CN115678060A - Dielectric film, capacitive pressure sensor and preparation method thereof - Google Patents
Dielectric film, capacitive pressure sensor and preparation method thereof Download PDFInfo
- Publication number
- CN115678060A CN115678060A CN202211016500.5A CN202211016500A CN115678060A CN 115678060 A CN115678060 A CN 115678060A CN 202211016500 A CN202211016500 A CN 202211016500A CN 115678060 A CN115678060 A CN 115678060A
- Authority
- CN
- China
- Prior art keywords
- dielectric film
- pressure sensor
- capacitive pressure
- mixed solution
- pdms
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000002360 preparation method Methods 0.000 title claims abstract description 18
- 239000002245 particle Substances 0.000 claims abstract description 85
- 239000004205 dimethyl polysiloxane Substances 0.000 claims abstract description 73
- 229920000435 poly(dimethylsiloxane) Polymers 0.000 claims abstract description 73
- 239000011259 mixed solution Substances 0.000 claims abstract description 70
- 238000000034 method Methods 0.000 claims abstract description 45
- 239000000758 substrate Substances 0.000 claims abstract description 34
- 238000000576 coating method Methods 0.000 claims abstract description 19
- 239000011248 coating agent Substances 0.000 claims abstract description 18
- 238000010438 heat treatment Methods 0.000 claims abstract description 18
- 238000004519 manufacturing process Methods 0.000 claims abstract description 16
- 239000000243 solution Substances 0.000 claims abstract description 13
- 238000002156 mixing Methods 0.000 claims abstract description 9
- 235000013870 dimethyl polysiloxane Nutrition 0.000 claims abstract 7
- CXQXSVUQTKDNFP-UHFFFAOYSA-N octamethyltrisiloxane Chemical compound C[Si](C)(C)O[Si](C)(C)O[Si](C)(C)C CXQXSVUQTKDNFP-UHFFFAOYSA-N 0.000 claims abstract 7
- 238000004987 plasma desorption mass spectroscopy Methods 0.000 claims abstract 7
- 239000010408 film Substances 0.000 claims description 136
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 38
- 229910052710 silicon Inorganic materials 0.000 claims description 38
- 239000010703 silicon Substances 0.000 claims description 38
- 238000001723 curing Methods 0.000 claims description 15
- 239000010409 thin film Substances 0.000 claims description 3
- 238000001029 thermal curing Methods 0.000 claims 1
- 230000035945 sensitivity Effects 0.000 abstract description 39
- 238000010146 3D printing Methods 0.000 abstract description 7
- 230000008569 process Effects 0.000 abstract description 7
- 238000010041 electrostatic spinning Methods 0.000 abstract description 5
- 239000004800 polyvinyl chloride Substances 0.000 description 19
- 229920000915 polyvinyl chloride Polymers 0.000 description 19
- 239000000463 material Substances 0.000 description 13
- 238000004528 spin coating Methods 0.000 description 7
- 230000000903 blocking effect Effects 0.000 description 5
- 230000008859 change Effects 0.000 description 5
- 239000004433 Thermoplastic polyurethane Substances 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 229920002803 thermoplastic polyurethane Polymers 0.000 description 3
- 230000009471 action Effects 0.000 description 2
- 229920001971 elastomer Polymers 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- AMGQUBHHOARCQH-UHFFFAOYSA-N indium;oxotin Chemical compound [In].[Sn]=O AMGQUBHHOARCQH-UHFFFAOYSA-N 0.000 description 2
- 238000004321 preservation Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000001680 brushing effect Effects 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 238000007598 dipping method Methods 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 239000000806 elastomer Substances 0.000 description 1
- 238000013007 heat curing Methods 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- -1 polydimethylsiloxane Polymers 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 229920002725 thermoplastic elastomer Polymers 0.000 description 1
Images
Landscapes
- Measuring Fluid Pressure (AREA)
Abstract
The invention provides a dielectric film, a capacitive pressure sensor and a preparation method thereof; the preparation method of the dielectric film comprises the following steps: mixing the thermal expansion particles with the PDMS solution to obtain a mixed solution; and coating the mixed solution on the surface of the substrate, and heating and curing to form a dielectric film on the surface of the substrate, wherein the dielectric film comprises a PDMS film layer and hollow hemispherical bulges which protrude out of the surface of the PDMS film layer and are formed by thermal expansion particles. Compared with the traditional preparation methods of the capacitive pressure sensor such as a mold method, a 3D printing method, an electrostatic spinning method and the like, the preparation method disclosed by the invention is very simple in process, low in cost, high in repeatability and capable of realizing large-area production, and the prepared capacitive pressure sensor is high in sensitivity.
