CN116380301A - Flexible capacitive pressure sensor and method based on porous structure and microstructure - Google Patents
Flexible capacitive pressure sensor and method based on porous structure and microstructure Download PDFInfo
- Publication number
- CN116380301A CN116380301A CN202310525933.1A CN202310525933A CN116380301A CN 116380301 A CN116380301 A CN 116380301A CN 202310525933 A CN202310525933 A CN 202310525933A CN 116380301 A CN116380301 A CN 116380301A
- Authority
- CN
- China
- Prior art keywords
- porous structure
- microstructure
- foam layer
- layer
- pressure sensor
- 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.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims abstract description 19
- 239000006260 foam Substances 0.000 claims abstract description 59
- 229920001971 elastomer Polymers 0.000 claims abstract description 32
- 239000000806 elastomer Substances 0.000 claims abstract description 32
- 239000002390 adhesive tape Substances 0.000 claims abstract description 19
- 239000006261 foam material Substances 0.000 claims abstract description 15
- 239000000463 material Substances 0.000 claims abstract description 15
- 229920001940 conductive polymer Polymers 0.000 claims abstract description 14
- 238000006116 polymerization reaction Methods 0.000 claims abstract description 13
- 238000010438 heat treatment Methods 0.000 claims abstract description 9
- 239000011248 coating agent Substances 0.000 claims abstract description 6
- 238000000576 coating method Methods 0.000 claims abstract description 6
- 230000003647 oxidation Effects 0.000 claims abstract description 5
- 238000007254 oxidation reaction Methods 0.000 claims abstract description 5
- 238000004806 packaging method and process Methods 0.000 claims abstract description 5
- 239000004433 Thermoplastic polyurethane Substances 0.000 claims description 18
- 229920002803 thermoplastic polyurethane Polymers 0.000 claims description 18
- 230000001590 oxidative effect Effects 0.000 claims description 17
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 claims description 12
- 239000007800 oxidant agent Substances 0.000 claims description 12
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 10
- 238000004519 manufacturing process Methods 0.000 claims description 10
- 229910021578 Iron(III) chloride Inorganic materials 0.000 claims description 8
- 239000004205 dimethyl polysiloxane Substances 0.000 claims description 8
- 229940032296 ferric chloride Drugs 0.000 claims description 8
- RBTARNINKXHZNM-UHFFFAOYSA-K iron trichloride Chemical compound Cl[Fe](Cl)Cl RBTARNINKXHZNM-UHFFFAOYSA-K 0.000 claims description 8
- 239000000178 monomer Substances 0.000 claims description 8
- 229920000435 poly(dimethylsiloxane) Polymers 0.000 claims description 8
- -1 polydimethylsiloxane Polymers 0.000 claims description 8
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 8
- 238000004140 cleaning Methods 0.000 claims description 6
- 239000002904 solvent Substances 0.000 claims description 6
- 238000004528 spin coating Methods 0.000 claims description 6
- GKWLILHTTGWKLQ-UHFFFAOYSA-N 2,3-dihydrothieno[3,4-b][1,4]dioxine Chemical compound O1CCOC2=CSC=C21 GKWLILHTTGWKLQ-UHFFFAOYSA-N 0.000 claims description 4
- 239000008367 deionised water Substances 0.000 claims description 4
- 229910021641 deionized water Inorganic materials 0.000 claims description 4
- 238000001035 drying Methods 0.000 claims description 4
- 229920005839 ecoflex® Polymers 0.000 claims description 4
- 239000011521 glass Substances 0.000 claims description 4
- FYMCOOOLDFPFPN-UHFFFAOYSA-K iron(3+);4-methylbenzenesulfonate Chemical compound [Fe+3].CC1=CC=C(S([O-])(=O)=O)C=C1.CC1=CC=C(S([O-])(=O)=O)C=C1.CC1=CC=C(S([O-])(=O)=O)C=C1 FYMCOOOLDFPFPN-UHFFFAOYSA-K 0.000 claims description 4
- 238000002156 mixing Methods 0.000 claims description 4
- 239000003960 organic solvent Substances 0.000 claims description 4
- 238000003825 pressing Methods 0.000 claims description 4
- 238000002791 soaking Methods 0.000 claims description 4
- 206010011985 Decubitus ulcer Diseases 0.000 claims description 3
- 206010033799 Paralysis Diseases 0.000 claims description 3
- 208000004210 Pressure Ulcer Diseases 0.000 claims description 3
- 238000005452 bending Methods 0.000 claims description 3
- 238000013012 foaming technology Methods 0.000 claims description 3
- 238000012544 monitoring process Methods 0.000 claims description 3
- VAYOSLLFUXYJDT-RDTXWAMCSA-N Lysergic acid diethylamide Chemical compound C1=CC(C=2[C@H](N(C)C[C@@H](C=2)C(=O)N(CC)CC)C2)=C3C2=CNC3=C1 VAYOSLLFUXYJDT-RDTXWAMCSA-N 0.000 claims description 2
- 229920001609 Poly(3,4-ethylenedioxythiophene) Polymers 0.000 claims description 2
- 239000004642 Polyimide Substances 0.000 claims description 2
