CN109855526B - Resistance-type flexible strain sensor based on drying-mediated self-assembly and preparation method thereof - Google Patents
Resistance-type flexible strain sensor based on drying-mediated self-assembly and preparation method thereof Download PDFInfo
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Abstract
The invention relates to a resistance-type flexible strain sensor for forming parallel cracks based on colloidal particle drying-mediated self-assembly and a preparation method thereof, wherein the flexible strain sensor comprises the following components which are sequentially arranged from bottom to top: the sensor comprises a flexible substrate, a sensitive layer and a conductive layer; the flexible substrate is a thin film of flexible material; the sensitive layer is prepared from a film generated by drying colloidal dispersion; the upper surface of the base plate is provided with a regular crack array structure; the conducting layer is provided with a pair of copper sheet electrodes, and the two electrodes are respectively positioned at two ends of the conducting layer; an enameled wire is led out from each electrode. The flexible strain sensor provided by the invention can be attached to the surface of human skin or attached to clothes, so that wearable monitoring of human respiration, pulse, gait, joint movement and the like can be realized. The flexible strain sensor adopts a dry dielectric method, realizes the self-assembly of colloid particles to form parallel cracks, has the characteristics of high sensitivity, quick and efficient preparation process, simple and environment-friendly preparation process, contribution to large-area manufacturing, low cost and the like, and has wide application prospect.
Description
Technical Field
The invention relates to a resistance-type flexible strain sensor based on dry-mediated self-assembly and a preparation method thereof, belonging to the flexible sensor technology.
Background
Sensors are a generic term for a type of function-detecting device that can convert external information into a visible, readable, storable electrical signal or other desired form of information for output. Strain sensors are a type of sensor that generates strain based on the force applied to an object and converts it into other readable signals. In recent years, the conventional strain sensor is greatly limited in flexibility and detection accuracy due to the properties of the material, and is not suitable for many emerging fields requiring flexibility. Therefore, flexible strain sensors are produced.
A flexible strain sensor is a flexible electronic device for converting mechanical deformation of a sensitive body into an electrical signal, can be attached to an area with a curved surface and a complex structure, realizes deformation such as corresponding stretching, bending and twisting along with the flexible strain sensor, conveniently and accurately and rapidly measures special environments and signals, has wide application requirements in the fields of human body sign detection (monitoring), limb joint movement, intelligent electronics, intelligent skin covering and the like, and arouses more and more extensive attention of people. In recent years, researchers in the related field have prepared various flexible strain sensors aiming at the requirement, and mainly a flexible substrate is coated with a strain sensitive material, and the strain behavior is monitored through the resistance change in the working process. In the current research, on one hand, researchers strive to select sensitive materials with excellent electrical and mechanical properties to improve the sensitivity and stability of strain sensors, such as carbon nanotubes, graphene, PEDOT: PSS, and the like; on the other hand, researchers realize the optimization of the performance of the sensor by introducing a fine micro-nano structure, and the currently reported micro-nano structure comprises layering, folding, fabric, cracks and the like. However, the materials such as graphene and carbon nanotubes are complex to prepare and high in cost, and the development of flexible strain sensors is limited. Compared with other micro-nano structures, the crack structure is easy to be favored by researchers due to simple structure and signal acquisition.
The working principle of the flexible strain sensor with the crack structure is as follows: processing a crack with a specific size on the surface of the flexible substrate, and slightly deforming the flexible substrate under the action of an external load to change the distance between two walls of the crack, so as to induce the resistance to change and finish measurement. Based on the sequential preparation of a plurality of flexible strain sensors with crack structures, a plurality of scientific groups effectively improve the sensitivity of the flexible strain sensors. The sensors with crack structures that have been reported so far are mainly classified into: the cracks with irregular size distribution are generated by mechanical means such as bending, tearing, stretching and the like. However, the geometrical parameters of the cracks are one of the decisive factors influencing the performance of the flexible strain sensor, and the stability and the service life of the sensor are greatly reduced due to different sizes and disordered distribution of crack structures in the working process; processing a template with a regular crack structure by methods such as photoetching, oxidation, nanoimprint and the like, and transferring the crack array to the surface of the flexible substrate by a template method. By adopting new processing technologies such as photoetching, nanoimprint lithography and the like, the spontaneous disordered crack structure is converted into an accurate and controllable crack structure, and although the optimization of the performance of the sensor is realized, the processing difficulty of a mould with a fine crack structure is high, the processing period is long, the processing cost is high, and the commercialization process of the flexible strain sensor with the strain of the crack structure is severely restricted. Therefore, the realization of the efficient and low-cost preparation technology of the flexible strain sensor based on the crack structure is the key for realizing the popularization and the application of the flexible strain sensor.
