thickness direction. Due to the electromotive force generated in the π-type thermocouple 1, the potential at the end of the π-type thermocouple 1 becomes V 1 from the potential (V 0 ) of the electrode 1. Similarly, due to the electromotive force generated in the π-type thermocouple 2, the potential at the end of the π-type thermocouple 2 becomes V2. Similarly, due to the electromotive force generated in the π-type thermocouple 3, the potential at the end of the π-type thermocouple 3 becomes V3. The potential of the electrode 2 becomes V 5 due to the electromotive force generated in the π-type thermocouple 4 and the electromotive force generated in the π-type thermocouple 5 .
FIG. 2 (2) shows a connection topology in which five blocks are connected in parallel with a series structure of five π-type thermoelectric conversion cells as one block.
　一方、図３は、本発明の機能性素子の接続トポロジーを示している。図３に示すように、本発明の機能性素子は、ｐ型とｎ型が切り換わる部位で、同電位の段間が接続されるトポロジーを有している。図３において、点線部分だけをみると、経路中ｎ型のみまたはｐ型のみが接続されている。 On the other hand, FIG. 3 shows the connection topology of the functional element of the present invention. As shown in FIG. 3, the functional element of the present invention has a topology in which stages at the same potential are connected at a portion where p-type and n-type are switched. In FIG. 3, when only the dotted line portion is viewed, only n-type or p-type is connected in the path.
　図３に示す接続トポロジーと等価な構造を図４および図５に示す。
　図に示すように、電極１から電極２へ向かう電流経路に沿ってπ型熱電変換セルが直列接続されている。また、π型熱電変換セルの半セル毎に並列接続されている。これにより、π型熱電変換セルが直列接続と並列接続の両方で網目状に縦横に接続されている。
　図４において、点線部分の部分がそれぞれ１個のπ型熱電変換セルを形成している。
　また、電流経路の取り方を変えると、図５において、点線部分の部分がそれぞれ１個のπ型熱電変換セルを示している。トポロジー的には図３と図４あるいは図５は等価である。 A structure equivalent to the connection topology shown in FIG. 3 is shown in FIGS.
As shown in the figure, π-type thermoelectric conversion cells are connected in series along a current path from the electrode 1 to the electrode 2. Further, the half-cells of the π-type thermoelectric conversion cells are connected in parallel. As a result, the π-type thermoelectric conversion cells are connected vertically and horizontally in a mesh pattern in both series connection and parallel connection.
In FIG. 4, each dotted line portion forms one π-type thermoelectric conversion cell.
Further, when the way of taking the current path is changed, in FIG. 5, each dotted line portion indicates one π-type thermoelectric conversion cell. 3 and 4 or 5 are equivalent in terms of topology.
　本発明の機能性素子におけるπ型熱電変換セルについて、図６を参照して説明する。
　図４あるいは図５で説明した接続から電気的接続を現すための細線を取り去り、代わりにｐ型紡績糸あるいはｎ型紡績糸を想定して、それらを蛇行して接続させると図６となる。図６において、実線で示された部分が表面側、点線で示された部分が裏面側になるように３次元構造を形成すると、長方形で囲まれた部分がそれぞれ１個のπ型熱電変換セルとなっている。すなわち、トポロジー的には図３から図４に至るまで、すべて等価である。
　図６に描かれた長方形および符号Ａ～Ｃは、この素子においてセル直列接続と見なすことができる電流経路の例を示すためのものである。符号Ａで示す領域は、ｐ型紡績糸とｎ型紡績糸の一つの交点を直線的につなぐｐ型紡績糸辺とｎ型紡績糸辺の組を１つのπ型セルと見なす場合が描かれている。図の下から左上に２セル分進み、次に右上に１セル分進むように経路をたどると、３セルの直列接続と見なすことができる。また、符号Ｂで示す領域は、ｐ型紡績糸とｎ型紡績糸の一つの交点を屈曲してつなぐｐ型紡績糸辺とｎ型紡績糸辺の組を一つのπ型セルと見なす場合が描かれている。図の下から糸上をジグザグに進むように経路をたどると、３セルの直列接続と見なすことができる。符号Ｃで示す領域はπ型セルのとりかたとして符号Ａのときと符号Ｂのときのものが混在する場合が描かれている。屈曲してつながれたπ型セルをつないで下から２セル進み、そこから右上に直線的につながれたπ型セルを１セル進むように経路をたどると、３セルの直列接続と見なすことができる。
　このように、本発明の機能素子では、どの交点を見ても２つのｐ型紡績糸辺と２つのｎ型紡績糸辺の任意の組み合わせによる４種のπ型セルが定義でき、発電時の電位が単調に変化してゆく方向に経路をたどるとき、多数の任意の直列接続経路をとることができる。このトポロジー的特徴によって、断線に対して出力特性が低下しにくいという利点を得ることができるものである。 A π-type thermoelectric conversion cell in the functional element of the present invention will be described with reference to FIG.
FIG. 6 shows a case where a thin line for showing an electrical connection is removed from the connection described with reference to FIG. 4 or 5, and instead a p-type spun yarn or an n-type spun yarn is assumed and they are meandered and connected. In FIG. 6, when the three-dimensional structure is formed so that the portion indicated by the solid line is on the front side and the portion indicated by the dotted line is on the back side, each of the portions surrounded by the rectangle is one π-type thermoelectric conversion cell. It has become. That is, the topology is equivalent from FIG. 3 to FIG.
The rectangle drawn in FIG. 6 and symbols A to C are for showing examples of current paths that can be regarded as cell series connection in this element. The area indicated by the symbol A is drawn when a combination of a p-type spun yarn side and an n-type spun yarn side that linearly connects one intersection of the p-type spun yarn and the n-type spun yarn is regarded as one π-type cell. ing. If the path is followed from the bottom to the upper left by two cells and then to the upper right by one cell, it can be regarded as a series connection of three cells. In the region indicated by symbol B, there is a case where a pair of p-type spun yarn side and n-type spun yarn side connecting one bent point of p-type spun yarn and n-type spun yarn is regarded as one π-type cell. It is drawn. If the path is traced from the bottom of the figure to the zigzag on the yarn, it can be regarded as a series connection of three cells. The area indicated by the symbol C shows a case where the case of the symbol A and the symbol B are mixed as a π-type cell. Connecting two bent π-type cells and proceeding 2 cells from the bottom, and then following the path so that the π-type cells connected linearly from the upper right to 1 cell can be regarded as a series connection of 3 cells. .
Thus, in the functional element of the present invention, at any intersection, four types of π-type cells can be defined by any combination of two p-type spun yarn sides and two n-type spun yarn sides. When following a path in a direction in which the potential changes monotonously, a number of arbitrary series connection paths can be taken. With this topological feature, it is possible to obtain an advantage that the output characteristics are hardly deteriorated against disconnection.
　図７は、本実施例の機能性素子の模式図を示している。本発明の機能性素子は、導電性ナノファイバーのｐ型紡績糸１とｎ型紡績糸２が、不織布などのシート状絶縁性基材３に縫い込まれたものであり、ｐ型紡績糸１とｎ型紡績糸２はそれぞれ絶縁性基材３の表面と裏面を波縫いされ、表面と裏面に交互に貫通する際に互いに接合されるように縫い込まれている。図７では、４本のｐ型紡績糸１と３本のｎ型紡績糸２が、それぞれ絶縁性基材の表面と裏面を交互に貫通する際に糸を交差させられ、１回捻じられ係合し接合されている。ｐ型紡績糸１とｎ型紡績糸２はそれぞれ縫い目が６本設けられている。これによりπ型熱電変換セルが直列接続と並列接続の両方で網目状に縦横に接続された構造が形成されている。図７に示す網目構造は、直列数３．５ユニット、並列数１２ユニットの構造と呼ぶことができる。
　ここで、本明細書における「網目構造素子の直列数」とは、対極の電位を結ぶ電圧降下の接続方向にπ型熱電変換セルのユニット数を数えるものであるとし、また、「網目構造素子の並列数」とは、等電位を結ぶ接続方向に熱電糸の結節点を数え、結節点が最も少ない列の結節点数の２倍とする。但し、その両端などで熱電糸のが次の段に接続されていないものがあれば、それを減ずると定義する。 FIG. 7 shows a schematic diagram of the functional element of this example. The functional element of the present invention is a p-type spun yarn 1 in which a p-type spun yarn 1 and a n-type spun yarn 2 of conductive nanofibers are sewn into a sheet-like insulating substrate 3 such as a nonwoven fabric. The n-type spun yarn 2 is sewn so as to be joined to each other when the front and back surfaces of the insulating base material 3 are wave-sewn and alternately penetrate the front and back surfaces. In FIG. 7, four p-type spun yarns 1 and three n-type spun yarns 2 are alternately twisted once when the yarns cross each other when passing through the front and back surfaces of the insulating base material alternately. Are joined together. Each of the p-type spun yarn 1 and the n-type spun yarn 2 is provided with six seams. As a result, a structure is formed in which π-type thermoelectric conversion cells are connected vertically and horizontally in a mesh pattern in both series connection and parallel connection. The network structure shown in FIG. 7 can be called a structure having 3.5 units in series and 12 units in parallel.