Description
Technical Field
The invention relates to the technical field of sensors, in particular to a dielectric film, a capacitive pressure sensor and a preparation method thereof.
Background
Due to the unique advantages of the flexible capacitive pressure sensor, the flexible capacitive pressure sensor gradually obtains wide attention and preliminary application in important fields of wearable electronic equipment, human-computer interaction, aircraft intelligent skin and the like, and shows a huge application prospect. However, although relevant research is continuously intensive at home and abroad, the whole technology is not mature enough, and the problems of complex preparation process, high cost, low sensitivity and the like exist.
The traditional preparation method of the flexible capacitive pressure sensor mainly comprises a mold method, a 3D printing method and an electrostatic spinning method. The mold method has complex preparation process and high cost, and cannot prepare in a large area; the 3D printing method has limited printable materials, many materials cannot be directly printed and formed through 3D printing, and the microstructure on the surface of the capacitive pressure sensor cannot be realized through a 3D printing technology, so that the sensitivity of the sensor is low; the electrostatic spinning method has complex process, is difficult to realize large-area production, and has strong randomness and poor repeatability.
Disclosure of Invention
Therefore, a dielectric film, a capacitive pressure sensor and a preparation method thereof with high sensitivity, low cost and simple preparation process are needed to be provided.
The technical scheme provided by the invention is as follows:
according to an aspect of the present invention, there is provided a method of preparing a dielectric thin film, including the steps of:
mixing the thermal expansion particles with the PDMS solution to obtain a mixed solution; and
and coating the mixed solution on the surface of a substrate, and heating and curing to form the dielectric film on the surface of the substrate, wherein the dielectric film comprises a PDMS film layer and hollow hemispherical bulges which protrude out of the surface of the PDMS film layer and are formed by the thermal expansion particles.
In some of these embodiments, the thermally-expansive particles are one or more of PVC thermally-expansive particles, TPU thermally-expansive particles, and TPR thermally-expansive particles.
In some embodiments, the heating and curing temperature is 100-160 ℃, and the holding time is 30-60 min.
In some embodiments, the coating thickness of the mixed solution on the surface of the substrate is 50 μm to 200 μm.
In some embodiments, the content of the thermal expansion particles in the mixed solution is 1% to 30% by mass.
In some of these embodiments, the thermally expandable particles have a particle size of 10 μm to 50 μm.
In some of these embodiments, the substrate is a silicon wafer.
According to another aspect of the present invention, there is also provided a dielectric film prepared by the method for preparing a dielectric film according to the present invention.
According to another aspect of the present invention, there is also provided a method for manufacturing a capacitive pressure sensor, including the steps of:
providing the dielectric film of the present invention; and
and arranging electrodes on two surfaces of the dielectric film respectively.
In some of these embodiments, the electrode is a flexible electrode.
According to another aspect of the present invention, there is also provided a capacitive pressure sensor, which is prepared by the above method for preparing a capacitive pressure sensor.
In some embodiments, one of the electrodes is in contact with the hollow hemispherical protrusion in the dielectric film in a natural state and is not in contact with the PDMS film layer in the dielectric film.
Compared with the prior art, the invention has the following beneficial effects:
according to the preparation method of the dielectric film and the capacitive pressure sensor, the mixed solution of the thermal expansion particles and the PDMS solution is coated on the substrate, and then heating and curing are carried out, so that the dielectric film can be prepared on the surface of the substrate; the PDMS forms a film layer in the heating and curing process, the thermal expansion particles expand when heated, and because one surface of the PDMS is blocked by the base material, the thermal expansion particles form hollow hemispherical bulges on the surface of the PDMS film layer, which is deviated from the base material, and the hollow hemispherical bulges protrude out of the surface of the PDMS film layer; the PDMS in the dielectric film and the thermal expansion particles with the hollow hemispherical bulges are of an integrally formed structure; electrodes are respectively arranged on two surfaces of the dielectric film, and the capacitive pressure sensor can be obtained; compared with the traditional die method, 3D printing method, electrostatic spinning method and the like, the preparation method provided by the invention has the advantages that the process is very simple, the cost is low, the repeatability is high, the large-area production can be realized, and the sensitivity of the prepared capacitive pressure sensor is higher.