Disclosure of Invention
Technical problem to be solved
In order to overcome the technical defects of long preparation period, difficult processing, high technical requirements and the like of the flexible strain sensor based on the crack structure in the prior art, the invention provides the resistance-type flexible strain sensor based on the dry-mediated self-assembly and the preparation method thereof, the processing technology is simple, the preparation is rapid, and the crack arrays which are arranged in parallel and have uniform geometric parameters can be processed on the flexible substrate.
(II) technical scheme
In order to achieve the purpose, the invention adopts the main technical scheme that:
a dry-mediated self-assembly based resistive flexible strain sensor includes,
arranged from bottom to top in sequence: the sensor comprises a flexible substrate, a sensitive layer and a conductive layer;
the flexible substrate is a thin film of flexible material;
the sensitive layer is prepared from a film generated by drying colloidal dispersion; the upper surface of the base plate is provided with a crack array structure which is relatively consistent in size and uniform in distribution; the conducting layer is provided with a pair of copper sheet electrodes, and the two electrodes are respectively positioned at two ends of the conducting layer;
an enameled wire is led out from each electrode.
The resistive flexible strain sensor as described above, preferably, the crack array structure is a parallel crack formed by directed drying-mediated self-assembly of a colloidal dispersion.
Furthermore, in a free state of the crack array structure, the width of the cracks is within the range of 1-6 mu m, the interval of the cracks is within the range of 10-40 mu m, and the depth of the cracks is within the range of 1-4 mu m.
In the above-mentioned resistive flexible strain sensor, preferably, the colloidal dispersion of the sensitive layer is any one of polystyrene latex particles, aqueous acrylic resin, titanium dioxide nanoparticles and silica nanoparticles.
In order to generate parallel cracks by self-assembly of the dried colloid particles, the water-based acrylic resin with the particle size of 40-80nm is preferred.
As mentioned above, preferably, the flexible material is one of polyamide, Polydimethylsiloxane (PDMS), polyimide or polyethylene terephthalate (PET).
In order to avoid allergic reactions between the flexible substrate and the human skin, the flexible material is preferably a polyethylene terephthalate (PET) film with a thickness of 100 μm.
In the above resistance-type flexible strain sensor, preferably, the conductive layer is made of gold, silver, copper, or chromium metal nanoparticles, the thickness of the conductive layer is 40-50 nm, and the geometric parameters of the surface crack are substantially the same as those of the sensitive layer structure in a natural state.
Furthermore, the thickness of the sensitive layer after drying is about 9-18 μm.
In another aspect, the present invention also provides a method for preparing a dry-mediated self-assembly-based resistive flexible strain sensor as described above, including the following steps:
s1, preparing colloidal dispersion aqueous dispersion liquid;
s2, preprocessing the flexible substrate;
s3, preparing a sensitive layer with a regular crack array on the surface on the upper surface of the flexible substrate by utilizing a colloidal dispersion aqueous dispersion drying-mediated self-assembly method;
s4, preparing a conducting layer on the surface of the sensitive layer crack structure through sputtering and coating;
and S5, attaching copper sheet electrodes to two ends of the conductive layer, and leading out an enameled lead on each copper sheet electrode to obtain the flexible strain sensor.
In the preparation method described above, preferably, the step S1 includes the following operations: adding colloidal dispersion solute with the particle size of 40-80nm into deionized water to obtain colloidal dispersion aqueous dispersion liquid with a certain concentration; and (3) ultrasonically oscillating the prepared colloidal dispersion aqueous dispersion, filtering, sealing and standing the filtrate obtained by filtering overnight to obtain the colloidal dispersion aqueous dispersion. The concentration of the colloidal dispersion solute in the ionized water is 0.1-0.3 g/mL.
Preferably, the material of the colloidal dispersion solute is any one of polystyrene latex particles, aqueous acrylic resin, titanium dioxide nanoparticles and silicon dioxide nanoparticles.