Here, in this specification, “the number of mesh structure elements in series” means that the number of units of the π-type thermoelectric conversion cell is counted in the connection direction of the voltage drop connecting the potentials of the counter electrodes, "The number of nodes in parallel" means that the nodal points of thermoelectric yarns are counted in the connection direction connecting the equipotentials, and twice the number of nodal points of the row with the smallest number of nodal points. However, if there is a thermoelectric yarn not connected to the next stage at both ends, it is defined as reducing it.
　π型熱電変換セルの直列構造の末端は、導電性ナノファイバーの紡績糸よりも電気抵抗が低い銅線４が用いられ、電流収穫配線とされている。銅線４は、絶縁性基材３の表面と裏面を交互に貫通するように縫い込まれ、絶縁性基材３の表面及び裏面において、ｐ型紡績糸と交差して係合している。この実施例ではｐ型紡績糸の両端のみに銅線が接続されているが、縫い目ごとに接続されていても良い。
　ｐ型紡績糸１、ｎ型紡績糸２及び銅線４が係合される箇所には、交点の電気的接続を補強するために銀ペースト５が塗布されている。なお、銀ペーストに限られず、カーボンペーストなど各種導電性ペーストであっても構わない。
　以下では、導電性ナノファイバーの紡績糸として、ＣＮＴ紡績糸について説明する。 At the end of the series structure of the π-type thermoelectric conversion cell, a copper wire 4 having a lower electrical resistance than that of the conductive nanofiber spun yarn is used, which is a current harvesting wiring. The copper wire 4 is sewn so as to alternately pass through the front surface and the back surface of the insulating base material 3, and is engaged with the p-type spun yarn on the front surface and the back surface of the insulating base material 3. In this embodiment, the copper wire is connected only to both ends of the p-type spun yarn, but may be connected to each seam.
A silver paste 5 is applied to a portion where the p-type spun yarn 1, the n-type spun yarn 2 and the copper wire 4 are engaged to reinforce the electrical connection at the intersection. In addition, it is not restricted to a silver paste, Various conductive pastes, such as a carbon paste, may be sufficient.
Hereinafter, a CNT spun yarn will be described as a spun yarn of conductive nanofibers.
＜ＣＮＴ紡績糸の作製方法＞
　ＣＮＴは、ＨｉＰＣＯ法（鉄を触媒として、一酸化炭素を炭素源として成長させる手法）を用いて作られたNanoIntegris社のものを使用した。超音波分散させ、３重量％のＳＤＳ(Sodium Dodecyl Sulfate)水溶液に分散させた。図８を参照して、ＣＮＴ紡績糸の作製方法について説明する。
　まず、ディスペンサー１２に入れたＣＮＴ分散剤１１を回転台１３に乗せた容器１４内の凝集液１５に吐出することによって、流体力学的に延伸紡糸を行った。凝集液１５は、５重量％のＰＶＡ（Polyvinyl alcohol）水溶液を用いた。回転速度は約５０ｒｐｍ、中心軸から３ｃｍ程度離れたところで水流に対し並行になるように、ディスペンサー１２のノズルの向きと位置を調整して、ＣＮＴ分散剤１１の吐出を行って紡糸状ＣＮＴ１６を作製した。その後、溶媒を純水に置換して、紡糸状ＣＮＴ１６を一方の端から引き上げ、大気中で乾燥させることにより、ＣＮＴ紡績糸を作製した。得られたＣＮＴ紡績糸の直径は１０～３０μｍ程度であった。 <Method for producing CNT spun yarn>
As the CNT, NanoIntegris manufactured by HiPCO method (a method of growing iron monoxide as a catalyst and carbon monoxide as a carbon source) was used. Ultrasonically dispersed and dispersed in a 3% by weight aqueous solution of SDS (Sodium Dodecyl Sulfate). With reference to FIG. 8, a method for producing CNT spun yarn will be described.
First, the CNT dispersant 11 placed in the dispenser 12 was ejected to the agglomerate 15 in the container 14 placed on the turntable 13, thereby performing hydrodynamic stretching spinning. The aggregating liquid 15 was a 5 wt% PVA (Polyvinyl alcohol) aqueous solution. Spinning CNT16 is produced by adjusting the direction and position of the nozzle of the dispenser 12 so that the rotation speed is approximately 50 rpm and parallel to the water flow at a distance of about 3 cm from the central axis, and discharging the CNT dispersant 11. did. Thereafter, the solvent was replaced with pure water, and the spun CNT 16 was pulled up from one end and dried in the air to prepare a CNT spun yarn. The diameter of the obtained CNT spun yarn was about 10 to 30 μm.
　得られたＣＮＴ紡績糸について熱電測定を行った。測定結果を下記表1に示す。表１には、ＣＮＴ紡績糸と同じ分散条件で作製した無配向のＣＮＴ薄膜の測定結果を比較用として示している。なお、測定は全て大気中で行った。 Thermoelectric measurement was performed on the obtained CNT spun yarn. The measurement results are shown in Table 1 below. Table 1 shows the measurement results of the non-oriented CNT thin film produced under the same dispersion conditions as the CNT spun yarn for comparison. All measurements were performed in the atmosphere.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　上記表１の結果から、ＣＮＴ紡績糸では、ＣＮＴ薄膜と比較し、導電率が減少したものの、ゼーベック係数が増加したことにより、パワーファクターはＣＮＴ薄膜と比べて２．９倍に増加した。ＣＮＴ紡績糸では、長手方向が電流方向により配向していると考えられるにも関わらず導電率は減少した結果となった。この要因として、ＰＶＡへの正孔移動によるキャリア数の減少と、紡績糸を形成する際に絶縁体であるＰＶＡがＣＮＴ間に入り込んだことによるものと推察する。また、ＣＮＴ紡績糸のゼーベック係数が大きく増加していることについては、同様に、ＰＶＡへの正孔移動と共に、ＣＮＴ間に入り込んだＰＶＡがＣＮＴ接合部でのゼーベック効果を増強している可能性がある。つまり、適切な凝集剤を選択することで、ＣＮＴのキャリアや界面を制御することが可能であり、適切な凝集剤を選択することで更なる熱電性能の向上が図れる可能性があることがわかる。また、後述のキャリアドーピングによってキャリア密度を最適化することでも、熱電性能は向上する。 From the results in Table 1 above, the CNT spun yarn showed a decrease in conductivity compared to the CNT thin film, but the power factor increased 2.9 times compared to the CNT thin film due to an increase in Seebeck coefficient. In the CNT spun yarn, although the longitudinal direction was considered to be oriented in the current direction, the conductivity decreased. This is presumed to be due to the decrease in the number of carriers due to the movement of holes to PVA, and the fact that PVA, which is an insulator, entered between the CNTs when forming the spun yarn. In addition, regarding the fact that the Seebeck coefficient of CNT spun yarn is greatly increased, the possibility that PVA that has entered between CNTs has enhanced the Seebeck effect at the CNT junction as well as the movement of holes to PVA. There is. In other words, it is possible to control the CNT carrier and interface by selecting an appropriate flocculant, and there is a possibility of further improving thermoelectric performance by selecting an appropriate flocculant. . Further, the thermoelectric performance can be improved by optimizing the carrier density by carrier doping described later.
＜ＣＮＴ紡績糸に対するキャリアドーピングについて＞
　ｎ型ドーパントとして知られているＰＥＩ(Polyethyleneimine)を用いて、ＣＮＴ紡績糸のキャリアドーピングを行った。ｎ型ドーピングは１重量％のＰＥＩ水溶液（溶媒：メタノール）に対して、ＣＮＴ紡績糸を一定時間浸すことで行った。浸漬時間と、導電率及びゼーベック係数の関係を図１２に示す。
　ＣＮＴ紡績糸をＰＥＩに浸漬して十分な時間ドーピングを行うと、ゼーベック係数がｎ型に変化しており、ＰＥＩがドナーとして機能していることがわかる。導電率の時間変化については、ドーピング当初は、ドナー分子によって電子が注入されると、ＣＮＴに本来存在するホールを打ち消し、真性に近づき導電率がいったん減少するが、ドーピングが更に進行すると電子が多数キャリアとなって導電率が増加する。
　ゼーベック係数Ｓは、下記数式１のように、電子とホールの各々の導電率の重みをもったゼーベック係数の和となる。 <About carrier doping for CNT spun yarn>
Carrier doping of CNT spun yarn was performed using PEI (Polyethyleneimine) known as an n-type dopant. The n-type doping was performed by immersing the CNT spun yarn in a 1% by weight PEI aqueous solution (solvent: methanol) for a predetermined time. FIG. 12 shows the relationship between the immersion time, the conductivity, and the Seebeck coefficient.