Drawings
Fig. 1 is a schematic structural diagram of a capacitive pressure sensor according to an embodiment of the present invention;
FIG. 2 is a schematic structural diagram of a capacitive pressure sensor according to an embodiment of the present invention when the capacitive pressure sensor is under pressure;
FIG. 3 is a pictorial view of a capacitive pressure sensor in accordance with an embodiment of the present invention;
fig. 4 is a sensitivity test curve of the capacitive pressure sensor of embodiment 1 of the present invention;
fig. 5 is a sensitivity test curve of the capacitive pressure sensor of embodiment 2 of the present invention;
fig. 6 is a sensitivity test curve of the capacitive pressure sensor according to embodiment 3 of the present invention;
fig. 7 is a sensitivity test curve of the capacitive pressure sensor according to embodiment 4 of the present invention;
fig. 8 is a sensitivity test curve of the capacitive pressure sensor according to embodiment 5 of the present invention.
Description of reference numerals:
10. a capacitive pressure sensor; 11. a dielectric film; 12. an electrode; 111. a PDMS membrane layer; 112. a hollow hemispherical bulge.
Detailed Description
The present invention will be described in detail with reference to the accompanying drawings, which illustrate embodiments of the present invention. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Unless otherwise specifically stated, various raw materials, reagents, instruments, equipment and the like used in the present invention are commercially available or can be prepared by existing methods.
Some embodiments of the present invention provide a method of preparing a dielectric thin film 11, the method including steps S100 and S200 of:
step S100: the thermally expandable particles were mixed with a PDMS (polydimethylsiloxane) solution to obtain a mixed solution.
In the invention, thermal expansion particles are mixed with PDMS solution to form mixed solution containing the thermal expansion particles and PDMS, which is used for preparing the dielectric film 11 of the capacitive pressure sensor 10.
Specifically, the thermally-expandable particles may be a mixture of one or more of PVC (polyvinyl chloride) thermally-expandable particles, TPU (thermoplastic polyurethane elastomer rubber) thermally-expandable particles, and TPR (thermoplastic rubber SBS blend modified material) thermally-expandable particles. PVC heat expandable particles are preferably used. The thermally expandable particles absorb heat to expand when heated, and the volume of the thermally expandable particles is increased, and hollow structures are formed in the thermally expandable particles.
In some embodiments, the content of the thermally expandable particles in the mixed solution is controlled within a range of 1% to 30% by mass. The content of the thermally expandable particles in the mixed solution determines the number of the hollow hemispherical protrusions 112 in the dielectric film 11 after being heated and cured, and thus affects the sensitivity of the capacitive pressure sensor 10. It has been found that when the mass percentage of the thermally expandable particles in the mixed solution is controlled to be 1% to 30%, the capacitive pressure sensor 10 has a higher sensitivity. When the content of the thermal expansion particles in the mixed solution is too small, the number of the hollow hemispherical protrusions 112 expanded by the thermal expansion particles is small, the sensor sensitivity is high, but the range is too small, the contact area with the electrode 12 is too small, and the reliability is low; when the content of the thermal expansion particles is too much, the thermal expansion particles are not easy to disperse and easy to agglomerate, and the surface structure is difficult to be uniform by the existing process.
In some of these embodiments, the thermally expandable particles have a particle size of 10 μm to 50 μm. The size of the thermal expansion particles can affect the size and height of the hollow hemispherical protrusions 112 in the dielectric film 11 after being heated and cured, and further can affect the sensitivity of the capacitive pressure sensor 10. Experimental studies have found that when the particle diameter of the thermally expandable particles is controlled within a range of 10 μm to 50 μm, the capacitive pressure sensor 10 can be made to have high sensitivity. If the particle size of the thermal expansion particles is too small, the thermal expansion particles cannot form the hollow hemispherical protrusions 112 on the surface of the PDMS film layer after expansion; if the particle size of the thermal expansion particles is too large, it is not easy to manufacture, and the uniformity of the size of the hollow hemispherical protrusions 112 after thermal expansion is poor.
Step S200: and coating the mixed solution on the surface of the substrate, and heating and curing to form a dielectric film 11 on the surface of the substrate, wherein the dielectric film 11 comprises a PDMS film layer 111 and hollow hemispherical bulges 112 formed by thermal expansion particles and protruding out of the surface of the PDMS film layer 111.
After preparing a mixed solution of thermal expansion particles and a PDMS solution, coating the mixed solution on the surface of a base material, putting the base material and the mixed solution coated on the base material into a vacuum oven for heating and heat preservation, so that PDMS in the mixed solution on the surface of the base material is cured to form a PDMS film layer 111, and meanwhile, the thermal expansion particles in the mixed solution are heated and expanded; because the mixed solution is coated on the base material, one surface of the thermal expansion particles is blocked by the base material, and therefore the thermal expansion particles expand towards the side, away from the base material, of the PDMS film layer 111 when being heated and expanded, and therefore the hollow hemispherical protrusions 112 are formed on the side, away from the base material, of the dielectric film 11; the hollow hemispherical protrusions 112 protrude from the surface of the PDMS film layer 111, and are integrally formed with the PDMS film layer 111. And taking down the surface of the dielectric film 11 layer substrate after heating and curing, thus obtaining the single dielectric film 11.