In the preparation method described above, preferably, the pretreatment in step S2 is:
and (3) ultrasonically cleaning the flexible substrate by using water, acetone and isopropanol in sequence, and then drying by using nitrogen to obtain the ultra-clean flexible substrate.
Further, the ultrasonic cleaning time of water, acetone and isopropanol is 10-30 minutes respectively.
In the preparation method described above, preferably, the step S3 includes the following operations: ultrasonically oscillating the colloidal dispersion aqueous dispersion prepared in the step S1, and uniformly dripping the colloidal dispersion aqueous dispersion to the upper end of a flexible substrate; the flexible substrate is obliquely arranged at a certain angle, and the colloidal dispersion aqueous solution freely flows to cover the surface of the flexible substrate under the action of gravity; drying is carried out, and the water in the aqueous dispersion of the colloidal dispersion is evaporated and cracks are gradually generated in parallel to each other on the surface in contact with the air.
Further, preferably, during drying, the flexible substrate can be placed in a constant temperature environment with the temperature of 60-100 ℃; the inclination angle is preferably 15-45 degrees.
In order to accelerate the generation of the crack structure, the flexible substrate is heated by a constant-temperature heating table. Within 5 minutes, the sensitive layer acrylic resin colloidal particles are dried and self-assembled to form parallel cracks with uniform size and orderly distribution.
In the above manufacturing method, preferably, in step S3, the ultrasonic oscillation time is 10 to 30 minutes, the thickness of the flexible substrate is 100 μm, the thickness of the sensitive layer is about 15 μm, and in step S4, the thickness of the conductive layer is 40 to 50 nm.
The prepared flexible strain sensor can be attached to the surface of human skin or attached to clothes, and is used for realizing wearable monitoring of human respiration, pulse, gait, joint movement and the like. The flexible strain sensor adopts a dry dielectric method, realizes the self-assembly of colloid particles to form parallel cracks, has the characteristics of high sensitivity, quick and efficient preparation process, simple and environment-friendly preparation process, contribution to large-area manufacturing, low cost and the like, and has wide application prospect.
(III) advantageous effects
The invention has the beneficial effects that:
(1) compared with other resistance type strain sensors based on crack structures, the flexible strain sensor prepared by drying and self-assembling colloidal particles has the advantages that the geometrical parameters of cracks are highly controllable, and meanwhile, the damage caused by external force is avoided, so that the high sensitivity and the stability of the sensor are ensured.
(2) The crack structure realizes the self-assembly of colloid particles by utilizing the synergistic action of gravity and drying, and can process the crack with a specific size according to the actual condition; in addition, the crack structure is generated quickly, and the preparation period of the sensor is greatly shortened.
(3) The flexible strain sensor is simple in preparation device, and complex processes such as photoetching are not needed; in addition, the manufacturing cost is low, and the application prospect is wide.
Drawings
FIG. 1 is a top view of a resistive flexible strain sensor;
FIG. 2 is a longitudinal cross-sectional view of a resistive flexible strain sensor;
FIG. 3 is a crack array structure;
fig. 4 is a schematic view of a manufacturing apparatus for a resistive flexible strain sensor according to an embodiment.
[ description of reference ]
1: a conductive layer;
2: a sensitive layer;
3: a flexible substrate;
4: a first electrode;
5: a second electrode;
6: enamelling the wires;
7: a wood board;
8: a glass slide;
9: a dropper;
10: a constant temperature heating table.
Detailed Description
For the purpose of better explaining the present invention and to facilitate understanding, the present invention will be described in detail by way of specific embodiments with reference to the accompanying drawings.
Example 1
A flexible strain sensor based on dry-mediated self-assembly, as shown in fig. 1 and 2, comprising, arranged from top to bottom: a conductive layer 1, a sensitive layer 2 and a flexible substrate 3.
The conductive layer 1 is sputter coated on the upper surface of the sensitive layer 2. The structural parameters of the cracks on the surface of the conductive layer are basically the same as those of the sensitive layer in a natural state.
The conducting layer 1 is provided with two electrodes (a first electrode 4 and a second electrode 5), and an enameled wire 6 is respectively led out from the two electrodes for collecting electric signals.