- 238000000151 deposition Methods 0.000 claims description 2
- 235000019441 ethanol Nutrition 0.000 claims description 2
- 229940044631 ferric chloride hexahydrate Drugs 0.000 claims description 2
- 238000011065 in-situ storage Methods 0.000 claims description 2
- NQXWGWZJXJUMQB-UHFFFAOYSA-K iron trichloride hexahydrate Chemical compound O.O.O.O.O.O.[Cl-].Cl[Fe+]Cl NQXWGWZJXJUMQB-UHFFFAOYSA-K 0.000 claims description 2
- 229920001721 polyimide Polymers 0.000 claims description 2
- 239000002861 polymer material Substances 0.000 claims description 2
- 229920002635 polyurethane Polymers 0.000 claims description 2
- 239000004814 polyurethane Substances 0.000 claims description 2
- 230000008569 process Effects 0.000 claims description 2
- BDERNNFJNOPAEC-UHFFFAOYSA-N propan-1-ol Chemical compound CCCO BDERNNFJNOPAEC-UHFFFAOYSA-N 0.000 claims description 2
- 238000005507 spraying Methods 0.000 claims description 2
- 238000010345 tape casting Methods 0.000 claims description 2
- 238000001548 drop coating Methods 0.000 claims 1
- 230000035945 sensitivity Effects 0.000 abstract description 7
- 239000002313 adhesive film Substances 0.000 abstract 1
- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical group [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 abstract 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 10
- 229910052802 copper Inorganic materials 0.000 description 10
- 239000010949 copper Substances 0.000 description 10
- 238000002360 preparation method Methods 0.000 description 8
- 230000004044 response Effects 0.000 description 7
- 239000011231 conductive filler Substances 0.000 description 5
- 239000002245 particle Substances 0.000 description 4
- 230000036544 posture Effects 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 2
- 239000003575 carbonaceous material Substances 0.000 description 2
- 238000013461 design Methods 0.000 description 2
- 238000001514 detection method Methods 0.000 description 2
- 230000004064 dysfunction Effects 0.000 description 2
- 230000006870 function Effects 0.000 description 2
- 238000011068 loading method Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 230000008447 perception Effects 0.000 description 2
- 229910052710 silicon Inorganic materials 0.000 description 2
- 239000010703 silicon Substances 0.000 description 2
- 238000005303 weighing Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000001276 controlling effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000036541 health Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 238000001000 micrograph Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 239000002086 nanomaterial Substances 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 238000004154 testing of material Methods 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L1/00—Measuring force or stress, in general
- G01L1/14—Measuring force or stress, in general by measuring variations in capacitance or inductance of electrical elements, e.g. by measuring variations of frequency of electrical oscillators
- G01L1/142—Measuring force or stress, in general by measuring variations in capacitance or inductance of electrical elements, e.g. by measuring variations of frequency of electrical oscillators using capacitors
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Measuring Fluid Pressure (AREA)
Abstract
The flexible capacitive pressure sensor based on porous structure and microstructure includes two parallel electrodes, one porous foam layer between the two parallel electrodes, one conductive polymer layer on the upper and lower surfaces of the porous foam layer, one micro structure elastomer layer attached to the porous foam layer, and one conductive adhesive tape or film for the upper and lower parallel electrodes to extend directly to serve as the lead wire connected to the external equipment. The method adopts a gas phase oxidation polymerization mode to deposit conductive polymer in foam materials; coating an elastomer material on a microstructured template to obtain a microstructure elastomer layer, lightly placing a polymerized porous structure foam layer on the microstructure elastomer layer, adhering the porous structure foam layer, and then heating and curing the porous structure foam layer, and repeating the steps to prepare a double-sided microstructure; the conductive adhesive tape or the conductive film is arranged on the upper side and the lower side to serve as upper and lower parallel electrodes, and directly extends to serve as a lead connected with external equipment, and the waterproof breathable adhesive tape is used for packaging. The invention has the characteristics of high sensitivity and good stability.