When the capacitive pressure sensor 10 is formed by bonding the electrodes 12 on the dielectric film 11, at least one electrode 12 is in contact with the hollow hemispherical convex 112, and the contact area is small and easy to deform. When pressure acts on the sensor, the hollow hemispherical convex 112 can generate larger deformation, so that the polar distance between the two electrodes 12 of the capacitive pressure sensor 10 is rapidly reduced, the capacitance value of the sensor is rapidly increased, and the capacitive pressure sensor 10 has higher sensitivity.
Specifically, the mixed solution may be applied to the surface of the substrate by various conventional coating methods. For example, the mixed solution may be applied to the surface of the substrate by brushing, dipping, spraying, spin coating, or the like. The coating is preferably carried out in a spin coating mode, the operation is simple, the coating thickness is easy to control, and the consistency of the coating thickness is good. The substrate may be made of a silicon wafer or the like.
In some embodiments, the temperature of heating and curing is controlled to be 100-160 ℃, and the time of heat preservation is controlled to be 30-60 min. It is found that under the conditions of the heating curing temperature and the holding time, the thermal expansion particles in the mixed solution coated on the surface of the substrate can be fully expanded, so that the hollow hemispherical protrusions 112 can be better formed, and the prepared capacitive pressure sensor 10 has higher sensitivity.
In some embodiments, the coating thickness of the mixed solution on the surface of the substrate is controlled to be 50 μm to 200 μm. The coating thickness of the mixed solution on the surface of the substrate is not too large or too small, and when the coating thickness of the mixed solution is too large, the thickness of the film layer formed on the surface of the substrate after heating and curing is larger, so that the height of the thermal expansion particles protruding out of the surface of the PDMS film layer 111 is reduced, and a hollow hemispherical microstructure cannot be formed on the surface of the PDMS film layer 111, so that the deformation capability of the hollow hemispherical protrusions 112 under the action of pressure is reduced, and the sensitivity of the capacitive pressure sensor 10 is reduced; when the thickness of the mixed solution is too small, the mechanical strength of the film is low after the thermal expansion particles expand by heating, and the tensile deformation range of the sensor is further reduced.
Some embodiments of the present invention provide a dielectric film 11, and the dielectric film 11 is prepared by the method for preparing the dielectric film 11 according to the present invention. The dielectric film 11 includes a PDMS film 111, a flat surface of one surface of the PDMS film 111, and a hollow hemispherical protrusion 112 protruding from the other surface of the PDMS film 111, wherein the hollow hemispherical protrusion 112 is formed by thermal expansion of thermal expansion particles, and the hollow hemispherical protrusion 112 and the PDMS film 111 are integrally formed.
When the capacitive pressure sensor 10 is formed by using the dielectric film 11, two electrodes 12 are respectively bonded on the upper and lower surfaces of the dielectric film 11, wherein one electrode 12 is in contact with the plane of the PDMS film layer 111 of the dielectric film 11, and the other electrode 12 is in contact with the hollow hemispherical protrusion 112 on the other surface of the dielectric film 11. When the electrode 12 contacting with the hollow hemispherical convex 112 is pressed, the hollow hemispherical convex 112 can generate larger deformation, so that the capacitance value of the sensor is rapidly increased, and the capacitance pressure sensor 10 has higher sensitivity.
Some embodiments of the present invention provide a method for manufacturing a capacitive pressure sensor 10, which includes steps S300 and S400 as follows:
step S300: the dielectric film 11 of the present invention is provided.
The dielectric film 11 is prepared by the method for preparing the dielectric film 11 of the present invention. Specifically, the preparation method comprises the following steps: mixing the thermal expansion particles with the PDMS solution to obtain a mixed solution; and coating the mixed solution on the surface of the substrate, and heating and curing to form a dielectric film 11 on the surface of the substrate, wherein the dielectric film 11 comprises a PDMS film layer 111 and hollow hemispherical bulges 112 formed by thermal expansion particles and protruding out of the surface of the PDMS film layer 111. The dielectric film 11 is separated from the substrate, and the dielectric film 11 alone is obtained.
Step S400: electrodes 12 are provided on both surfaces of the dielectric film 11, respectively.