The two electrodes are not in contact with each other. Preferably, the first electrode 4 is located at one end of the strain sensor and the second electrode 5 is located at the other end of the strain sensor, so as to maximize the area of the crack working region between the two electrodes.
The upper surface of the sensitive layer is provided with a highly regular crack array structure. The crack structure is a parallel crack with highly controllable geometric parameters formed by the self-assembly of the colloidal dispersion mediated by directional drying.
Specifically, the crack array structure pattern is shown in fig. 3. In this embodiment, regular cracks with consistent relative widths and high parallelism in the crack array structure pattern are selected.
Preferably, the width of the cracks is in the range of 1-6 μm, the distance between the cracks is in the range of 10-40 μm, and the depth of the cracks is between 1-4 μm in the natural state of the parallel crack array structure. The flexible substrate 3 in the flexible strain sensor of the present invention is made of a flexible material. The flexible material is one of Polyamide (PA), Polydimethylsiloxane (PDMS), Polyimide (PI) or polyethylene terephthalate (PET).
In order to prevent the flexible pressure sensor from generating allergy and inflammation after contacting with the skin, the flexible substrate of the embodiment of the invention adopts a polyethylene terephthalate (PET) film with the thickness of about 100 μm. Too thick a thickness affects the reaction time and sensitivity, and too thin a thickness affects the stability, so that a thickness of 100 μm is used.
In order to ensure that the crack structure of the flexible strain sensor has higher sensitivity, the thickness of the colloid film of the sensitive layer is not too low; in order to ensure that the flexible strain sensor has excellent flexibility and stability, the thickness of the colloid film of the sensitive layer is not too high; preferably 15 μm.
Preferably, the material of the conducting layer is silver (Ag) nano particles; the thickness was 50 nm.
Example 2
The embodiment provides a preparation method of a resistance-type flexible strain sensor based on dry-mediated self-assembly, which specifically comprises the following steps:
s1, preparing the acrylic resin colloid aqueous dispersion.
In this example, a parallel crack array was prepared using a neat scalable technique using a film thickness gradient formed by colloidal dispersions under the action of gravity flow.
Specifically, step S1 includes:
s101, adding water-based acrylic resin with the particle size of 40-80nm into deionized water to obtain acrylic resin water-based dispersion with the concentration of 0.3 g/mL.
S102, ultrasonically oscillating the prepared acrylic resin aqueous dispersion for 30min, and then filtering to obtain filtrate.
And S103, sealing and storing the filtrate obtained by filtering in a sealed bottle, and standing overnight to obtain the acrylic resin colloidal dispersion.
S2, preprocessing the flexible substrate.
In this embodiment, in order to avoid that impurities on the surface of the substrate affect the surface quality of the sensitive layer crack structure, a cleaning pretreatment operation needs to be performed on the flexible substrate before preparation, which is specifically as follows:
s201, pre-cutting the flexible substrate polyethylene terephthalate (PET) into 8 × 3cm2The rectangular block of (2).
S202, sequentially performing ultrasonic treatment on the cut flexible substrate for 20 minutes in 300W ultrasonic equipment by using deionized water, acetone and isopropanol to obtain the ultra-clean flexible substrate.
S3, preparing a sensitive layer with a regular crack array on the surface on the upper surface of the flexible substrate by utilizing a colloid dispersion aqueous solution drying-mediated self-assembly method, as shown in figure 4.
S301, extracting 1ml of acrylic resin colloid prepared in step S1 in advance and carrying out ultrasonic oscillation for 30 minutes.
And S302, placing a rectangular wood board 7 at an angle of 30 degrees, adhering the flexible substrate treated in the step S2 to the surface of the wood board 7 by using an adhesive tape, and fixing a clean laboratory glass slide 8 at the lower end of the flexible substrate 3 to prevent the colloid from overflowing the flexible boundary under the action of gravity.
And S303, vertically placing a clean laboratory glass slide 8 on the upper end of the flexible substrate 3, and uniformly dripping acrylic resin colloid on the upper end of the flexible substrate along the surface of the glass slide 8 by using a rubber head dropper 9 or an injector. Under the action of gravity, the colloid on the upper end of the flexible substrate 3 flows until the whole surface of the flexible substrate 3 is uniformly covered.