When the CNT spun yarn is immersed in PEI and doped for a sufficient time, the Seebeck coefficient changes to n-type, and it can be seen that PEI functions as a donor. Regarding the change in conductivity over time, at the beginning of doping, when electrons are injected by the donor molecule, the holes originally present in the CNT are canceled out, approaching the intrinsicity, and the conductivity once decreases. It becomes a carrier and conductivity increases.
The Seebeck coefficient S is a sum of Seebeck coefficients having the weights of the conductivity of each of electrons and holes, as in the following Equation 1.
Figure JPOXMLDOC01-appb-M000002
Figure JPOXMLDOC01-appb-M000002
　ここで、Ｓｅは電子のゼーベック係数、Ｓｈはホールのゼーベック係数、δｅは電子の導電率、δｈはホールの導電率である。ドーピングを行う前は、δｅ<<δｈであるため、Ｓ＝Ｓｈである。ドーピングによりホールの導電率が減少するため、電子のゼーベック効果を影響が無視できなくなり、全体のゼーベック係数が減少する。さらに、ドーピングが進むと、δｅ>>δｈとなり、Ｓ＝Ｓｅとなる。このことから、作製したＣＮＴ紡績糸は、従来のＣＮＴ薄膜と同様にドーパントによるキャリア制御が可能であることがわかる。 Here, S e is the electron Seebeck coefficient, S h is the Seebeck coefficient of the Hall, [delta] e is the electron conductivity, the [delta] h is the conductivity of the hole. Prior to doping, S = S h because δ e << δ h . Since the hole conductivity is reduced by doping, the influence of the electron Seebeck effect cannot be ignored, and the overall Seebeck coefficient is reduced. Further, as doping progresses, δ e >> δ h and S = S e . From this, it can be seen that the produced CNT spun yarn is capable of carrier control by the dopant as in the conventional CNT thin film.
　次に、機能性素子の作製方法について、図９～１１を参照して説明する。
　図９では、１本のｐ型ＣＮＴ紡績糸が絶縁性基材３に波縫いされた状態を示している。図９に示すように、絶縁性基材３には、ｐ型ＣＮＴ紡績糸１ａが絶縁性基材３の表面と裏面を交互に貫通するように、直線状に波縫いで縫い込まれている。 Next, a method for manufacturing a functional element will be described with reference to FIGS.
FIG. 9 shows a state in which one p-type CNT spun yarn is wave-sewn on the insulating base material 3. As shown in FIG. 9, in the insulating base material 3, the p-type CNT spun yarn 1a is sewn by wave stitching in a straight line so as to alternately penetrate the front surface and the back surface of the insulating base material 3. .
　図１０は、ｐ型ＣＮＴ紡績糸及びｎ型ＣＮＴ紡績糸が並列に１本ずつ縫い込まれた状態を示している。ｐ型ＣＮＴ紡績糸１ａが絶縁性基材３縫い込まれた状態で、次に、ｎ型ＣＮＴ紡績糸２ａをｐ型ＣＮＴ紡績糸１ａの横に並行に縫い込む。図４に示すように、ｎ型ＣＮＴ紡績糸２ａを縫い込む際、ｐ型ＣＮＴ紡績糸１ａを縫い込む場合と同様に、絶縁性基材３の表面と裏面を交互に貫通するように縫い込まれている。そして、ｐ型ＣＮＴ紡績糸１ａとｎ型ＣＮＴ紡績糸２ａは、絶縁性基材３の表面上に表出した箇所同士を交差させて、１回捻じらせて係合して接合させている。係合した交点には、ここでは図示しないが銀ペーストが塗布されて、電気的接続が補強されている。 FIG. 10 shows a state in which p-type CNT spun yarn and n-type CNT spun yarn are sewn one by one in parallel. Next, the n-type CNT spun yarn 2a is sewn in parallel to the p-type CNT spun yarn 1a in a state where the p-type CNT spun yarn 1a is sewn into the insulating base material 3. As shown in FIG. 4, when the n-type CNT spun yarn 2a is sewn, it is sewn so as to alternately penetrate the front and back surfaces of the insulating base material 3 in the same manner as when the p-type CNT spun yarn 1a is sewn. It is rare. Then, the p-type CNT spun yarn 1a and the n-type CNT spun yarn 2a are joined by being twisted once and engaged by joining the portions exposed on the surface of the insulating base material 3. . Although not shown here, silver paste is applied to the engaged intersections to reinforce the electrical connection.
　図１１は、ｐ型ＣＮＴ紡績糸及びｎ型ＣＮＴ紡績糸をそれぞれ４本ずつ縫い込んだ状態を示している。ｐ型ＣＮＴ紡績糸１ｂが絶縁性基材３に縫い込まれる際、図１１に示すように、ｐ型ＣＮＴ紡績糸１ａを縫い込む場合と同様に、絶縁性基材３の表面と裏面を交互に貫通するように縫い込まれている。そして、ｐ型ＣＮＴ紡績糸１ｂとｎ型ＣＮＴ紡績糸２ａは、絶縁性基材３の裏面上に表出した箇所同士を交差させて、１回捻じらせて係合させている。係合した交点には、ここでは図示しないが銀ペーストが塗布されて、電気的接続が補強されている。 FIG. 11 shows a state in which four p-type CNT spun yarns and four n-type CNT spun yarns are sewn. When the p-type CNT spun yarn 1b is sewn into the insulating base material 3, as shown in FIG. 11, the front and back surfaces of the insulating base material 3 are alternated in the same manner as when the p-type CNT spun yarn 1a is sewn. It is sewn so as to penetrate through. Then, the p-type CNT spun yarn 1b and the n-type CNT spun yarn 2a are engaged by twisting once, with the portions exposed on the back surface of the insulating base material 3 intersecting each other. Although not shown here, silver paste is applied to the engaged intersections to reinforce the electrical connection.
　次に、ｎ型ＣＮＴ紡績糸２ｂが縫い込まれる。ｎ型ＣＮＴ紡績糸２ｂの縫い込み方法については、ｎ型ＣＮＴ紡績糸２ａの縫い込み方法と同様である。また、ｐ型ＣＮＴ紡績糸１ｂとｎ型ＣＮＴ紡績糸２ｂの編み込み方法については、ｐ型ＣＮＴ紡績糸１ａとｎ型ＣＮＴ紡績糸２ａの編み込み方法と同様である。 Next, the n-type CNT spun yarn 2b is sewn. The method for sewing the n-type CNT spun yarn 2b is the same as the method for sewing the n-type CNT spun yarn 2a. The method for weaving the p-type CNT spun yarn 1b and the n-type CNT spun yarn 2b is the same as the method for weaving the p-type CNT spun yarn 1a and the n-type CNT spun yarn 2a.
　次に、ｐ型ＣＮＴ紡績糸１ｃが縫い込まれる。ｐ型ＣＮＴ紡績糸１ｃの縫い込み方法については、ｐ型ＣＮＴ紡績糸１ｂの縫い込み方法と同様である。また、ｎ型ＣＮＴ紡績糸２ｂとｐ型ＣＮＴ紡績糸１ｃの編み込み方法については、ｎ型ＣＮＴ紡績糸２ａとｐ型ＣＮＴ紡績糸１ｂの編み込み方法と同様である。 Next, the p-type CNT spun yarn 1c is sewn. The method for sewing the p-type CNT spun yarn 1c is the same as the method for sewing the p-type CNT spun yarn 1b. The method for weaving the n-type CNT spun yarn 2b and the p-type CNT spun yarn 1c is the same as the method for weaving the n-type CNT spun yarn 2a and the p-type CNT spun yarn 1b.
　次に、ｎ型ＣＮＴ紡績糸２ｃが縫い込まれる。ｎ型ＣＮＴ紡績糸２ｃの縫い込み方法については、ｎ型ＣＮＴ紡績糸（２ａ，２ｂ）の縫い込み方法と同様である。また、ｐ型ＣＮＴ紡績糸１ｃとｎ型ＣＮＴ紡績糸２ｃの編み込み方法については、ｐ型ＣＮＴ紡績糸１ａとｎ型ＣＮＴ紡績糸２ａ、又は、ｐ型ＣＮＴ紡績糸１ｂとｎ型ＣＮＴ紡績糸２ｂの編み込み方法と同様である。 Next, the n-type CNT spun yarn 2c is sewn. The method for sewing the n-type CNT spun yarn 2c is the same as the method for sewing the n-type CNT spun yarn (2a, 2b). The p-type CNT spun yarn 1c and the n-type CNT spun yarn 2c are knitted in the p-type CNT spun yarn 1a and the n-type CNT spun yarn 2a, or the p-type CNT spun yarn 1b and the n-type CNT spun yarn 2b. This is the same as the weaving method.