Specifically, one surface (the surface contacting the substrate) of the dielectric film 11 is a plane, and the other surface opposite to the plane has a hollow hemispherical protrusion 112 protruding from the surface of the PDMS film layer 111. One of the electrodes 12 is bonded to the flat surface of the dielectric film 11, and the other electrode 12 is bonded to the hollow hemispheric protrusion 112 on the other side of the dielectric film 11. Thus, when the capacitive pressure sensor 10 is pressed by the electrode 12 contacting the hollow hemispherical protrusion 112, the hollow hemispherical protrusion 112 can be deformed greatly, so that the capacitance of the sensor is increased rapidly, and the capacitive pressure sensor 10 has high sensitivity.
In some embodiments, the electrodes 12 are flexible electrodes, so that the flexible capacitive pressure sensor 10 can be manufactured. Specifically, the flexible electrode can adopt an indium tin oxide flexible electrode commonly used in a traditional flexible sensor, such as an ITO-PET conductive film.
In general, the method for manufacturing the dielectric film 11 and the capacitive pressure sensor 10 of the present invention only needs to coat the thermal expansion particles and the PDMS mixed solution on the substrate, and heat-cure the mixture, so as to form the dielectric film 11 on the surface of the substrate. In the heating and curing process, curing PDMS in the mixed solution on the surface of the substrate to form a PDMS film 111, forming hollow hemispherical protrusions 112 protruding out of the surface of the PDMS film 111 by thermal expansion of the thermal expansion particles, and bonding electrodes 12 (such as flexible electrodes) on two sides of the dielectric film 11 to obtain the capacitive pressure sensor 10; compared with the traditional die method, 3D printing method, electrostatic spinning method and the like, the preparation method provided by the invention has the advantages of simple process, low cost, high repeatability, capability of realizing large-area production and high sensitivity of the prepared capacitive pressure sensor 10.
Referring to fig. 1, some embodiments of the present invention further provide a capacitive pressure sensor 10, where the capacitive pressure sensor 10 includes a dielectric film 11 and two electrodes 12.
Wherein, one surface of the dielectric film 11 has a hollow hemispherical convex 112; one of the electrodes 12 is bonded to one surface of the dielectric film 11; another electrode 12 is bonded to the other surface of the dielectric film 11. The capacitive pressure sensor 10 is prepared by the preparation method of the capacitive pressure sensor 10. The electrodes 12 are preferably flexible electrodes, such as indium tin oxide flexible electrodes.
In the capacitive pressure sensor 10, one surface of the dielectric film 11 has the hollow hemispherical protrusion 112; one of the electrodes 12 is in contact with the hollow hemispherically-shaped protrusion 112 when the electrode 12 is bonded to the dielectric film 11; when pressure acts on the capacitive pressure sensor 10, the hollow hemispherical protrusion 112 on the dielectric film 11 deforms under the action of the pressure, so that the electrode 12 in contact with the hollow hemispherical protrusion 112 is displaced, the polar distance between the two electrodes 12 is reduced, the capacitance value is increased, and the sensitivity of the capacitive pressure sensor 10 is improved.
Specifically, in the capacitive pressure sensor 10, one electrode 12 is bonded to the upper surface of the dielectric film 11, and the other electrode 12 is bonded to the lower surface of the dielectric film 11. One electrode 12 on the upper surface is in contact with the hollow hemispherical protrusions 112 in the dielectric film 11 in a natural state (non-compressed state) and is not in contact with the surface of the PDMS film layer 111 in the dielectric film 11. That is, a certain gap exists between the electrode 12 and the surface of the PDMS film 111 in a natural state, which allows room for the deformation of the hollow hemispheric protrusion 112 and the displacement of the electrode 12 after the electrode 12 is pressed. The structure of the capacitive pressure sensor 10 is schematically shown in fig. 1, the schematic diagram of the capacitive pressure sensor after being subjected to pressure is shown in fig. 2, and the physical photograph thereof is shown in fig. 3.
The present invention will be further described with reference to specific examples and comparative examples, which should not be construed as limiting the scope of the present invention.
Example 1:
a method of making a flexible capacitive pressure sensor 10, comprising the steps of:
(1) Uniformly mixing PVC thermal expansion particles with the particle size of 10-20 microns with the PDMS solution to obtain a mixed solution, wherein the mass percentage of the PVC thermal expansion particles in the mixed solution is 10%;
(2) Pouring the mixed solution on one side surface of a silicon wafer, uniformly coating the mixed solution on the surface of the silicon wafer by a spin coating method, and controlling the thickness of the mixed solution on the surface of the silicon wafer to be 50 microns;
(3) Putting the silicon wafer coated with the mixed solution into a vacuum oven, preserving the heat for 60min at 100 ℃, enabling PDMS in the mixed solution on the surface of the silicon wafer to be cured to form a PDMS film layer 111, enabling PVC thermal expansion particles to expand under heating, forming a hollow hemispherical bulge 112 on the surface of the PDMS film layer 111 departing from the silicon wafer due to the blocking of the silicon wafer, wherein the hollow hemispherical bulge 112 and the PDMS film layer 111 are of an integrally formed structure, and the dielectric film 11 is obtained;
(4) The dielectric film 11 is separated from the substrate, and a TIO-PET conductive film is bonded to each of the upper and lower surfaces of the dielectric film 11 as a flexible electrode, thereby forming the flexible capacitive pressure sensor 10.