S304, a constant temperature heating table 10 is placed below the wood board, and the temperature is set to be 60 ℃ to heat the flexible substrate, so that the drying speed of the colloid is accelerated.
Within 5 minutes, a sensitive layer film is formed after the colloid is dried, and the surface of the film has a crack array structure with regular size and ordered arrangement along the drying direction (the long side of the flexible substrate). The array was linear overall, but a small number of cracks perpendicular to each other appeared in the region where drying began. In the embodiment, the thickness of the sensitive layer is approximately equal to 15 μm, the width of the crack array structure is in the range of 1-6 μm in a natural state, the crack spacing is in the range of 10-40 μm, and the crack depth is in the range of 1-4 μm. The principle of parallel cracks generated on the upper surface of the sensitive layer is as follows: the colloidal particles with liquid phase solvent self-assemble into various ordered structures after drying. Highly ordered crack structures can be formed over a large area by appropriate boundary and thickness gradient control. The formation of crack structures is a direct result of the competition between crack opening induced stress relaxation and crack opening induced stress relaxation due to solvent loss induced stress increase. First, evaporation of the water in the colloidal aqueous dispersion concentrates the colloidal solute nanoparticles into a dense film, which is free of cracks during drying. Further evaporation of water causes the gel to contract inward with the air contact line, creating a negative capillary pressure, the magnitude of which is proportional to the surface tension of the water and inversely proportional to the radius of curvature of the interparticle meniscus. This pressure further compacts the colloidal particles in a direction perpendicular to the substrate, thereby stretching the colloidal film in a parallel direction. When the tensile stress exceeds the yield stress of the filled nanoparticle film, the strain energy stored in the film can be released by creating a new interface, thereby forming cracks. As the drying front moves inward due to continued evaporation, the newly formed crack may act as a nucleation site and propagate in the direction of the drying front. Finally, under the combined action of gravity and drying, parallel cracks are generated on the surface of the flexible substrate, and no obvious defects exist.
Wherein the width of the crack and the crack spacing are related to the inclination angle of the wood board, and the crack depth is related to the width. The thickness gradient can be formed in the vertical direction by reasonably controlling the inclination angle of the wood board, and then cracks with different widths are generated to meet different working condition requirements.
S4, sputtering and coating a silver nanoparticle conducting layer with the thickness of 50nm on the surface of the sensitive layer crack structure. The size parameter of the surface crack of the conductive layer is basically the same as that of the sensitive layer in a natural state.
And S5, selecting an area with better parallelism in the crack array structure on the surface of the sensitive layer, and cutting the area with the size (l multiplied by w) of 30mm multiplied by 10 mm.
And S6, attaching copper sheet electrodes to two ends of the conductive layer, and respectively leading out an enameled wire to obtain the flexible strain sensor. Wherein, the two electrodes are not intersected with each other and simultaneously ensure that the electrodes are respectively arranged at the two ends of the sensitive layer as much as possible to obtain the maximum effective working area.
Example 3
The embodiment also provides another preparation method of the resistance-type flexible strain sensor based on dry-mediated self-assembly, and specifically, the method comprises the following steps:
s1, preparing polystyrene colloid.
In this example, a parallel crack array was prepared using a neat scalable technique using a film thickness gradient formed by colloidal dispersions under the action of gravity flow.
Specifically, step S1 includes:
s101, adding polystyrene latex particles with the particle size of 50nm into deionized water to obtain the polystyrene colloidal particle aqueous dispersion with the concentration of 0.1 g/mL.
S102, ultrasonically oscillating the prepared polystyrene colloidal particle aqueous dispersion for 30min, and then filtering to obtain a filtrate.
And S103, sealing and storing the filtrate obtained by filtering in a sealed bottle, and standing overnight to obtain the polystyrene colloid.
S2, preprocessing the flexible substrate.
In this embodiment, in order to avoid that impurities on the surface of the substrate affect the surface quality of the sensitive layer crack structure, a cleaning pretreatment operation needs to be performed on the flexible substrate before preparation, which is specifically as follows:
s201, pre-cutting the flexible substrate polyethylene terephthalate (PET) into 8 × 3cm2The rectangular block of (2).
S202, sequentially performing ultrasonic treatment on the cut flexible substrate for 20 minutes in 300W ultrasonic equipment by using deionized water, acetone and isopropanol to obtain the ultra-clean flexible substrate.
S3, preparing a sensitive layer with a regular crack array on the surface on the upper surface of the flexible substrate by utilizing a colloid dispersion aqueous solution drying-mediated self-assembly method.
S301, extracting 1ml of polystyrene colloid prepared in step S1 in advance and carrying out ultrasonic oscillation for 20 minutes.
And S302, placing a rectangular wood board 7 at an angle of 35 degrees, adhering the flexible substrate treated in the step S2 to the surface of the wood board 7 by using an adhesive tape, and fixing a clean laboratory glass slide 8 at the lower end of the flexible substrate 3 to prevent the colloid from overflowing the flexible boundary under the action of gravity.
And S303, vertically placing a clean laboratory glass slide 8 on the upper end of the flexible substrate 3, and uniformly dripping polystyrene colloid on the upper end of the flexible substrate along the surface of the glass slide 8 by using a rubber head dropper 9 or a syringe. Under the action of gravity, the colloid on the upper end of the flexible substrate 3 flows until the whole surface of the flexible substrate 3 is uniformly covered.
S304, a constant temperature heating table 10 is placed below the wood board, and the temperature is set to be 70 ℃ to heat the flexible substrate, so that the drying speed of the colloid is accelerated.
Within 5 minutes, a sensitive layer film is formed after the colloid is dried, and the surface of the film has a crack array structure with regular size and ordered arrangement along the drying direction (the long side of the flexible substrate).
S4, preparing a silver conducting layer of 40nm on the surface of the sensitive layer crack structure through sputtering and coating;
and S5, attaching copper sheet electrodes to two ends of the conductive layer, and leading out an enameled lead on each copper sheet electrode to obtain the flexible strain sensor.
Compared with the technologies such as photoetching, femtosecond laser, nano imprinting and the like, the preparation method of the flexible resistance type strain sensor provided by the invention is simple to operate, the required equipment is common instruments in a laboratory, the preparation of the sensitive layer is within 5 minutes, the cost is low, and the large-area manufacturing is easy to realize. Taking photolithography as an example, a general photolithography process includes the steps of cleaning and drying the surface of a substrate, priming, spin-coating a photoresist, soft-baking, alignment exposure, post-baking, developing, hard-baking, etching, detecting and the like, and the preparation process is complex in operation and long in preparation period. In addition, the low-end photoetching machine for production line and research is a proximity and contact photoetching machine, the resolution is usually more than several micrometers, the high-precision photoetching machine has extremely high cost, and the large-area manufacturing of the strain sensor is difficult to realize. It is to be understood that the invention is not limited to the specific arrangements and instrumentality described above and shown in the drawings. A detailed description of known methods is omitted herein for the sake of brevity.
In the above embodiments, several specific steps are described and shown as examples. However, the method processes of the present invention are not limited to the specific steps described and illustrated, and those skilled in the art can make various changes, modifications and additions or change the order between the steps after comprehending the spirit of the present invention.
Claims (4)
1. A dry-mediated self-assembly based resistive flexible strain sensor, comprising:
arranged from bottom to top in sequence: the sensor comprises a flexible substrate, a sensitive layer and a conductive layer;
the flexible substrate is a thin film of flexible material;
the sensitive layer is prepared from a film generated by drying colloidal dispersion; the upper surface of the base plate is provided with a crack array structure which is relatively consistent in size and uniform in distribution;
the conducting layer is provided with a pair of copper sheet electrodes, and the two electrodes are respectively positioned at two ends of the conducting layer;
an enameled wire is led out of each electrode;
the crack array structure is a parallel crack formed by self-assembly mediated by directional drying of colloidal dispersion; in a free state, the width of the cracks is within the range of 1-6 mu m, the spacing of the cracks is within the range of 10-40 mu m, and the depth of the cracks is within the range of 1-4 mu m;
the colloidal dispersion of the sensitive layer is any one of polystyrene latex particles, water-based acrylic resin, titanium dioxide nanoparticles and silicon dioxide nanoparticles;
the flexible material is one of polyamide, polydimethylsiloxane, polyimide or polyethylene terephthalate;
the conducting layer is made of gold, silver, copper or chromium metal nano particles, the thickness of the conducting layer is 40-50 nm, and the geometric parameters of surface cracks of the conducting layer are basically the same as those of the sensitive layer structure in a natural state; the thickness of the sensitive layer after drying is 9-18 mu m.