　次に、ｐ型ＣＮＴ紡績糸１ｄが縫い込まれる。ｐ型ＣＮＴ紡績糸１ｄの縫い込み方法については、ｐ型ＣＮＴ紡績糸（１ｂ、１ｃ）の縫い込み方法と同様である。また、ｎ型ＣＮＴ紡績糸２ｃとｐ型ＣＮＴ紡績糸１ｄの編み込み方法については、ｎ型ＣＮＴ紡績糸２ａとｐ型ＣＮＴ紡績糸１ｂ、又は、ｎ型ＣＮＴ紡績糸２ｂとｐ型ＣＮＴ紡績糸１ｃの編み込み方法と同様である。 Next, the p-type CNT spun yarn 1d is sewn. The method for sewing the p-type CNT spun yarn 1d is the same as the method for sewing the p-type CNT spun yarn (1b, 1c). The n-type CNT spun yarn 2c and the p-type CNT spun yarn 1d are knitted by the n-type CNT spun yarn 2a and the p-type CNT spun yarn 1b or the n-type CNT spun yarn 2b and the p-type CNT spun yarn 1c. This is the same as the weaving method.
　このように、ｐ型ＣＮＴ紡績糸１を縫い込む際には隣接する１工程前のｎ型ＣＮＴ紡績糸２を裏面において編み込むようにして、また、ｎ型ＣＮＴ紡績糸２を縫い込む際には隣接する１工程前のｐ型ＣＮＴ紡績糸１を裏面において編み込むようにして、絶縁性基材３に縫い込む。 As described above, when the p-type CNT spun yarn 1 is sewn, the adjacent n-type CNT spun yarn 2 before one step is knitted on the back surface, and when the n-type CNT spun yarn 2 is sewn, it is adjacent. The p-type CNT spun yarn 1 before one step is knitted into the insulating base material 3 so as to be knitted on the back surface.
　図１４は、本発明の機能性素子の作製方法のフロー図を示している。図１４に示すように、まず、ｐ型紡績糸が絶縁性基材に直線状に波縫いされる（ステップＳ０１）。次に、波縫いされたｐ型紡績糸に並行に隣接してｎ型紡績糸を波縫いする際に、表面で一工程前に縫ったｐ型紡績糸の表面に露出している部分を交差させ、１回捻じった後に縫う（ステップＳ０２）。波縫いされたｎ型紡績糸に並行に隣接してｐ型紡績糸を波縫いする際に、裏面で一工程前に縫ったｎ型紡績糸の裏面に露出している部分を交差させ、１回捻じった後に縫う（ステップＳ０３）。ステップ２，３を必要な回数だけ繰り返す（ステップＳ０４）。
　なお、図４に示すような電流収穫配線として銅などの良導体の細線を両端部に用いる場合、例えばステップＳ０１において、ｐ型紡績糸を用いる代わりに良導体細線を用い、さらに繰り返しの最終のステップＳ０３において、ｐ型紡績糸を用いる代わりに良導体細線を用いれば良い。
　繰り返しによって形成された構造は、波縫いの方向とは直交する方向が電流経路となり、その電流経路に沿ってπ型構造直列接続が形成され、波縫い方向にはそのπ型構造が半セル毎に、すなわち等電位となる点同士が横に並列接続された構造となる。 FIG. 14 shows a flowchart of a method for manufacturing a functional element of the present invention. As shown in FIG. 14, first, the p-type spun yarn is wave-stitched linearly on the insulating base material (step S01). Next, when the n-type spun yarn is wave-sewn adjacent to the wave-sewn p-type spun yarn in parallel, the portion exposed on the surface of the p-type spun yarn sewed one step before on the surface intersects. And sew after twisting once (step S02). When p-type spun yarn is wave-sewn adjacent to and parallel to the wave-stitched n-type spun yarn, the back surface of the n-type spun yarn sewed one step at the back is crossed. After being twisted, sewing is performed (step S03). Steps 2 and 3 are repeated as many times as necessary (step S04).
In the case where fine conductors such as copper are used at both ends as the current harvesting wiring as shown in FIG. 4, for example, in step S01, good conductor thin wires are used instead of p-type spun yarn, and the final step S03 is repeated. In this case, instead of using the p-type spun yarn, a good conductor fine wire may be used.
In the structure formed by repetition, the direction perpendicular to the direction of wave stitching is a current path, and a π-type structure series connection is formed along the current path. In other words, the equipotential points are laterally connected in parallel.
　ここで、本発明の機能性素子の一部断線による影響について図１５を参照して説明する。
　図１５（１）は、従来技術であるπ型構造直列構造を基本とする熱電変換素子において、面積増によって十分な発電電力量を得るために、直列接続ユニットを３組並置したものを示している。これら３組の直列接続ユニットは、素子外部において並列接続される。
　この素子において、図の×印で示された箇所で電流経路に断線が生じた場合を考える。この１カ所の断線によって、灰色に塗られた直列接続ユニット１組が完全に発電動作を停止する結果となる。
　例えば、π型セルが１０段直列接続されたユニットを１０組並置し、外部で並列接続させた大面積素子を考える。この大面積素子において、どこか１カ所で紡績糸が断線すると、合計の電気コンダクタンスが９０％（すなわち、電気抵抗は約１１０％）になり、最大発電電力量も９０％に低下する。すなわち、１０％の発電電力低下が起こる。 Here, the influence of the partial disconnection of the functional element of the present invention will be described with reference to FIG.
FIG. 15 (1) shows a conventional thermoelectric conversion element based on a π-type structure series structure in which three sets of series connection units are juxtaposed in order to obtain a sufficient amount of generated power by increasing the area. Yes. These three sets of series connection units are connected in parallel outside the element.
In this element, let us consider a case in which a break occurs in the current path at the location indicated by the cross in the figure. As a result of this disconnection at one place, one set of series connection units painted in gray completely stops the power generation operation.
For example, consider a large-area element in which 10 sets of 10 π-type cells connected in series are juxtaposed and connected externally in parallel. In this large-area element, if the spun yarn breaks at one place, the total electric conductance becomes 90% (that is, the electric resistance is about 110%), and the maximum power generation amount is also reduced to 90%. That is, a 10% reduction in generated power occurs.
　図１５（２）は、本発明の機能性素子の網目構造の熱電変換素子を示している。
　図１５（２）に示す機能性素子において、図の×印でしめされた箇所で電流経路に断線が生じた場合を考える。この1カ所の断線によって、灰色に塗られたπ型構造半セルは発電動作を停止するが、電流経路のトポロジーが網目構造となっていることから、同一のπ型構造セルに属すると見なすことができる隣接した半セルを含めて全てのセルに電流経路が確保されていることから断線した縫い目部分以外の発電動作に影響は及ばない。
　例えば、π型セル１０×１０ユニットの網目構造を持つ大面積素子を考える。総セル数は、前述の従来型直列接続による大面積素子と同じである。この大面積素子において、どこか１カ所で紡績糸が断線すると、合計の電気コンダクタンスは約９９％（すなわち、電気抵抗は約１０１％）、最大発電電力量は約９９％になる。すなわち、発電電力低下は１％に抑制される。 FIG. 15 (2) shows a thermoelectric conversion element having a network structure of functional elements of the present invention.
In the functional element shown in FIG. 15 (2), a case is considered in which a disconnection occurs in the current path at a location indicated by a cross in the figure. Due to this disconnection at one location, the π-type half-cells painted in gray cease to generate electricity, but since the topology of the current path is a network structure, they are considered to belong to the same π-type structure cell. Since current paths are secured in all cells including adjacent half-cells capable of generating power, the power generation operation other than the disconnected seam portion is not affected.
For example, consider a large-area device having a network structure of π-type cells 10 × 10 units. The total number of cells is the same as that of the large-area element by the conventional series connection described above. In this large-area element, if the spun yarn breaks at one place, the total electric conductance is about 99% (that is, the electric resistance is about 101%), and the maximum power generation amount is about 99%. That is, the decrease in generated power is suppressed to 1%.
（本発明の機能性素子の熱電特性について）
　図８に示した方法によってＣＮＴ複合材料を紡糸したｐ型紡績糸、および、それに対して図１２に示した方法によってドーピングを施したｎ型紡績糸を用い、図１１及び図１４に示した方法によって、図７に示した網目構造を有する機能性素子を作製したものの熱電特性を評価した。
　機能性素子の熱電出力特性グラフを図１３に、解放端電圧を下記表２に示す。表２から、表面と裏面との間の温度差に比例して、解放端電圧が増加していることがわかる。また、図１３に示すように、出力特性も負荷抵抗に応じて出力電力が電圧に対して放物線を描く理論どおりの特性となっている。
　この機能性素子は十分な柔軟性を有しており、曲げ、捻り、および数％程度の引っ張りに対して、素子抵抗が変化しないことが確認された。また、断熱性基材と熱伝導率が低いＣＮＴ複合材料紡績糸を用いているため、大気中において片面を手で触れるだけで温度差５～１０℃に相当する出力が得られることが確認された。 (Regarding the thermoelectric characteristics of the functional element of the present invention)
The p-type spun yarn obtained by spinning the CNT composite material by the method shown in FIG. 8 and the n-type spun yarn doped by the method shown in FIG. Thus, the thermoelectric characteristics of the functional element having the network structure shown in FIG. 7 were evaluated.