The sensitivity of the flexible capacitive pressure sensor 10 is detected by adopting an impedance analyzer to measure the change relation between the capacitance value of the capacitive pressure sensor 10 and the pressure in real time so as to calculate the sensitivity S of the pressure sensor,
the sensitivity of the capacitive pressure sensor 10 of the present embodiment is shown in fig. 4. In fig. 4, the abscissa is the pressure P; the ordinate is Δ C/P, i.e. the sensitivity S. As can be seen from fig. 4, the capacitive pressure sensor 10 has a high sensitivity.
Example 2:
a method of making a flexible capacitive pressure sensor 10, comprising the steps of:
(1) Uniformly mixing PVC particles with the particle size of 10-20 microns with the PDMS solution to obtain a mixed solution, wherein the mass percentage of the PVC particles in the mixed solution is 10%;
(2) Pouring the mixed solution on one side surface of a silicon wafer, uniformly coating the mixed solution on the surface of the silicon wafer by a spin coating method, and controlling the thickness of the mixed solution on the surface of the silicon wafer to be 100 micrometers;
(3) Putting the silicon wafer coated with the mixed solution into a vacuum oven, preserving the heat at 160 ℃ for 30min, so that PDMS in the mixed solution on the surface of the silicon wafer is cured to form a PDMS film layer 111, meanwhile, PVC thermal expansion particles expand under heating, due to the blocking of the silicon wafer, a hollow hemispherical bulge 112 is formed on the surface of the PDMS film layer 111, which is far away from the silicon wafer, and the hollow hemispherical bulge 112 and the PDMS film layer 111 are of an integrally formed structure, namely the dielectric film 11;
(4) The dielectric film 11 is separated from the substrate, and a TIO-PET conductive film is bonded as a flexible electrode on each of the upper and lower surfaces of the dielectric film 11, thereby forming the flexible capacitive pressure sensor 10.
And measuring the change relation between the capacitance value of the capacitive pressure sensor 10 and the pressure in real time by using an impedance analyzer, thereby calculating the sensitivity S of the pressure sensor. The sensitivity of the capacitive pressure sensor 10 of the present embodiment is shown in fig. 5. As can be seen from fig. 5, the capacitive pressure sensor 10 has a high sensitivity.
Example 3:
a method of making a flexible capacitive pressure sensor 10, comprising the steps of:
(1) Uniformly mixing PVC particles with the particle size of 10-20 microns with the PDMS solution to obtain a mixed solution, wherein the mass percentage of the PVC particles in the mixed solution is 10%;
(2) Pouring the mixed solution on one side surface of a silicon wafer, uniformly coating the mixed solution on the surface of the silicon wafer by a spin coating method, and controlling the thickness of the mixed solution on the surface of the silicon wafer to be 200 mu m;
(3) Putting the silicon wafer coated with the mixed solution into a vacuum oven, preserving the heat for 60min at 100 ℃, enabling PDMS in the mixed solution on the surface of the silicon wafer to be cured to form a PDMS film layer 111, enabling PVC thermal expansion particles to expand under heating, forming a hollow hemispherical bulge 112 on the surface of the PDMS film layer 111 departing from the silicon wafer due to the blocking of the silicon wafer, wherein the hollow hemispherical bulge 112 and the PDMS film layer 111 are of an integrally formed structure, and the dielectric film 11 is obtained;
(4) The dielectric film 11 is separated from the substrate, and a TIO-PET conductive film is bonded as a flexible electrode on each of the upper and lower surfaces of the dielectric film 11, thereby forming the flexible capacitive pressure sensor 10.
And measuring the change relation between the capacitance value of the capacitive pressure sensor 10 and the pressure in real time by using an impedance analyzer, thereby calculating the sensitivity S of the pressure sensor. The sensitivity of the capacitive pressure sensor 10 of the present embodiment is shown in fig. 6. As can be seen from fig. 6, the capacitive pressure sensor 10 has a high sensitivity.