2. A preparation method of a resistance-type flexible strain sensor is characterized by comprising the following steps:
s1, preparing colloidal dispersion aqueous dispersion liquid;
s2, preprocessing the flexible substrate;
s3, preparing a sensitive layer with a regular crack array on the surface on the upper surface of the flexible substrate by utilizing a colloid dispersion aqueous dispersion drying-mediated self-assembly method;
s4, preparing a conducting layer on the surface of the sensitive layer crack structure through sputtering and coating;
s5, attaching copper sheet electrodes to two ends of the conductive layer, and leading out an enameled lead on each copper sheet electrode to obtain a flexible strain sensor;
wherein the step S1 includes the following operations: adding colloidal dispersion solute with the particle size of 40-80nm into deionized water to obtain colloidal dispersion aqueous dispersion with a certain concentration, carrying out ultrasonic oscillation, filtering, sealing and standing filtrate overnight to obtain the required colloidal dispersion aqueous dispersion; the concentration of the colloidal dispersion solute in the ionized water is 0.1-0.3 g/mL; the colloidal dispersion solute is made of any one of polystyrene latex particles, water-based acrylic resin, titanium dioxide nanoparticles and silicon dioxide nanoparticles;
the step S3 includes the following operations: ultrasonically oscillating the colloidal dispersion aqueous dispersion prepared in the step S1, and uniformly dripping the colloidal dispersion aqueous dispersion to the upper end of a flexible substrate; the flexible substrate is obliquely arranged at a certain angle, and the colloidal dispersion aqueous solution freely flows to cover the surface of the flexible substrate under the action of gravity; drying is carried out, the water in the aqueous colloidal dispersion evaporates and cracks are gradually generated parallel to each other on the surface in contact with the air.
3. The method of claim 2, wherein the step S2 is performed by sequentially ultrasonically cleaning the flexible substrate with water, acetone, and isopropanol, and then drying with nitrogen.
4. The method of claim 2 or 3, wherein the ultrasonic treatment is performed for 10 to 30 minutes in step S3, the flexible substrate has a thickness of 100 μm, the sensitive layer has a thickness of 15 μm, and the conductive layer has a thickness of 40 to 50nm in step S4.
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| CN114459333B (en) * | 2022-01-26 | 2023-03-28 | 浙江大学 | Tensile strain sensor based on porous flexible material |
| CN114440760B (en) * | 2022-01-26 | 2023-01-10 | 浙江大学 | Flexible tensile strain sensor |
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| US7888700B2 (en) * | 2007-03-08 | 2011-02-15 | Eastman Kodak Company | Quantum dot light emitting device |
| JP2010091351A (en) * | 2008-10-07 | 2010-04-22 | Yamaha Corp | Method of manufacturing mems sensor |
| KR101737525B1 (en) * | 2015-02-27 | 2017-05-18 | 포항공과대학교 산학협력단 | The high-sensitive strain sensor using nano-crack and the process of that and the strain sensing system comprising that |
| CN105627905B (en) * | 2016-02-24 | 2019-06-18 | 清华大学 | A kind of metallic film flexibility strain transducer and preparation method thereof |
| CN105866175B (en) * | 2016-03-28 | 2018-10-19 | 上海交通大学 | Printable flexible ammonia gas sensor of one kind and preparation method thereof |
| CN105783697B (en) * | 2016-05-18 | 2018-08-14 | 郑州大学 | Flexible strain transducer with crack structtire and preparation method thereof |
| CN105925963B (en) * | 2016-05-23 | 2018-04-06 | 厦门大学 | A kind of dry mediation gold nano grain self assembly prepares the method and its application of gold substrate |
| CN106959071B (en) * | 2017-01-19 | 2019-04-26 | 吉林大学 | A kind of bionical strain perceptual structure and forming method thereof |
| CN108020157A (en) * | 2017-11-21 | 2018-05-11 | 北京科技大学 | A kind of low cost, high-performance human motion sensor and preparation method thereof |
| CN108267078B (en) * | 2018-03-18 | 2020-01-14 | 吉林大学 | Flexible wearable resistance-type strain sensor and preparation method thereof |
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