A thermoelectric output characteristic graph of the functional element is shown in FIG. From Table 2, it can be seen that the open-circuit voltage increases in proportion to the temperature difference between the front surface and the back surface. Further, as shown in FIG. 13, the output characteristics are also characteristics as shown in the theory that the output power draws a parabola with respect to the voltage according to the load resistance.
This functional element has sufficient flexibility, and it was confirmed that the element resistance did not change with respect to bending, twisting, and pulling of about several percent. In addition, it is confirmed that an output corresponding to a temperature difference of 5 to 10 ° C can be obtained by simply touching one side with the hand in the atmosphere because of the use of a heat insulating base material and a CNT composite material spun yarn having low thermal conductivity. It was.
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
　本実施例では、実施例１，２と同様の構造であって、より高性能な機能性素子について説明する。本実施例の機能性素子の構造は、図７に示す機能性素子の模式図と同様である。すなわち、本実施例の機能性素子は、図７に示すように、導電性ナノファイバーのｐ型紡績糸１とｎ型紡績糸２が、不織布などのシート状絶縁性基材３に縫い込まれたものであり、ｐ型紡績糸１とｎ型紡績糸２はそれぞれ絶縁性基材３の表面と裏面を波縫いされ、表面と裏面に交互に貫通する際に互いに接合されるように縫い込まれている。
　図７の模式図では、４本のｐ型紡績糸１と３本のｎ型紡績糸２が、それぞれ絶縁性基材の表面と裏面を交互に貫通する際に糸を交差させられ、１回捻じられ係合し接合され、ｐ型紡績糸１とｎ型紡績糸２はそれぞれ縫い目が６本設けられ、これによりπ型熱電変換セルが直列接続と並列接続の両方で網目状に縦横に接続された構造（直列数３．５ユニット、並列数１２ユニットの構造）が形成されているが、本実施例では、図１６の模式図に示すように、３本のｐ型紡績糸１と２本のｎ型紡績糸２が、それぞれ絶縁性基材の表面と裏面を交互に貫通する際に糸を交差させられ、１回捻じられ係合し接合され、ｐ型紡績糸１とｎ型紡績糸２はそれぞれ縫い目が７本設けられ、これによりπ型熱電変換セルが直列接続と並列接続の両方で網目状に縦横に接続された構造（直列数２．５ユニット、並列数１４ユニット）が形成されている。 In this embodiment, a functional element having the same structure as that of Embodiments 1 and 2 and having higher performance will be described. The structure of the functional element of this example is the same as the schematic diagram of the functional element shown in FIG. That is, in the functional element of this example, as shown in FIG. 7, the p-type spun yarn 1 and the n-type spun yarn 2 of conductive nanofibers are sewn into a sheet-like insulating substrate 3 such as a nonwoven fabric. The p-type spun yarn 1 and the n-type spun yarn 2 are sewn so that the front and back surfaces of the insulating base material 3 are corrugated and joined together when alternately penetrating the front and back surfaces. It is rare.
In the schematic diagram of FIG. 7, four p-type spun yarns 1 and three n-type spun yarns 2 cross the front and back surfaces of the insulating base material alternately, and the yarns are crossed once. The p-type spun yarn 1 and the n-type spun yarn 2 are each provided with six stitches so that the π-type thermoelectric conversion cells can be connected vertically and horizontally in both a series connection and a parallel connection. In this embodiment, as shown in the schematic diagram of FIG. 16, three p-type spun yarns 1 and 2 are formed. When the n-type spun yarn 2 passes through the front and back surfaces of the insulating base material alternately, the yarns are crossed, twisted once, engaged and joined, and the p-type spun yarn 1 and the n-type spun yarn are joined. Each thread 2 is provided with seven seams, so that the π-type thermoelectric conversion cells are vertically connected in a mesh shape in both series connection and parallel connection. A horizontally connected structure (2.5 units in series, 14 units in parallel) is formed.
　また、実施例１，２ではｐ型紡績糸の両端のみ、すなわち、π型熱電変換セルの直列構造の末端のみに銅線４が接続されているが、本実施例の機能性素子では、縫い目ごとに銅線が接続される構造とした。すなわち、銅線４は、絶縁性基材３の表面と裏面を交互に貫通するように縫い込まれ、絶縁性基材３の表面及び裏面において、縫い目ごとにｐ型紡績糸と交差して係合され、縫い目ごとにπ型熱電変換セルに接続されるようにした。すなわち、銅線、ｐ型紡績糸、ｎ型紡績糸、ｐ型紡績糸、ｎ型紡績糸、ｐ型紡績糸、銅線という順番で縫い込み、銅線とｐ型紡績糸も縫い目ごとに交差させたものとなっている。
　ｐ型紡績糸１、ｎ型紡績糸２及び銅線４が係合される箇所には、交点の電気的接続を補強するために銀ペースト５が塗布された。 In Examples 1 and 2, the copper wire 4 is connected only to both ends of the p-type spun yarn, that is, only to the end of the series structure of the π-type thermoelectric conversion cell. It was set as the structure where a copper wire is connected for every. That is, the copper wire 4 is sewn so as to alternately penetrate the front surface and the back surface of the insulating base material 3, and on the front surface and the back surface of the insulating base material 3, it intersects with the p-type spun yarn for each stitch. And connected to a π-type thermoelectric conversion cell for each stitch. In other words, copper wire, p-type spun yarn, n-type spun yarn, p-type spun yarn, n-type spun yarn, p-type spun yarn, copper wire are sewn in this order, and the copper wire and p-type spun yarn intersect at each stitch. It has been made to.
A silver paste 5 was applied to the portion where the p-type spun yarn 1, the n-type spun yarn 2 and the copper wire 4 were engaged in order to reinforce the electrical connection at the intersection.
＜ＣＮＴ紡績糸の作製方法＞
　ＣＮＴ紡績糸の作製方法は、実施例１と同様であるが、使用したＣＮＴおよび凝集液が異なり、作製したＣＮＴ紡績糸の径に違いがある。実施例１と同様に、図８を参照して説明する。
　ＣＮＴは、ｅＤＩＰＳ法（enhanced Direct Injection Pyrolytic Synthesis method）を用いて作られたものを使用した。超音波分散させ、３重量％のＳＤＳ（Sodium Dodecyl Sulfate）水溶液に分散させ、さらにバインダーとして０．０１重量％のポリエチレングリコールを添加した。図８に示すように、ディスペンサー１２に入れたＣＮＴ分散剤１１を回転台１３に乗せた容器１４内の凝集液１５に吐出することによって、流体力学的に延伸紡糸を行った。凝集液１５は、純メタノールを用いた。回転速度は約５０ｒｐｍ、中心軸から３ｃｍ程度離れたところで水流に対し並行になるように、ディスペンサー１２のノズルの向きと位置を調整して、ＣＮＴ分散剤１１の吐出を行って紡糸状ＣＮＴ１６を作製した。その後、溶媒を純水に置換して、紡糸状ＣＮＴ１６を一方の端から引き上げ、大気中で乾燥させることにより、ＣＮＴ紡績糸を作製した。得られたＣＮＴ紡績糸の直径は３０～５０μｍ程度であり、実施例１のＣＮＴ紡績糸（直径１０～３０μｍ程度）より太い紡績糸が作製できた。 <Method for producing CNT spun yarn>
The method for producing the CNT spun yarn is the same as in Example 1, but the CNTs used and the aggregating liquid are different, and the diameter of the produced CNT spun yarn is different. Similar to the first embodiment, description will be made with reference to FIG.
CNT used what was made using eDIPS method (enhanced Direct Injection Pyrolytic Synthesis method). Ultrasonically dispersed, dispersed in a 3% by weight aqueous solution of SDS (Sodium Dodecyl Sulfate), and further 0.01% by weight of polyethylene glycol was added as a binder. As shown in FIG. 8, the CNT dispersant 11 placed in the dispenser 12 was ejected to the agglomerate 15 in the container 14 placed on the turntable 13, thereby hydrodynamically drawing and spinning. As the aggregating liquid 15, pure methanol was used. Spinning CNT16 is produced by adjusting the direction and position of the nozzle of the dispenser 12 so that the rotation speed is approximately 50 rpm and parallel to the water flow at a distance of about 3 cm from the central axis, and discharging the CNT dispersant 11. did. Thereafter, the solvent was replaced with pure water, and the spun CNT 16 was pulled up from one end and dried in the air to prepare a CNT spun yarn. The obtained CNT spun yarn had a diameter of about 30 to 50 μm, and a spun yarn thicker than the CNT spun yarn of Example 1 (diameter of about 10 to 30 μm) could be produced.
＜ＣＮＴ紡績糸に対するキャリアドーピングについて＞
　イオン液体として知られる［ＢＭＩＭ］ＰＦ６を用いて、ＣＮＴ紡績糸のｎ型ドーピングを行った。ドーパント溶液として、［ＢＭＩＭ］ＰＦ６にＤＭＳＯ（Dimethyl sulfoxide）を体積比１０％となるように添加し、ＣＮＴ紡績糸を２４時間浸漬することでドーピングを行った。ここで、ＤＭＳＯは、［ＢＭＩＭ］ＰＦ６がＣＮＴ紡績糸へ浸透するのを補助する役割がある。浸漬後のＣＮＴ紡績糸に付着するイオン液体は、実験用コットン布で拭き取った。
　上記のｎ型ドーピングにより、本来、p型特性（ゼーベック係数；４７．８μＶ／Ｋ)であったＣＮＴ紡績糸が、ｎ型特性（ゼーベック係数；－４９．１μＶ／Ｋ)となることを確認した。 <About carrier doping for CNT spun yarn>
[BMIM] PF 6 known as an ionic liquid was used for n-type doping of CNT spun yarn. As the dopant solution, DMSO (Dimethyl sulfoxide) was added to [BMIM] PF 6 so that the volume ratio was 10%, and the CNT spun yarn was immersed for 24 hours for doping. Here, DMSO has a role to help [BMIM] PF 6 penetrate into the CNT spun yarn. The ionic liquid adhering to the CNT spun yarn after immersion was wiped off with an experimental cotton cloth.
It was confirmed that the CNT spun yarn, which originally had p-type characteristics (Seebeck coefficient; 47.8 μV / K), has n-type characteristics (Seebeck coefficient; −49.1 μV / K) by the above n-type doping. .
　上述のイオン液体によるＣＮＴ紡績糸に対するキャリアドーピングの効果の機序は現時点で断定できないものの、紡績糸に残されたイオン液体の成分分析の結果から（下記表３を参照）、以下のように推察する。
　イオン液体を用いて、ＣＮＴ紡績糸に対するキャリアドーピングを施すと、少数ではあるが一定割合で存在する乖離フッ素イオンがＣＮＴと電荷交換し、ＣＮＴに電子を供与して自身は中性となる。中性となったフッ素はフッ素ガスとして、またフッ素イオンを生みだす際に中性となったリンフッ化物分子もガスとして大気中に放出される。このような、大気への陰イオン成分（ＰＦ６）の放出のため、ＣＮＴに付着したイオン液体のイオンバランスが崩れ、負電荷の一部をＣＮＴが受け持つことでｎ型化すると推察する。
　下記表３は、イオン液体の［ＢＭＩＭ］ＰＦ６を用いてドーピングしたＣＮＴ紡績糸のＳＥＭ－ＥＤＸ元素分析結果を示している。 Although the mechanism of the effect of carrier doping on the CNT spun yarn by the ionic liquid described above cannot be determined at present, the following is inferred from the result of component analysis of the ionic liquid remaining in the spun yarn (see Table 3 below). To do.
When carrier doping is applied to the CNT spun yarn using an ionic liquid, a small number of fluorinated ions present at a constant ratio exchange with CNT, donating electrons to the CNT, and becoming neutral. Neutral fluorine is released into the atmosphere as fluorine gas, and phosphorous fluoride molecules that become neutral when fluorine ions are produced. It is assumed that due to the release of the anion component (PF 6 ) to the atmosphere, the ion balance of the ionic liquid adhering to the CNT is broken, and the CNT takes part of the negative charge and becomes n-type.
Table 3 shows the SEM-EDX elemental analysis of CNT yarns doped with [BMIM] PF 6 ionic liquids.
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000004
（機能性素子の熱電特性について）
　本実施例の機能性素子の熱電特性を評価した。本実施例の機能性素子の熱電出力特性グラフを、図１７に示す。ＣＮＴ紡績糸の作製法ならびにドーピング法の改良により、図１３と比較して直列数が少ないにもかかわらず同等の出力電圧が得られており（図１３の場合は直列数が３．５ユニットであるのに対して、図１７の場合は直列数が２．５ユニットである）、出力電力は増加していた。また、負荷抵抗に応じて出力電力が電圧に対して、放物線を描く理論どおりの特性となっていた。
　本実施例の機能性素子は十分な柔軟性を有しており、曲げ、捻り、および数％程度の引っ張りに対して、素子抵抗が変化しないことが確認された。また、断熱性基材と熱伝導率が低いＣＮＴ複合材料紡績糸を用いているため、大気中において片面を手で触れるだけで温度差５～１０℃に相当する出力が得られることが確認された。 (Thermoelectric properties of functional elements)
The thermoelectric characteristics of the functional element of this example were evaluated. A thermoelectric output characteristic graph of the functional element of this example is shown in FIG. Due to improvements in the CNT spun yarn production method and doping method, an equivalent output voltage was obtained despite the fact that the number of series was smaller compared to FIG. 13 (in the case of FIG. 13, the number of series is 3.5 units). In contrast, in the case of FIG. 17, the number of series is 2.5 units), and the output power is increased. In addition, the output power has a theoretical characteristic that draws a parabola with respect to the voltage according to the load resistance.
The functional element of this example had sufficient flexibility, and it was confirmed that the element resistance did not change with respect to bending, twisting, and pulling of about several percent. In addition, it is confirmed that an output corresponding to a temperature difference of 5 to 10 ° C can be obtained by simply touching one side with the hand in the atmosphere because of the use of a heat insulating base material and a CNT composite material spun yarn having low thermal conductivity. It was.
　本実施例の機能性素子の１カ所断線前後の熱電特性について説明する。図１８に示すように、断線箇所８の１カ所のみ切断した後の熱電特性を評価した。下記表４は、本実施例の機能性素子における１カ所切断前後の最大発電電力量を示している。下記表４から、表面と裏面との間の温度差の二乗に比例して、最大発電電力量が増加していることがわかる。素子抵抗は、切断前は２３９Ωであり、切断後は２６２Ωであった。 The thermoelectric characteristics before and after the disconnection of the functional element of this example will be described. As shown in FIG. 18, the thermoelectric characteristics after cutting only one of the disconnection points 8 were evaluated. Table 4 below shows the maximum power generation amount before and after cutting at one place in the functional element of this example. From Table 4 below, it can be seen that the maximum power generation amount is increased in proportion to the square of the temperature difference between the front surface and the back surface. The element resistance was 239Ω before cutting and 262Ω after cutting.
Figure JPOXMLDOC01-appb-T000005
Figure JPOXMLDOC01-appb-T000005
　最大発電電力量の断線による影響を評価するに当たって、本機能性素子が柔軟性と伸縮性に富むことから、付与された温度差とその素子内分布を厳密に一定にすることが困難であるという課題がある。それにより、測定値にばらつきや時間によるゆらぎが生じることから、表４の各温度における発電電力量相対値の平均を取ることによって、その影響を軽減することとした。表４の各温度における発電電力量相対値の平均は、０．９９４であり、最大出力の低下は、１カ所の断線によって０．６％程度にとどまったと判断される。これは理論的に予測された２．５％よりやや良い成績であるが、上述の誤差要因を考えると妥当な値であると判断される。
　また、測定された素子抵抗の変化から、素子コンダクタンスは０．９１２倍であり、１カ所の断線による低下は８．８％程度であったと判断される。これは理論的に予測された４．８％よりやや大きいが、各セルの抵抗値にバラツキがあるための誤差であると推測される。 In evaluating the influence of the disconnection of the maximum power generation amount, this functional element is rich in flexibility and stretchability, so it is difficult to make the applied temperature difference and the distribution in the element strictly constant. There are challenges. As a result, variations in measurement values and fluctuations due to time occur, and the influence is reduced by taking the average of the relative values of the generated power at each temperature in Table 4. The average value of the amount of generated power at each temperature in Table 4 is 0.994, and it is determined that the decrease in maximum output is only about 0.6% due to disconnection at one location. This is slightly better than the theoretically predicted 2.5%, but it is judged to be a reasonable value considering the above error factors.
Further, from the measured change in element resistance, the element conductance is 0.912 times, and it is determined that the decrease due to disconnection at one place is about 8.8%. This is slightly larger than the theoretically predicted value of 4.8%, but is estimated to be an error due to variation in the resistance value of each cell.
　本実施例による機能性素子の網目状構造の切断耐性をより定量的に評価するため、等価な回路を用いたモンテカルロ回路シミュレーションを実施した。図１９は、シミュレーションに用いた機能性素子の等価回路モデルを示している。図１９の等価回路モデルは、ｐ型またはｎ型の熱電糸における結節点から結節点までの等価回路を、符号２１で示されるような電圧源で表したモデルである。図１９の等価回路モデルにおいて、電圧源は、それぞれ、ＶｐまたはＶｎの熱起電力を与えることができ、図示しないが電圧源の内部に直列に抵抗Ｒが接続されている。今回のモンテカルロ回路シミュレーションでは、この熱起電力をＶｐ＝Ｖｎ＝０．００１（Ｖ）として回路シミュレーションを実施した。モンテカルロ回路シミュレーションでは、電圧源（Ｖ１～Ｖ６０）の各々の抵抗Ｒの値を、与えられた切断確率で無限大と見做せるほど大きく設定し、それ以外は１００Ωとして、回路に生じる電圧と電流を計算した。
　なお、図１９において、電圧源（Ｖ６１，Ｖ６２）は、素子の電流－電圧特性を得るために入れた電圧源であり、これらは内部抵抗は０（ゼロ）としている。また、符号２２で示される三角マークは、基準電位（０Ｖ）を表している。
　図１９に示す等価回路モデルは、π型熱電変換セルの直列数３ユニット、並列数１０ユニットの接続に相当する回路であり、各編み目の発電機能は、内部抵抗を持った電圧源で表されている。電圧源の内部抵抗を乱数によって設定された確率で無限大とみなせるほどに大きくすることで、ある一定確率で編み目を構成する紡績糸が切断されることの影響を再現した。計算は、リニアテクノロジー社のＬＴｓｐｉｃｅを用いた。 In order to more quantitatively evaluate the cutting resistance of the network structure of the functional element according to this example, a Monte Carlo circuit simulation using an equivalent circuit was performed. FIG. 19 shows an equivalent circuit model of the functional element used in the simulation. The equivalent circuit model of FIG. 19 is a model in which an equivalent circuit from a node point to a node point in a p-type or n-type thermoelectric yarn is represented by a voltage source as indicated by reference numeral 21. In the equivalent circuit model of FIG. 19, each voltage source can provide a thermoelectromotive force of V p or V n , and a resistor R is connected in series inside the voltage source (not shown). In this Monte Carlo circuit simulation, the circuit simulation was carried out with this thermoelectromotive force as V p = V n = 0.001 (V). In the Monte Carlo circuit simulation, the value of the resistance R of each voltage source (V1 to V60) is set so large that it can be regarded as infinite with a given cutting probability, and the others are set to 100Ω, and the voltage and current generated in the circuit Was calculated.
In FIG. 19, voltage sources (V61, V62) are voltage sources used for obtaining the current-voltage characteristics of the element, and these have an internal resistance of 0 (zero). A triangular mark indicated by reference numeral 22 represents a reference potential (0 V).
The equivalent circuit model shown in FIG. 19 is a circuit equivalent to the connection of 3 units in series and 10 units in parallel of π-type thermoelectric conversion cells, and the power generation function of each stitch is represented by a voltage source having an internal resistance. ing. By increasing the internal resistance of the voltage source so that it can be regarded as infinite with a probability set by a random number, the effect of cutting the spun yarn constituting the stitches with a certain probability was reproduced. The calculation used LTspice from Linear Technology.
　編み目を構成するＣＮＴ紡績糸の切断確率を０から５０％まで変化させ、それぞれ１００回ずつ試行した結果の機能性素子の出力の変化を図２０に示す。図２０に示すグラフの縦軸は、切断がないときの出力で規格化した機能性素子の最大出力電力を表しており、エラーバーは１００回の試行結果の最大と最小を表し、グラフ中の“○”はその平均を表している。図２０に示すグラフでは、機能性素子に期待される出力は、切断確率の上昇に伴って、ほぼ直線的に減少してゆくが、５０％の切断確率となっても、まだ機能性素子の出力は残存する可能性が高いことが示されている。
　比較のために、同等の直列数と並列数であるが網目状の接続を有さない、従来型の単純な並列数１０ユニットの場合の素子の出力の計算結果を、切断確率２０％について点線で示してある。切断確率２０％において、従来型の単純な並列数１０ユニットの場合は、既に出力が全く失われる可能性があるのに対して、本実施例の機能性素子の場合は、最低でも３０％程度の出力が残存していることが示された。この結果は、本実施例の機能性素子の構造が、実使用環境下での機能性素子の主力安定性と寿命の延長に大きく貢献することを示すものである。 FIG. 20 shows the change in the output of the functional element as a result of changing the cutting probability of the CNT spun yarn constituting the stitch from 0 to 50% and trying 100 times each. The vertical axis of the graph shown in FIG. 20 represents the maximum output power of the functional element normalized by the output when there is no disconnection, the error bar represents the maximum and minimum of the 100 trial results, “O” represents the average. In the graph shown in FIG. 20, the output expected for the functional element decreases almost linearly as the cutting probability increases. However, even if the cutting probability is 50%, the output of the functional element still remains. It has been shown that the output is likely to remain.
For comparison, the calculation result of the element output in the case of the conventional simple parallel number of 10 units having the same series number and the parallel number but having no mesh-like connection is shown with a dotted line with a cutting probability of 20%. It is shown by. In the case of the cutting probability of 20%, in the case of the conventional simple parallel number of 10 units, the output may already be lost at all, whereas in the case of the functional element of this embodiment, at least about 30%. Output remained. This result shows that the structure of the functional element of this example greatly contributes to the main stability and the extension of the lifetime of the functional element in the actual use environment.
　本発明の機能性素子は、スマートハウスやスマートビルディングのためのセンサマトリックスを形成するための分散電源や、エナジーハーベスティング素子として、住宅、オフィス、自動車における排出熱エネルギーの再利用を図る熱電変換素子、ステッカー型の生体情報計測器（体温、脈拍、心電モニターなど）の電源などに利用できる。
　また、熱電変換素子は熱電対と同じ構造を有していることから、本発明の機能性素子は、汎用性の高い面状の高感度内外温度差センサ、自動車のシートやオフィスの椅子あるいはカーペットなどに組み込む人感センサなどにも利用できる。
　また、発電に用いるゼーベック効果と冷却に用いるペルチェ効果は本質的に可逆の現象であることから、本発明の機能性素子は、自動車、電車、航空機などの座面や背もたれに用いる布状ペルチェ冷却素子、加熱・冷却機能を備えた衣服などにも利用できる。 The functional element of the present invention is a distributed power source for forming a sensor matrix for a smart house or smart building, or a thermoelectric conversion element for reusing exhaust heat energy in a house, office, or automobile as an energy harvesting element It can be used as a power source for sticker-type biological information measuring instruments (body temperature, pulse, electrocardiogram monitor, etc.).
In addition, since the thermoelectric conversion element has the same structure as the thermocouple, the functional element of the present invention is a highly versatile planar high-sensitivity internal / external temperature difference sensor, automobile seat, office chair or carpet. It can also be used as a human sensor incorporated in the
In addition, since the Seebeck effect used for power generation and the Peltier effect used for cooling are essentially reversible phenomena, the functional element of the present invention is a cloth-like Peltier cooling used for seats and backrests of automobiles, trains, airplanes, etc. It can also be used for devices and clothing with heating and cooling functions.
　１，１ａ～１ｄ　ｐ型ＣＮＴ紡績糸
　２，２ａ～２ｃ　ｎ型ＣＮＴ紡績糸
　３　絶縁性基材
　４　銅線
　５　銀ペースト
　６ａ，６ｂ　断線箇所
　７ａ，７ｂ　不良化範囲
　８　断線箇所
　１０　ＣＮＴ
　１１　ＣＮＴ分散剤
　１２　ディスペンサー
　１３　回転台
　１４　容器
　１５　凝集液
　１６　紡糸状ＣＮＴ
　２１　電圧源
　２２　基準電位
　Ｖ１～Ｖ６２　電圧源 1, 1a to 1d p-type CNT spun yarn 2, 2a to 2c n-type CNT spun yarn 3 Insulating base material 4 Copper wire 5 Silver paste 6a, 6b Broken point 7a, 7b Defect range 8 Broken point 10 CNT
11 CNT dispersant 12 Dispenser 13 Turntable 14 Container 15 Aggregate 16 Spinned CNT
21 Voltage source 22 Reference potential V1 to V62 Voltage source

Claims (14)

  1. 　絶縁性基材の厚み方向の温度差を利用するπ型熱電変換セルの直列構造が複数並列に並び、ｐ型とｎ型が切り換わる部位で、発電時に同電位となる段間が電気的に接続されるトポロジーを有する素子であって、
    　前記絶縁性基材は、断熱性と柔軟性を有するシート状または帯状で、使用環境において基材単体で形状保持し得る基材強度を有し、
    　前記素子は、断熱性を有する導電性繊維状物質から成るｎ型紡績糸とｐ型紡績糸が、前記絶縁性基材に交互かつ並行して縫い込まれ、それぞれ前記絶縁性基材の表面と裏面を交互に貫通する際に互いに電気的に接続されており、
    　前記絶縁性基材と前記紡績糸が互いに緩やかに結合し、π型熱電変換セルが電気回路として直列接続と並列接続の両方で網目状に縦横に接続され、断線に対する素子の耐性を高めたことを特徴とする機能性素子。     A plurality of series structures of π-type thermoelectric conversion cells that utilize the temperature difference in the thickness direction of the insulating base material are arranged in parallel, and the portion where the p-type and n-type are switched is electrically connected between the stages having the same potential during power generation. An element having a topology to be connected,
    The insulating base is a sheet or strip having heat insulation and flexibility, and has a base strength that can hold the shape of the base alone in the environment of use,
    In the element, n-type spun yarn and p-type spun yarn made of a conductive fibrous material having heat insulation properties are alternately and parallel sewn into the insulating base material, They are electrically connected to each other when penetrating backsides alternately,
    The insulating base material and the spun yarn are loosely bonded to each other, and the π-type thermoelectric conversion cell is connected as a network in both a series connection and a parallel connection in the form of a mesh, increasing the resistance of the element to disconnection. A functional element characterized by
  2. 　前記導電性繊維状物質の長手方向の熱伝導率が、１０Ｗ／ｍＫ未満に抑制されていることを特徴とする請求項１に記載の機能性素子。 2. The functional element according to claim 1, wherein a thermal conductivity in a longitudinal direction of the conductive fibrous substance is suppressed to less than 10 W / mK.
  3. 　前記ｎ型紡績糸と前記ｐ型紡績糸が、それぞれ前記絶縁性基材の表面と裏面を交互に貫通する際に糸を少なくとも１回交差させられ、交差部で電気的に接触していることを特徴とする請求項１又は２に記載の機能性素子。 The n-type spun yarn and the p-type spun yarn are crossed at least once when passing through the front surface and the back surface of the insulating base material alternately, and are in electrical contact at the crossing portion. The functional element according to claim 1, wherein:
  4. 　前記ｎ型紡績糸と前記ｐ型紡績糸が、それぞれ前記絶縁性基材の表面と裏面を交互に貫通する際に糸を交差あるいは接触させられ、交点あるいは接点に導電性ペーストによる電気的接続の補強が設けられたことを特徴とする請求項１～３の何れかに記載の機能性素子。 When the n-type spun yarn and the p-type spun yarn alternately pass through the front surface and the back surface of the insulating base material, the yarn crosses or is brought into contact with each other. The functional element according to any one of claims 1 to 3, wherein a reinforcement is provided.
  5. 　前記ｎ型紡績糸と前記ｐ型紡績糸が、それぞれ前記絶縁性基材の表面と裏面を交互に貫通する際に糸を交差あるいは接触させられ、交点あるいは接点が接着されたことを特徴とする請求項１～４の何れかに記載の機能性素子。 The n-type spun yarn and the p-type spun yarn are crossed or brought into contact with each other when the front and back surfaces of the insulating base material are alternately passed through, and the intersection or contact point is adhered. The functional element according to any one of claims 1 to 4.
  6. 　前記ｎ型紡績糸と前記ｐ型紡績糸が、前記絶縁性基材の厚み方向に対して斜めに貫通し、前記絶縁性基材の表面と裏面にそれぞれ露出される部分を増減させたことを特徴とする請求項１～５の何れかに記載の機能性素子。 The n-type spun yarn and the p-type spun yarn penetrated obliquely with respect to the thickness direction of the insulating base material, and the portions exposed on the front and back surfaces of the insulating base material were increased or decreased, respectively. The functional element according to any one of claims 1 to 5, wherein
  7. 　前記ｎ型紡績糸と前記ｐ型紡績糸が帯状、又は、前記ｎ型紡績糸と前記ｐ型紡績糸の断面が多角形もしくは楕円形であることを特徴とする請求項１～６の何れかに記載の機能性素子。 The n-type spun yarn and the p-type spun yarn are band-shaped, or the cross-section of the n-type spun yarn and the p-type spun yarn is a polygon or an ellipse. The functional element described in 1.
  8. 　前記絶縁性基材は、柔軟性および伸縮性あるいはその一方を有することを特徴とする請求項１～７の何れかに記載の機能性素子。 The functional element according to any one of claims 1 to 7, wherein the insulating substrate has flexibility and / or elasticity.
  9. 　前記絶縁性基材は、布又は紙、あるいは、発泡ポリマー、エラストマー、綿状凝集体及びゲル状凝集体から選択される素材を板状あるいはシート状に加工したものの何れかであることを特徴とする請求項８に記載の機能性素子。 The insulating base material is either cloth or paper, or a material selected from foamed polymers, elastomers, cotton-like aggregates, and gel-like aggregates, processed into a plate shape or a sheet shape. The functional element according to claim 8.
  10. 　前記絶縁性基材は、縫製されたものであり、縫製される際に、前記ｎ型紡績糸と前記ｐ型紡績糸が、同時に縫製されたことを特徴とする請求項１～９の何れかに記載の機能性素子。 10. The insulating base material according to claim 1, wherein the insulating base material is sewn, and the n-type spun yarn and the p-type spun yarn are sewn simultaneously at the time of sewing. The functional element described in 1.
  11. 　前記絶縁性基材は、π型熱電変換セルの厚みと実質的同一の径を有する縦糸と横糸を用いて縫製されたことを特徴とする請求項１０に記載の機能性素子。 The functional element according to claim 10, wherein the insulating base material is sewn using warp and weft having substantially the same diameter as the thickness of the π-type thermoelectric conversion cell.
  12. 　前記紡績糸は、カーボンナノチューブ（ＣＮＴ）、カーボンナノファイバー（ＣＮＦ）、グラフェン、グラフェンナノリボン、フラーレンナノウィスカー及び無機半導体ウィスカーの群から選択される１種以上の導電性ナノファイバーと、
    　ポリマー、デンドリマー、ポリペプチド及びタンパク質の群から選択される１種以上を主成分とする絶縁性材料又は導電性材料との複合材料から成ることを特徴とする請求項１～１１の何れかに記載の機能性素子。     The spun yarn includes at least one conductive nanofiber selected from the group consisting of carbon nanotubes (CNT), carbon nanofibers (CNF), graphene, graphene nanoribbons, fullerene nanowhiskers, and inorganic semiconductor whiskers;
    12. The insulating material comprising at least one selected from the group of polymers, dendrimers, polypeptides, and proteins, or a composite material with a conductive material. Functional elements.
  13. 　前記紡績糸は、０．１～１００μｍの径のＣＮＴから成る繊維を複数撚り合せた撚糸であることを特徴とする請求項１２に記載の機能性素子。 The functional element according to claim 12, wherein the spun yarn is a twisted yarn obtained by twisting a plurality of fibers made of CNTs having a diameter of 0.1 to 100 µm.
  14. 　請求項１～１３の機能性素子の製造方法であって、
    　前記ｎ型紡績糸と前記ｐ型紡績糸の一方を第１紡績糸、他方を第２紡績糸とし、前記絶縁基材の表面と裏面の一方を第１面、他方を第２面として、
    　第１紡績糸が前記絶縁性基材に直線状に波縫いされている状態で、
    　波縫いされた第１紡績糸に並行に隣接して第２紡績糸を波縫いする際に、第１面で一工程前に縫った第１紡績糸の第１面に露出している部分を交差させ、少なくとも１回捻じった後に縫うステップ、
    　次に、波縫いされた第２紡績糸に並行に隣接して第１紡績糸を波縫いする際に、第２面で一工程前に縫った第２紡績糸の第２面に露出している部分を交差させ、少なくとも１回捻じった後に縫うステップ、
    　上記のステップを繰り返すことにより、波縫いの方向と直交する方向に電流経路が形成され、該電流経路に沿ってπ型構造直列接合が形成されることを特徴とする機能性素子の作製方法。
          A method for producing a functional element according to claims 1 to 13,
    One of the n-type spun yarn and the p-type spun yarn is a first spun yarn, the other is a second spun yarn, one of the front and back surfaces of the insulating substrate is a first surface, and the other is a second surface,
    In a state where the first spun yarn is wave-stitched linearly on the insulating base material,
    When the second spun yarn is wave-sewn adjacently in parallel to the first spun yarn that has been wave-stitched, the portion exposed on the first surface of the first spun yarn that has been sewn one step before on the first surface Crossing and sewing after twisting at least once,
    Next, when the first spun yarn is wave-sewn adjacently in parallel with the second spun yarn that has been wave-stitched, the second surface is exposed to the second surface of the second spun yarn that has been sewn one step before. Crossing the parts that have been crossed and twisting at least once,
    By repeating the above steps, a current path is formed in a direction orthogonal to the direction of wave stitching, and a π-type structure series junction is formed along the current path.
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