Example 4:
a method of making a flexible capacitive pressure sensor 10, comprising the steps of:
(1) Uniformly mixing PVC particles with the particle size of 10-20 microns with the PDMS solution to obtain a mixed solution, wherein the mass percentage of the PVC particles in the mixed solution is 30%;
(2) Pouring the mixed solution on one side surface of a silicon wafer, uniformly coating the mixed solution on the surface of the silicon wafer by a spin coating method, and controlling the thickness of the mixed solution on the surface of the silicon wafer to be 100 micrometers;
(3) Putting the silicon wafer coated with the mixed solution into a vacuum oven, preserving the heat for 60min at 100 ℃,
curing PDMS in the mixed solution on the surface of the silicon wafer to form a PDMS film layer 111, wherein PVC thermal expansion particles expand when heated, and due to the blocking of the silicon wafer, a hollow hemispherical protrusion 112 is formed on the surface of the PDMS film layer 111, which is away from the silicon wafer, wherein the hollow hemispherical protrusion 112 and the PDMS film layer 111 are in an integrally formed structure, namely the dielectric film 11;
(4) The dielectric film 11 is separated from the substrate, and a TIO-PET conductive film is bonded to each of the upper and lower surfaces of the dielectric film 11 as a flexible electrode, thereby forming the flexible capacitive pressure sensor 10.
And measuring the change relation between the capacitance value of the capacitive pressure sensor 10 and the pressure in real time by using an impedance analyzer, thereby calculating the sensitivity S of the pressure sensor. The sensitivity of the capacitive pressure sensor 10 of the present embodiment is shown in fig. 7. As can be seen from fig. 7, the capacitive pressure sensor 10 has a high sensitivity.
Example 5:
a method of making a flexible capacitive pressure sensor 10, comprising the steps of:
(1) Uniformly mixing PVC particles with the particle size of 30-50 microns with a PDMS solution to obtain a mixed solution, wherein the mass percentage of the PVC particles in the mixed solution is 10%;
(2) Pouring the mixed solution on one side surface of a silicon wafer, uniformly coating the mixed solution on the surface of the silicon wafer by a spin coating method, and controlling the thickness of the mixed solution on the surface of the silicon wafer to be 100 micrometers;
(3) Putting the silicon wafer coated with the mixed solution into a vacuum oven, preserving the heat for 60min at 100 ℃,
curing PDMS in the mixed solution on the surface of the silicon wafer to form a PDMS film layer 111, wherein PVC thermal expansion particles expand when heated, and due to the blocking of the silicon wafer, a hollow hemispherical protrusion 112 is formed on the surface of the PDMS film layer 111, which is away from the silicon wafer, wherein the hollow hemispherical protrusion 112 and the PDMS film layer 111 are in an integrally formed structure, namely the dielectric film 11;
(4) The dielectric film 11 is separated from the substrate, and a TIO-PET conductive film is bonded as a flexible electrode on each of the upper and lower surfaces of the dielectric film 11, thereby forming the flexible capacitive pressure sensor 10.
And measuring the change relation between the capacitance value of the capacitive pressure sensor 10 and the pressure in real time by using an impedance analyzer, thereby calculating the sensitivity S of the pressure sensor. The sensitivity of the capacitive pressure sensor 10 of the present embodiment is shown in fig. 8. As can be seen from fig. 8, the capacitive pressure sensor 10 has a high sensitivity.
The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.
Claims (12)
1. A method for preparing a dielectric film, comprising the steps of:
mixing the thermal expansion particles with the PDMS solution to obtain a mixed solution; and
and coating the mixed solution on the surface of a substrate, and heating and curing to form the dielectric film on the surface of the substrate, wherein the dielectric film comprises a PDMS film layer and hollow hemispherical bulges which protrude out of the surface of the PDMS film layer and are formed by the thermal expansion particles.
2. The method of claim 1, wherein the thermally-expansive particles are one or more of PVC thermally-expansive particles, TPU thermally-expansive particles, and TPR thermally-expansive particles.
3. The method of claim 1, wherein the temperature for the thermal curing is 100-160 ℃ and the holding time is 30-60 min.
4. The method of claim 1, wherein the mixed solution is applied to the surface of the substrate to a thickness of 50 μm to 200 μm.
5. The method of claim 1, wherein the mixed solution contains the thermally expandable particles in an amount of 1 to 30% by mass.
6. The method of preparing a dielectric thin film according to any one of claims 1 to 5, wherein the thermally expandable particles have a particle size of 10 μm to 50 μm.
7. The method of producing a dielectric film according to any one of claims 1 to 5, wherein the substrate is a silicon wafer.
8. A dielectric film produced by the method for producing a dielectric film according to any one of claims 1 to 6.
9. A preparation method of a capacitive pressure sensor is characterized by comprising the following steps:
providing a dielectric film according to claim 8; and
and arranging electrodes on two surfaces of the dielectric film respectively.