Description
Technical Field
The invention belongs to the technical field of pressure sensors, and particularly relates to a flexible capacitive pressure sensor based on a porous structure and a microstructure and a method thereof.
Background
Intelligent perception is an important role in realizing the functions of the wearable equipment, and the flexible pressure sensor is a key core for achieving the function, so that the intelligent perception system has very wide application fields including medical health, intelligent artificial limbs, motion detection, touch sensing and the like. The flexible pressure sensor can convert the pressure applied by the outside into an electrical signal, including capacitance, resistance, voltage and the like, and can be mainly divided into a capacitive pressure sensor, a resistive pressure sensor, a piezoelectric pressure sensor and a triboelectric sensor according to the different signals which can be converted. The microstructure design is a common means for regulating and controlling the sensing performance of the pressure sensor at present, and the microstructure can be constructed on the sensing layer to generate larger deformation under smaller pressure.
At present, the method for manufacturing the sensor by using the porous structure is mainly to dope conductive filler in a skeleton of the porous structure, and when stress is applied, a conductive path changes, so that the sensor is finally used as a resistance type pressure sensor, but the resistance type sensor is relatively unstable, is greatly influenced by stress deformation, has good stability and simple structure, and is more suitable for being worn for a long time. Meanwhile, the selection of the conductive filler is also a problem, and the conductive filler commonly used at present is a carbon-based and metal-based material, so that the preparation is complex, the price is high, and the conductive filler which is simple to prepare, good in conductivity and flexible needs to be searched. In addition, the current method for combining multiple microstructures can realize the preparation of a high-performance sensor, and becomes an important direction to be considered in the next step of sensor design.
Disclosure of Invention
In order to overcome the problems in the prior art, the invention aims to provide a flexible capacitive pressure sensor based on a porous structure and a microstructure and a method thereof.
In order to achieve the above purpose, the technical scheme adopted by the invention is as follows:
the flexible capacitive pressure sensor based on the porous structure and the microstructure comprises an upper parallel electrode 1 and a lower parallel electrode 1, a porous structure foam layer 3 is arranged between the two parallel electrodes 1, conductive polymers are chemically synthesized on the upper surface and the lower surface of the porous structure foam layer 3, a microstructure elastomer layer 2 is additionally arranged, and the upper parallel electrode 1 and the lower parallel electrode adopt conductive adhesive tapes or conductive films and respectively extend directly to serve as leads connected with external equipment.
The holes in the porous structure foam layer 3 are closed holes, the holes are not connected with each other, and the size is in the micron-sized range;
the thickness of the porous structure foam layer 3 ranges from 10 to 2000 micrometers; the thickness of the microstructured elastomeric layer 2 ranges from 1 to 100 micrometers;
the pore diameter of the porous structure foam layer 3 is about 30-50 microns; the conductive polymer is uniformly dispersed on the surface of the porous structure foam layer 3, embedded in the surface holes and not falling off; the microstructure elastomer layer 2 is of a pyramid array structure, the width, the height and the distance are all 5-20 micrometers, and the specific size of the microstructure elastomer layer 2 is set according to the correlation between the microstructure elastomer layer, the height and the distance and the sensitivity of the device. A preparation method of a flexible capacitive pressure sensor based on a porous structure and a microstructure comprises the following steps of;
s1, depositing a conductive polymer in a foam material in a gas-phase oxidation polymerization mode; obtaining a foam layer 3 with a porous structure;
s2, coating an elastomer material on a microstructured template to obtain a microstructure elastomer layer 2, lightly placing a polymerized porous structure foam layer 3 on the microstructure elastomer layer, adhering the porous structure foam layer 3 together, and then heating and curing the porous structure foam layer, and repeating the steps to prepare a double-sided microstructure;
s3, placing the conductive adhesive tapes or conductive films on the upper side and the lower side as upper and lower parallel electrodes 1, directly extending the conductive adhesive tapes or conductive films to serve as leads connected with external equipment, and packaging the conductive adhesive tapes or conductive films by using waterproof breathable adhesive tapes.
In the step S1, the gas phase oxidation polymerization method comprises the following steps:
s1-1, dissolving an oxidant in an organic solvent, and uniformly mixing to obtain an oxidant solution;
s1-2, soaking the foam material in an oxidant solution, taking out, and drying to remove redundant solvent;
s1-3, placing the dried foam material into a self-made oxidative polymerization device, namely a glass culture dish, dripping 3, 4-ethylenedioxythiophene monomer below, adhering the foam material above by using an adhesive tape, and heating the whole device on a hot table at the temperature of 60-80 ℃ for 1-3 hours;
s1-4, respectively cleaning the doped foam material for a plurality of times by using absolute ethyl alcohol and deionized water, and drying and storing to obtain the porous structure foam layer 3.
The porous structure foam layer 3 is prepared by doping conductive polymer monomers into the porous structure foam layer in a gas-phase in-situ oxidation polymerization mode, wherein the conductive polymer material is polyethylene dioxythiophene; the oxidant used in the polymerization process is one of ferric chloride, ferric chloride hexahydrate, ferric p-toluenesulfonate hexahydrate or ferric p-toluenesulfonate, and the organic solvent for dissolving the oxidant is one of methanol, ethanol and propanol.
The monomer content is between 50 and 300 mu L.
The thickness of the foam material is between 0.5 and 2mm, and the concentration of the oxidant solution is between 2.5 and 7.5 percent.
The porous structure foam layer 3 is an elastic layer prepared by adopting a foaming technology, the material of the porous structure foam layer 3 is an elastomer material, and the elastomer material is one of thermoplastic polyurethane, polydimethylsiloxane and Ecoflex. The dielectric layers with the microstructure elastomer layers 2 are made of elastomer materials, the elastomer materials comprise any one or a combination of at least two of polydimethylsiloxane, thermoplastic polyurethane, ecoflex, polyurethane and polyimide, and the microstructured templates comprise any one or a combination of at least two of micropyramids, micropillars, microcones, microdots and microgrooves.
The preparation method of the elastomer layer 2 with the microstructure is a template preparation method, which comprises one mode of spin coating, knife coating, spray coating or dripping coating of an elastomer material on a template.
The rotation speed of the spin coating process is 600 rpm-1200 rpm, and the spin coating time is 30-60 s.
The flexible capacitive pressure sensor based on the porous structure and the microstructure is suitable for motion monitoring, joint bending, pressing and the like, can be made into intelligent gloves to help patients with hand dysfunction to identify and grasp objects, and is made into intelligent cushions/mattresses for sitting/sleeping posture identification of paralyzed patients so as to avoid pressure sores.
The invention has the beneficial effects that:
(1) In the invention, the porous structure prepared by adopting the foaming technology is used as the inner layer of the dielectric layer, the holes prepared by the technology are not connected with each other, and when the conductive filler is doped, the sensor can be ensured to be a capacitive sensor instead of a resistive sensor, so that the sensor is more stable and has good reliability.
(2) The invention adopts a method of combining multiple structures to improve the performance of the sensor, combines the porous structure with the surface microstructure, combines the micrometer-scale structure with the nanometer-scale structure, effectively improves the sensitivity of the sensor, and simultaneously increases the sensing range.
(3) Compared with the traditional carbon-based material and metal nano material, the doped conductive polymer has lighter weight and flexibility, simple preparation and relatively low cost.
Drawings
Fig. 1 is a schematic diagram of a device structure of a flexible capacitive pressure sensor based on a porous structure and a microstructure according to an embodiment of the present invention.
Wherein 1 is a parallel electrode, 2 is a microstructure elastomer layer, and 3 is a porous structure foam layer.
FIG. 2 is a scanning electron microscope image of the cellular-structured thermoplastic polyurethane foam provided in example 1 of the present invention.
Fig. 3 is a top view of a polydimethylsiloxane film having a micropyramidal structure provided in example 1 of the present invention.
Fig. 4 is a cross-sectional view of a polydimethylsiloxane membrane having a micro-pyramidal structure provided in example 1 of the present invention.
Fig. 5 is a cross-sectional view of an integral dielectric layer provided in embodiment 1 of the present invention.
Fig. 6 is a response to pressure of a flexible capacitive pressure sensor based on a porous structure and a microstructure according to embodiment 1 of the present invention.
Fig. 7 shows the response results of a flexible capacitive pressure sensor based on a porous structure and a microstructure under stress loading at different frequencies according to embodiment 1 of the present invention.
Fig. 8 shows the response results of a flexible capacitive pressure sensor based on porous structures and microstructures under stress loading of different magnitudes according to embodiment 1 of the present invention.
Detailed Description
The invention is described in further detail below with reference to the drawings and examples.
Example 1
In the experimental example, the flexible capacitive pressure sensor device structure based on the porous structure and the microstructure shown in fig. 1 is adopted, the upper electrode layer and the lower electrode layer adopt copper strips, the dielectric layer adopts thermoplastic polyurethane foam, the elastic layers above and below the foam layer adopt thermoplastic polyurethane films in a micro pyramid shape, and the upper copper strip electrode layer and the lower copper strip electrode layer respectively directly extend the copper strips to be used as leads connected with external equipment.
The preparation of the flexible capacitive pressure sensor based on the porous structure and the microstructure is completed through the following specific steps:
s1, weighing 0.2g of ferric chloride particles, dissolving the ferric chloride particles in 4ml of methanol solvent, and uniformly mixing;
s2, placing the thermoplastic polyurethane foam into the prepared ferric chloride solution, soaking for 15 minutes, taking out, and placing the thermoplastic polyurethane foam on a hot table at 70 ℃ for heating for 15 minutes to remove redundant solvents;
s3, placing the dried foam into a self-made oxidative polymerization device, namely a glass culture dish, taking 200 mu L of 3, 4-ethylenedioxythiophene monomer to drop below, adhering a foam material to above by using an adhesive tape, and heating the whole device at a heat table at the temperature of 75 ℃ for 2 hours;
s4, taking down the foam, ultrasonically cleaning the foam with absolute ethyl alcohol for 3 times, and ultrasonically cleaning the foam with deionized water for 3 times;
s5, placing the mixture in a heat table at 80 ℃ to heat and dry the water, and storing the dried water;
s6, coating a polydimethylsiloxane solution prepared according to a mass ratio of 10:1 on a silicon wafer template of the micro pyramid;
s7, lightly placing the polymerized thermoplastic polyurethane foam on the heat table at 80 ℃ for curing after adhering the thermoplastic polyurethane foam together;
s8, replacing the other surface, continuously repeating the operation S3, and preparing an elastic layer with a micro pyramid structure on both surfaces;
s9, placing the copper strips on the upper side and the lower side to serve as electrodes, and directly extending out to serve as leads connected with external equipment;
s10, sequentially packaging by using adhesive tapes according to the structural sequence of the device shown in FIG. 1.
In the experimental example, the prepared dielectric layer is observed by a scanning electron microscope as shown in figures 3,4 and 5, the surface micro pyramid structure can be completely manufactured, the scanning electron microscope of the used thermoplastic polyurethane foam is shown in figure 2, the micro-scale holes can be formed, the holes are not connected with each other, the prepared flexible capacitive pressure sensor is used for testing the force sensitivity, the sensor is connected with a portable testing device, a universal material testing machine is used for continuously applying pressure to the sensor and testing the pressure response performance of the sensor, and the maximum sensitivity of the prepared flexible capacitive pressure sensor based on the porous structure and the micro structure reaches 55.4233kPa -1 Very high sensitivity can be achieved, with a sensing range between 0 and 30 kPa. And the pressure response conditions measured when the stress with different frequencies and different magnitudes is circularly loaded on the sensor are shown in fig. 7 and 8, the pressure with different frequencies has almost no influence on the electrical response, the normal operation can be stabilized, the electrical response is stable when the stress with different magnitudes is applied, and the stress is increasedIncreasing. The flexible capacitive pressure sensor based on the porous structure and the microstructure has the characteristics of high sensitivity, high stability and wide detection range, is suitable for various pressure sensing requirements such as motion monitoring, joint bending, pressing and the like, can be made into intelligent gloves to help patients with hand dysfunction to identify and grasp objects, and can be made into intelligent cushions/mattresses for identifying sitting postures/sleeping postures of paralyzed patients so as to avoid pressure sores.
Example 2
In the experimental example, the flexible capacitive pressure sensor device structure based on the porous structure and the microstructure shown in fig. 1 is adopted, the upper electrode layer and the lower electrode layer adopt copper strips, the dielectric layer adopts thermoplastic polyurethane foam, the elastic layers above and below the foam layer adopt thermoplastic polyurethane films in a micro pyramid shape, and the upper copper strip electrode layer and the lower copper strip electrode layer respectively directly extend the copper strips to be used as leads connected with external equipment.
The preparation of the flexible capacitive pressure sensor based on the porous structure and the microstructure is completed through the following specific steps:
s1, weighing 0.4g of ferric chloride particles, dissolving the ferric chloride particles in 4ml of methanol solvent, and uniformly mixing;
s2, placing the thermoplastic polyurethane foam into the prepared ferric chloride solution, soaking for 15 minutes, taking out, and placing the thermoplastic polyurethane foam on a hot table at 70 ℃ for heating for 15 minutes to remove redundant solvents;
s3, placing the dried foam into a self-made oxidative polymerization device, namely a glass culture dish, taking 100 mu L of 3, 4-ethylenedioxythiophene monomer to drop below, adhering a foam material to above by using an adhesive tape, and heating the whole device at a heat table at the temperature of 75 ℃ for 2 hours;
s4, taking down the foam, ultrasonically cleaning the foam with absolute ethyl alcohol for 3 times, and ultrasonically cleaning the foam with deionized water for 3 times;
s5, placing the mixture in a heat table at 80 ℃ to heat and dry the water, and storing the dried water;
s6, coating a polydimethylsiloxane solution prepared according to a mass ratio of 10:1 on a silicon wafer template of the micro pyramid;
s7, lightly placing the polymerized thermoplastic polyurethane foam on the heat table at 80 ℃ for curing after adhering the thermoplastic polyurethane foam together;
s8, replacing the other surface, continuously repeating the operation S3, and preparing an elastic layer with a micro pyramid structure on both surfaces;
s9, placing the copper strips on the upper side and the lower side to serve as electrodes, and directly extending out to serve as leads connected with external equipment;
s10, sequentially packaging by using adhesive tapes according to the structural sequence of the device shown in FIG. 1.
The mechatronic characteristics were also measured, and it was found by comparison that the sensor prepared in example 1 had more excellent performance.
Finally, the methods of the present application are only preferred embodiments and are not intended to limit the scope of the invention. Any modification, equivalent replacement, improvement, etc. made within the protection and principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. The flexible capacitive pressure sensor based on the porous structure and the microstructure is characterized by comprising an upper parallel electrode (1) and a lower parallel electrode (1), wherein a porous structure foam layer (3) is arranged between the two parallel electrodes (1), conductive polymers are chemically synthesized on the upper surface and the lower surface of the porous structure foam layer (3), an elastomer layer (2) with the microstructure is additionally arranged, and the upper parallel electrode (1) and the lower parallel electrode adopt conductive adhesive tapes or conductive films and respectively extend directly to serve as leads connected with external equipment.
2. A flexible capacitive pressure sensor based on porous structures and microstructures according to claim 1, characterized in that the holes in the porous structure foam layer (3) are closed holes, the holes are not connected with each other, and the size is in the micrometer range;
the thickness of the porous structure foam layer (3) ranges from 10 to 2000 micrometers; the thickness of the microstructure elastomer layer (2) ranges from 1 to 100 micrometers;
the diameter of the holes of the porous structure foam layer (3) is about 30-50 micrometers, the conductive polymer is uniformly dispersed on the surface of the porous structure foam layer (3) and embedded into the surface holes, and the conductive polymer cannot fall off, and the microstructure elastomer layer (2) is of a pyramid array structure, and the width, the height and the spacing are all 5-20 micrometers.
3. A method for manufacturing a flexible capacitive pressure sensor based on a porous structure and a microstructure according to claim 1 or 2, characterized in that it comprises the following steps;
s1, depositing a conductive polymer in a foam material in a gas-phase oxidation polymerization mode; obtaining a foam layer (3) with a porous structure;
s2, coating an elastomer material on a microstructured template to obtain a microstructure elastomer layer (2), lightly placing a polymerized porous structure foam layer (3) on the microstructure elastomer layer, adhering the porous structure foam layer and the porous structure foam layer, heating and curing the porous structure foam layer, and repeating the steps to prepare a double-sided microstructure;
s3, placing the conductive adhesive tapes or the conductive films on the upper side and the lower side as upper and lower parallel electrodes (1), directly extending the conductive adhesive tapes or the conductive films to serve as leads connected with external equipment, and packaging the conductive adhesive tapes or the conductive films by using waterproof breathable adhesive tapes.
4. A method for manufacturing a flexible capacitive pressure sensor based on a porous structure and a microstructure according to claim 3, wherein in S1, the gas phase oxidative polymerization method comprises the steps of:
s1-1, dissolving an oxidant in an organic solvent, and uniformly mixing to obtain an oxidant solution;
s1-2, soaking the foam material in an oxidant solution, taking out, and drying to remove redundant solvent;
s1-3, placing the dried foam material into a self-made oxidative polymerization device, namely a glass culture dish, dripping 3, 4-ethylenedioxythiophene monomer below, adhering the foam material above by using an adhesive tape, and heating the whole device on a hot table at the temperature of 60-80 ℃ for 1-3 hours;
s1-4, respectively cleaning the doped foam material for a plurality of times by using absolute ethyl alcohol and deionized water, and drying and storing to obtain the porous structure foam layer (3).
5. The method for manufacturing a flexible capacitive pressure sensor based on a porous structure and a microstructure according to claim 4, wherein the porous structure foam layer (3) is formed by doping conductive polymer monomers therein by means of gas phase in situ oxidative polymerization, and the conductive polymer material is polyethylene dioxythiophene; the oxidant used in the polymerization process is one of ferric chloride, ferric chloride hexahydrate, ferric p-toluenesulfonate hexahydrate or ferric p-toluenesulfonate, and the organic solvent for dissolving the oxidant is one of methanol, ethanol and propanol.
6. The method for manufacturing a flexible capacitive pressure sensor based on a porous structure and a microstructure according to claim 5, wherein the monomer content is between 50 and 300 μl.
7. The method for manufacturing a flexible capacitive pressure sensor based on a porous structure and a microstructure according to claim 4, wherein the thickness of the foam material is between 0.5 and 2mm, and the concentration of the oxidizer solution is between 2.5% and 7.5%;
the porous structure foam layer (3) is an elastic layer prepared by adopting a foaming technology, the material of the porous structure foam layer (3) is an elastomer material, and the elastomer material is one of thermoplastic polyurethane, polydimethylsiloxane and Ecoflex.
8. The method for manufacturing a flexible capacitive pressure sensor based on a porous structure and a microstructure according to claim 3, wherein the dielectric layers with the microstructure elastomer layers (2) are made of an elastomer material, and the elastomer material comprises any one or a combination of at least two of polydimethylsiloxane, thermoplastic polyurethane, ecoflex, polyurethane and polyimide, and the microstructured template comprises any one or a combination of at least two of micropyramids, micropillars, microcones, microdots and microgrooves.
9. A method of manufacturing a flexible capacitive pressure sensor based on a porous structure and microstructure according to claim 3, characterized in that the method of manufacturing the elastomer layer (2) with microstructure is a template manufacturing method comprising one of spin coating, knife coating, spray coating or drop coating of an elastomer material on a template;
the rotation speed of the spin coating process is 600 rpm-1200 rpm, and the spin coating time is 30-60 s.
10. The flexible capacitive pressure sensor of any one of claims 1-9, wherein the flexible capacitive pressure sensor is suitable for motion monitoring, joint bending, pressing, and can be made into intelligent gloves to help hand dysfunctional patients identify gripping objects, and intelligent cushions/mattresses for paralyzed patients sitting/sleeping posture identification to avoid pressure sores.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310525933.1A CN116380301A (en) | 2023-05-11 | 2023-05-11 | Flexible capacitive pressure sensor and method based on porous structure and microstructure |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310525933.1A CN116380301A (en) | 2023-05-11 | 2023-05-11 | Flexible capacitive pressure sensor and method based on porous structure and microstructure |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116380301A true CN116380301A (en) | 2023-07-04 |
Family
ID=86967654
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310525933.1A Pending CN116380301A (en) | 2023-05-11 | 2023-05-11 | Flexible capacitive pressure sensor and method based on porous structure and microstructure |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116380301A (en) |
-
2023
- 2023-05-11 CN CN202310525933.1A patent/CN116380301A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Li et al. | Recent progress in flexible and stretchable piezoresistive sensors and their applications | |
| CN109576905B (en) | MXene-based flexible polyurethane fiber membrane strain sensor | |
| CN111505065B (en) | Interdigital counter electrode type flexible touch sensor based on super-capacitor sensing principle and preparation method thereof | |
| CN106908176B (en) | Multi-phase dielectric layer capacitive pressure sensor with micro-structure and manufacturing method thereof | |
| CN111759315B (en) | Preparation method of self-powered electronic skin system based on laser reduction graphene/MXene composite material | |
| Ma et al. | Recent progress in flexible capacitive sensors: Structures and properties | |
| CN110220619A (en) | Pliable pressure sensor based on hollow ball structure and preparation method thereof | |
| CN102770742B (en) | Flexible pressure sensor and flexible pressure sensing array | |
| Wan et al. | Sugar-templated conductive polyurethane-polypyrrole sponges for wide-range force sensing | |
| Cheng et al. | Low‐cost, highly sensitive, and flexible piezoresistive pressure sensor characterized by low‐temperature interfacial polymerization of polypyrrole on latex sponge | |
| CN112326074B (en) | Touch sensor, preparation method and intelligent device comprising touch sensor | |
| Huang et al. | Improvement of piezoresistive sensing behavior of graphene sponge by polyaniline nanoarrays | |
| WO2015179320A1 (en) | Flexible sensor apparatus | |
| CN113340484A (en) | Wide-range flexible resistance type pressure sensor and preparation method thereof | |
| CN109724723B (en) | Textile material-based wearable pressure sensor and preparation method thereof | |
| WO2021253278A1 (en) | Touch sensor, manufacturing method, and intelligent device comprising touch sensor | |
| CN110699949B (en) | Flexible self-adhesive cloth with pressure/friction force sensing function, flexible mechanical sensor and preparation method of flexible mechanical sensor | |
| CN111024272A (en) | Preparation method of capacitive flexible sensor | |
| KR101691910B1 (en) | Strain Sensor and Manufacturing Method of The Same | |
| Zeng et al. | A low-cost flexible capacitive pressure sensor for health detection | |
| CN203965077U (en) | A kind of fexible film touch sensor | |
| Wang et al. | A flexible pressure sensor based on composite piezoresistive layer | |
| Liu et al. | Superstretchable and Linear-Response Strain Sensors With Carbon Nanotubes Ultrasonically Assembled on Silicone Rubber Film | |
| Guo et al. | AP (VDF-TrFE) nanofiber composites based multilayer structured dual-functional flexible sensor for advanced pressure-humidity sensing | |
| Chen et al. | Microstructured flexible pressure sensor based on nanofibrous films for human motions and physiological detection |
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 |