10. The method of making a capacitive pressure sensor of claim 9 wherein the electrode is a flexible electrode.
11. A capacitive pressure sensor, characterized in that it is produced by a method for producing a capacitive pressure sensor according to any one of claims 9 or 10.
12. The capacitive pressure sensor of claim 11, wherein one of the electrodes is in contact with the hollow hemispherical protrusion in the dielectric film in a natural state and is not in contact with the PDMS film layer in the dielectric film.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211016500.5A CN115678060B (en) | 2022-08-24 | 2022-08-24 | Dielectric film, capacitive pressure sensor and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211016500.5A CN115678060B (en) | 2022-08-24 | 2022-08-24 | Dielectric film, capacitive pressure sensor and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115678060A true CN115678060A (en) | 2023-02-03 |
| CN115678060B CN115678060B (en) | 2024-05-17 |
Family
ID=85061468
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211016500.5A Active CN115678060B (en) | 2022-08-24 | 2022-08-24 | Dielectric film, capacitive pressure sensor and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115678060B (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009198482A (en) * | 2008-01-24 | 2009-09-03 | Tokai Rubber Ind Ltd | Sensor thin film, manufacturing method thereof and deformation sensor |
| CN110146198A (en) * | 2019-05-22 | 2019-08-20 | 厦门大学 | A kind of flexibility self energizing pressure sensor |
| CN114034416A (en) * | 2021-10-19 | 2022-02-11 | 中国电子产品可靠性与环境试验研究所（（工业和信息化部电子第五研究所）（中国赛宝实验室）） | Flexible capacitive sensor and preparation method thereof |
-
2022
- 2022-08-24 CN CN202211016500.5A patent/CN115678060B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009198482A (en) * | 2008-01-24 | 2009-09-03 | Tokai Rubber Ind Ltd | Sensor thin film, manufacturing method thereof and deformation sensor |
| CN110146198A (en) * | 2019-05-22 | 2019-08-20 | 厦门大学 | A kind of flexibility self energizing pressure sensor |
| CN114034416A (en) * | 2021-10-19 | 2022-02-11 | 中国电子产品可靠性与环境试验研究所（（工业和信息化部电子第五研究所）（中国赛宝实验室）） | Flexible capacitive sensor and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115678060B (en) | 2024-05-17 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109945999B (en) | Preparation method of flexible film pressure sensor | |
| CN108318161B (en) | Wearable pressure sensor and manufacturing method thereof | |
| CN101059380B (en) | Flexible capacitance type touch sensor production method | |
| Ma et al. | A highly sensitive and flexible capacitive pressure sensor based on a micro-arrayed polydimethylsiloxane dielectric layer | |
| CN106482628B (en) | A kind of large deformation flexible strain transducer and preparation method thereof | |
| CN110146198B (en) | Flexible self-powered pressure sensor | |
| CN109115376A (en) | A kind of condenser type pliable pressure sensor and preparation method thereof | |
| CN110726364B (en) | Flexible strain sensor with strain isolation effect | |
| CN114034416A (en) | Flexible capacitive sensor and preparation method thereof | |
| CN108515694B (en) | Flexible pressure sensor chip based on 3D printing technology and manufacturing method thereof | |
| WO2021253278A1 (en) | Touch sensor, manufacturing method, and intelligent device comprising touch sensor | |
| CN113340483A (en) | Flexible mechanical sensor of bionic microstructure and preparation method thereof | |
| CN111732744B (en) | Method for preparing flexible strain sensor by utilizing biaxial tension technology | |
| CN114705334B (en) | Linear piezoresistive touch sensor and preparation method thereof | |
| CN111024272A (en) | Preparation method of capacitive flexible sensor | |
| CN206269946U (en) | Pressure sensor | |
| CN112326074A (en) | Touch sensor, preparation method and intelligent device comprising touch sensor | |
| CN113218543A (en) | Flexible pressure sensor, dielectric layer thereof and preparation method of dielectric layer | |
| CN111473891B (en) | Composite dielectric layer flexible capacitive touch sensor based on open-pore-closed pore structure and preparation method thereof | |
| CN216284043U (en) | High-linearity flexible pressure sensor with adjustable sensitivity | |
| CN115219078A (en) | Piezoresistive sensor based on locust bean gum hydrogel and preparation method and application thereof | |
| CN113138042B (en) | Capacitive flexible pressure sensor of PDMS-PS polymer dielectric and manufacturing process thereof | |
| CN115678060A (en) | Dielectric film, capacitive pressure sensor and preparation method thereof | |
| CN114199424A (en) | Piezoresistive sensor and preparation process thereof | |
| CN114485376A (en) | Preparation method of low-temperature flexible strain sensor |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |