CN115468687A - Flexible pressure sensor and preparation method thereof - Google Patents
Flexible pressure sensor and preparation method thereof Download PDFInfo
- Publication number
- CN115468687A CN115468687A CN202210914993.8A CN202210914993A CN115468687A CN 115468687 A CN115468687 A CN 115468687A CN 202210914993 A CN202210914993 A CN 202210914993A CN 115468687 A CN115468687 A CN 115468687A
- Authority
- CN
- China
- Prior art keywords
- self
- layer
- repairing
- hydrogel layer
- flexible
- 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
- 238000002360 preparation method Methods 0.000 title claims abstract description 24
- 239000000017 hydrogel Substances 0.000 claims abstract description 212
- 239000003792 electrolyte Substances 0.000 claims abstract description 130
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 63
- 239000000463 material Substances 0.000 claims description 47
- 239000000499 gel Substances 0.000 claims description 24
- 238000000034 method Methods 0.000 claims description 24
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 21
- 239000004372 Polyvinyl alcohol Substances 0.000 claims description 20
- 229920002451 polyvinyl alcohol Polymers 0.000 claims description 20
- 239000002131 composite material Substances 0.000 claims description 16
- 239000002243 precursor Substances 0.000 claims description 15
- 239000007772 electrode material Substances 0.000 claims description 13
- 239000006185 dispersion Substances 0.000 claims description 12
- 239000002001 electrolyte material Substances 0.000 claims description 12
- 239000002002 slurry Substances 0.000 claims description 12
- 244000137852 Petrea volubilis Species 0.000 claims description 10
- 239000002041 carbon nanotube Substances 0.000 claims description 10
- 229910021393 carbon nanotube Inorganic materials 0.000 claims description 10
- 229910021389 graphene Inorganic materials 0.000 claims description 10
- 238000004519 manufacturing process Methods 0.000 claims description 10
- 238000000967 suction filtration Methods 0.000 claims description 9
- PEDCQBHIVMGVHV-UHFFFAOYSA-N Glycerine Chemical compound OCC(O)CO PEDCQBHIVMGVHV-UHFFFAOYSA-N 0.000 claims description 8
- 239000011358 absorbing material Substances 0.000 claims description 8
- 239000007788 liquid Substances 0.000 claims description 8
- 239000000758 substrate Substances 0.000 claims description 8
- 239000000126 substance Substances 0.000 claims description 7
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 claims description 5
- 239000002250 absorbent Substances 0.000 claims description 5
- 229910052582 BN Inorganic materials 0.000 claims description 4
- PZNSFCLAULLKQX-UHFFFAOYSA-N Boron nitride Chemical compound N#B PZNSFCLAULLKQX-UHFFFAOYSA-N 0.000 claims description 4
- -1 MXene Substances 0.000 claims description 4
- TWRXJAOTZQYOKJ-UHFFFAOYSA-L Magnesium chloride Chemical compound [Mg+2].[Cl-].[Cl-] TWRXJAOTZQYOKJ-UHFFFAOYSA-L 0.000 claims description 4
- 239000013310 covalent-organic framework Substances 0.000 claims description 4
- KWGKDLIKAYFUFQ-UHFFFAOYSA-M lithium chloride Chemical compound [Li+].[Cl-] KWGKDLIKAYFUFQ-UHFFFAOYSA-M 0.000 claims description 4
- 229910052751 metal Inorganic materials 0.000 claims description 4
- 239000002184 metal Substances 0.000 claims description 4
- 239000002082 metal nanoparticle Substances 0.000 claims description 4
- 239000012621 metal-organic framework Substances 0.000 claims description 4
- CWQXQMHSOZUFJS-UHFFFAOYSA-N molybdenum disulfide Chemical compound S=[Mo]=S CWQXQMHSOZUFJS-UHFFFAOYSA-N 0.000 claims description 4
- 229910052982 molybdenum disulfide Inorganic materials 0.000 claims description 4
- 239000002070 nanowire Substances 0.000 claims description 4
- ITRNXVSDJBHYNJ-UHFFFAOYSA-N tungsten disulfide Chemical compound S=[W]=S ITRNXVSDJBHYNJ-UHFFFAOYSA-N 0.000 claims description 4
- IXPNQXFRVYWDDI-UHFFFAOYSA-N 1-methyl-2,4-dioxo-1,3-diazinane-5-carboximidamide Chemical compound CN1CC(C(N)=N)C(=O)NC1=O IXPNQXFRVYWDDI-UHFFFAOYSA-N 0.000 claims description 3
- 229920001817 Agar Polymers 0.000 claims description 3
- 229920001661 Chitosan Polymers 0.000 claims description 3
- 108010010803 Gelatin Proteins 0.000 claims description 3
- 239000008272 agar Substances 0.000 claims description 3
- 238000000151 deposition Methods 0.000 claims description 3
- 238000001035 drying Methods 0.000 claims description 3
- 229920000159 gelatin Polymers 0.000 claims description 3
- 239000008273 gelatin Substances 0.000 claims description 3
- 235000019322 gelatine Nutrition 0.000 claims description 3
- 235000011852 gelatine desserts Nutrition 0.000 claims description 3
- 235000011187 glycerol Nutrition 0.000 claims description 3
- 229920002401 polyacrylamide Polymers 0.000 claims description 3
- 239000000661 sodium alginate Substances 0.000 claims description 3
- 235000010413 sodium alginate Nutrition 0.000 claims description 3
- 229940005550 sodium alginate Drugs 0.000 claims description 3
- 239000002904 solvent Substances 0.000 claims description 3
- UXVMQQNJUSDDNG-UHFFFAOYSA-L Calcium chloride Chemical compound [Cl-].[Cl-].[Ca+2] UXVMQQNJUSDDNG-UHFFFAOYSA-L 0.000 claims description 2
- 239000001110 calcium chloride Substances 0.000 claims description 2
- 229910001628 calcium chloride Inorganic materials 0.000 claims description 2
- 229910001629 magnesium chloride Inorganic materials 0.000 claims description 2
- WGCNASOHLSPBMP-UHFFFAOYSA-N hydroxyacetaldehyde Natural products OCC=O WGCNASOHLSPBMP-UHFFFAOYSA-N 0.000 claims 1
- 230000035945 sensitivity Effects 0.000 abstract description 22
- 230000008859 change Effects 0.000 abstract description 6
- 239000010410 layer Substances 0.000 description 329
- 230000005540 biological transmission Effects 0.000 description 21
- 150000002500 ions Chemical class 0.000 description 20
- 230000000694 effects Effects 0.000 description 12
- 238000006243 chemical reaction Methods 0.000 description 10
- 230000007246 mechanism Effects 0.000 description 10
- 230000000052 comparative effect Effects 0.000 description 8
- 239000008367 deionised water Substances 0.000 description 8
- 229910021641 deionized water Inorganic materials 0.000 description 8
- 238000012360 testing method Methods 0.000 description 8
- 230000006870 function Effects 0.000 description 7
- 230000008569 process Effects 0.000 description 6
- 239000000243 solution Substances 0.000 description 6
- 230000003068 static effect Effects 0.000 description 6
- 238000010521 absorption reaction Methods 0.000 description 4
- 230000009286 beneficial effect Effects 0.000 description 4
- 238000001514 detection method Methods 0.000 description 4
- 238000005538 encapsulation Methods 0.000 description 4
- 230000002349 favourable effect Effects 0.000 description 4
- 230000002745 absorbent Effects 0.000 description 3
- 238000005266 casting Methods 0.000 description 3
- 125000004122 cyclic group Chemical group 0.000 description 3
- 238000011161 development Methods 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 238000012544 monitoring process Methods 0.000 description 3
- 230000001105 regulatory effect Effects 0.000 description 3
- 230000008439 repair process Effects 0.000 description 3
- 238000003756 stirring Methods 0.000 description 3
- 238000009210 therapy by ultrasound Methods 0.000 description 3
- 230000009471 action Effects 0.000 description 2
- 238000013329 compounding Methods 0.000 description 2
- 230000001276 controlling effect Effects 0.000 description 2
- 238000005520 cutting process Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000003517 fume Substances 0.000 description 2
- 230000036541 health Effects 0.000 description 2
- 230000036571 hydration Effects 0.000 description 2
- 238000006703 hydration reaction Methods 0.000 description 2
- 238000010030 laminating Methods 0.000 description 2
- 239000002346 layers by function Substances 0.000 description 2
- 230000007774 longterm Effects 0.000 description 2
- 239000011259 mixed solution Substances 0.000 description 2
- VLKZOEOYAKHREP-UHFFFAOYSA-N n-Hexane Chemical compound CCCCCC VLKZOEOYAKHREP-UHFFFAOYSA-N 0.000 description 2
- 229920000642 polymer Polymers 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 229920006395 saturated elastomer Polymers 0.000 description 2
- 239000007784 solid electrolyte Substances 0.000 description 2
- 238000005507 spraying Methods 0.000 description 2
- 230000002195 synergetic effect Effects 0.000 description 2
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 239000010793 electronic waste Substances 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- 230000014509 gene expression Effects 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000007641 inkjet printing Methods 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 230000037427 ion transport Effects 0.000 description 1
- 230000001788 irregular Effects 0.000 description 1
- 238000001755 magnetron sputter deposition Methods 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 239000004005 microsphere Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000004806 packaging method and process Methods 0.000 description 1
- 238000011056 performance test Methods 0.000 description 1
- 238000007639 printing Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000001338 self-assembly Methods 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 125000006850 spacer group Chemical group 0.000 description 1
- 230000002269 spontaneous effect Effects 0.000 description 1
- 230000000638 stimulation Effects 0.000 description 1
- 238000010345 tape casting 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
- G01L1/20—Measuring force or stress, in general by measuring variations in ohmic resistance of solid materials or of electrically-conductive fluids; by making use of electrokinetic cells, i.e. liquid-containing cells wherein an electrical potential is produced or varied upon the application of stress
- G01L1/22—Measuring force or stress, in general by measuring variations in ohmic resistance of solid materials or of electrically-conductive fluids; by making use of electrokinetic cells, i.e. liquid-containing cells wherein an electrical potential is produced or varied upon the application of stress using resistance strain gauges
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L19/00—Details of, or accessories for, apparatus for measuring steady or quasi-steady pressure of a fluent medium insofar as such details or accessories are not special to particular types of pressure gauges
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L9/00—Measuring steady of quasi-steady pressure of fluid or fluent solid material by electric or magnetic pressure-sensitive elements; Transmitting or indicating the displacement of mechanical pressure-sensitive elements, used to measure the steady or quasi-steady pressure of a fluid or fluent solid material, by electric or magnetic means
- G01L9/08—Measuring steady of quasi-steady pressure of fluid or fluent solid material by electric or magnetic pressure-sensitive elements; Transmitting or indicating the displacement of mechanical pressure-sensitive elements, used to measure the steady or quasi-steady pressure of a fluid or fluent solid material, by electric or magnetic means by making use of piezoelectric devices, i.e. electric circuits therefor
Abstract
The application belongs to the technical field of sensors, and particularly relates to a flexible pressure sensor and a preparation method thereof. The preparation method of the flexible pressure sensor comprises the following steps: preparing a first self-repairing hydrogel layer and a second self-repairing hydrogel layer containing moisture; respectively attaching the first self-repairing hydrogel layer and the second self-repairing hydrogel layer to the two side surfaces of the electrolyte layer to obtain a pressure sensing layer; and preparing a first flexible electrode on the surface of the first self-repairing hydrogel layer in the pressure sensing layer, and preparing a second flexible electrode on the surface of the second self-repairing hydrogel layer to obtain the flexible pressure sensor. When the flexible pressure sensor is subjected to external pressure, sensing can be realized through the intrinsic impedance change of the electrolyte layer and the self-repairing hydrogel layer when the electrolyte layer and the self-repairing hydrogel layer are pressed; and the contact resistance of the interface can be changed by changing the contact area of the self-repairing hydrogel layer and the electrode layer, so that pressure sensing is realized, the pressure sensing sensitivity is high, and the pressure sensing range is wide.
Description
Technical Field
The application belongs to the technical field of sensors, and particularly relates to a flexible pressure sensor and a preparation method thereof.
Background
The flexible pressure sensor is used as an important component in a wearable intelligent product, and has potential development requirements in the fields of health monitoring, electronic skin, artificial limbs, man-machine interaction and the like. With the rapid development of wearable equipment, in order to meet the application requirements of real-time and long-term signal monitoring, higher requirements are put forward on the durability and portability of the flexible pressure sensor. In the actual use process, the device is easy to have mechanical damages such as creases, scratches and even cracks due to bending, friction and collision, the damages can not only reduce the operation stability of the sensor, but also cause the electrical performance of the device to fail, thereby shortening the service life of the flexible device, therefore, the use of the material with self-repairing performance has important significance for enhancing the durability of the flexible pressure sensor, prolonging the service life of the device and reducing electronic waste. At present, in traditional flexible pressure sensors such as piezoresistive type, capacitive type, piezoelectric type and triboelectric type, self-repairing materials are applied to piezoresistive type and capacitive type flexible pressure sensors more. But most of them require an additional external power supply due to the limitation of their sensing mechanism; while piezoelectric and triboelectric sensors can achieve passive sensing by converting mechanical energy into electrical energy. However, they have difficulty in measuring static force, and stable static force detection is crucial to the application development of flexible pressure sensors in the fields of electronic skin and health monitoring.
At present, researchers have proposed a potential conversion mechanism based on a galvanic cell by using hydrated Graphene Oxide (GO) as an electrolyte and a sensing layer, and the self-powered pressure sensing of dynamic and static forces is realized by converting pressure stimulation into a potential difference between two electrodes. However, since hydrated GO is susceptible to water loss from the external environment, which in turn affects the sensing performance of the device, the device needs to be packaged to isolate the external environment. This not only makes the preparation technology more complicated, increases the cost, and once the device takes place mechanical damage in the use, will cause its sensing performance to worsen even lose efficacy, and can't change or repair electrode and electrolyte material, cause the long-term durability and the reliability of device to reduce, life shortens. At present, a flexible pressure sensor which is convenient to wear, simple in preparation process, long in service life, capable of detecting static pressure and has spontaneous electric performance is still needed to be researched.
Disclosure of Invention
The application aims to provide a flexible pressure sensor and a preparation method thereof, and aims to solve the problem that the service life, the static pressure detection performance and the self-generating performance of the conventional flexible sensor are still to be further improved to a certain extent.
In order to achieve the purpose of the application, the technical scheme adopted by the application is as follows:
in a first aspect, the present application provides a method for manufacturing a flexible pressure sensor, comprising the steps of:
preparing a first self-repairing hydrogel layer and a second self-repairing hydrogel layer, wherein the first self-repairing hydrogel layer and the second self-repairing hydrogel layer respectively contain moisture;
preparing an electrolyte layer, and respectively attaching the first self-repairing hydrogel layer and the second self-repairing hydrogel layer to the two side surfaces of the electrolyte layer to obtain a pressure sensing layer;
and preparing a first flexible electrode on the surface of the first self-repairing hydrogel layer in the pressure sensing layer, and preparing a second flexible electrode on the surface of the second self-repairing hydrogel layer to obtain the flexible pressure sensor.
In a second aspect, the application provides a flexible pressure sensor, which comprises a first flexible electrode, a composite pressure sensing layer and a second flexible electrode, wherein the first flexible electrode, the composite pressure sensing layer and the second flexible electrode are sequentially attached; the composite pressure sensing layer at least comprises a pressure sensing layer formed by sequentially attaching a first self-repairing hydrogel layer, an electrolyte layer and a second self-repairing hydrogel layer; wherein the first self-repairing hydrogel layer and the second self-repairing hydrogel layer each contain moisture.
According to the preparation method of the flexible pressure sensor, two self-repairing hydrogel layers containing moisture are prepared, the two self-repairing hydrogel layers are respectively attached to the surfaces of the two sides of the electrolyte layer to form the pressure sensing layer with a sandwich structure, and meanwhile the pressure sensing layer is also a solid electrolyte. And then preparing a flexible electrode on the surface of the self-repairing hydrogel layer of the pressure sensing layer to obtain the flexible pressure sensor. The flexible pressure sensor is designed based on a potential conversion mechanism and has self-repairing and self-powered characteristics. Particularly, on the one hand, the self-repairing hydrogel layers arranged on the two sides can realize the self-repairing performance of the electrolyte layer and the electrode layer through the self-repairing function of hydrogel, so that the flexible pressure sensor has the self-repairing characteristic, can achieve the self-repairing effect when being damaged by the outside, and is long in service life. On the other hand, the pressure sensing layer comprises electrolyte layer and the self-repairing hydrogel layer of the water content of setting in its both sides constitutes sandwich structure, the self-repairing hydrogel layer of both sides has certain water content, not only can provide appropriate amount of hydrone for middle electrolyte layer, promote electrolyte layer's ion transmission ability, and can play the effect of encapsulation to middle electrolyte layer, play the water retention effect to electrolyte layer simultaneously, maintain the content of hydrone in electrolyte layer, thereby ensure electrolyte layer's ion transmission ability, need not to carry out extra hydration treatment to electrolyte layer, and need not encapsulation treatment once more, the technology has been simplified. The pressure sensing layer of the sandwich structure is formed by the first self-repairing hydrogel layer, the electrolyte layer and the second self-repairing hydrogel layer, so that when the sensor is stressed, sensing can be realized through the change of intrinsic impedance of the electrolyte layer and the self-repairing hydrogel layer when the sensor is stressed; and the contact resistance of the interface can be changed by changing the contact area of the self-repairing hydrogel layer and the electrode layer, so that pressure sensing is realized. The pressure sensing sensitivity of the flexible pressure sensor can be improved through the combination of the two structures, and the pressure sensing range is expanded.
The flexible pressure sensor that this application second aspect provided, this flexible pressure sensor is based on the design of potential conversion mechanism, sets up the selfreparing hydrogel layer in the pressure sensing layer in electrolyte layer both sides, can realize the selfreparing performance of electrolyte layer and electrode layer for flexible pressure sensor has the selfreparing characteristic, can reach the effect of selfreparing when receiving external damage, long service life. Meanwhile, the self-repairing hydrogel layers on the two sides have certain water content, water molecules required for ion transmission can be provided for the middle electrolyte layer, a water retention effect can be achieved on the electrolyte layer, and the ion transmission capability of the electrolyte layer is ensured. The flexible pressure sensor has self-repairing and self-power-supplying characteristics through the synergistic effect of the functional layers. When external pressure is applied, sensing can be realized through the change of intrinsic impedance of the electrolyte layer and the self-repairing hydrogel layer when the electrolyte layer and the self-repairing hydrogel layer are pressed; and the contact resistance of the interface can be changed by changing the contact area of the self-repairing hydrogel layer and the electrode layer, so that pressure sensing is realized. The pressure sensing sensitivity is high, and the pressure sensing range is wide.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.
Fig. 1 is a schematic flow chart of a method for manufacturing a flexible pressure sensor provided in an embodiment of the present application;
FIG. 2 is a schematic diagram of a structure of a flexible pressure sensor provided in an embodiment of the present application;
FIG. 3 is a schematic diagram of another structure of a flexible pressure sensor provided in an embodiment of the present application;
FIG. 4 is a graph showing output voltage signals of the flexible pressure sensor provided in example 1 of the present application at constant cyclic pressures of 2kPa, 5kPa, and 10kPa, respectively;
FIG. 5 is a graph of an output voltage signal of the flexible pressure sensor provided in embodiment 1 of the present application under a constant cyclic pressure of 10kPa after self-repairing of fracture.
Detailed Description
In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly apparent, the present application is further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.
In this application, the term "and/or" describes an association relationship of associated objects, meaning that there may be three relationships, e.g., a and/or B, which may mean: a alone, A and B together, and B alone. Wherein A and B can be singular or plural. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship.
In the present application, "at least one" means one or more, "a plurality" means two or more. "at least one of the following" or similar expressions refer to any combination of these items, including any combination of the singular or plural items. For example, "at least one (one) of a, b, or c," or "at least one (one) of a, b, and c," may each represent: a, b, c, a-b (i.e., a and b), a-c, b-c, or a-b-c, wherein a, b, and c may be single or plural, respectively.
It should be understood that, in various embodiments of the present application, the sequence numbers of the above-mentioned processes do not mean the execution sequence, some or all of the steps may be executed in parallel or executed sequentially, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.
The terminology used in the embodiments of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in the examples of this application and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.
The weight of the related components mentioned in the embodiments of the present specification may not only refer to the specific content of each component, but also represent the proportional relationship of the weight of each component, and therefore, the proportional enlargement or reduction of the content of the related components according to the embodiments of the present specification is within the scope disclosed in the embodiments of the present specification. Specifically, the mass in the examples of the present application may be in units of mass known in the chemical field such as μ g, mg, g, kg, etc.
The terms "first" and "second" are used for descriptive purposes only and are used for distinguishing purposes such as substances from one another and are not to be construed as indicating or implying relative importance or to implicitly indicate the number of technical features indicated. For example, a first XX may also be referred to as a second XX, and similarly, a second XX may also be referred to as a first XX, without departing from the scope of embodiments of the present application. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.
As shown in fig. 1, a first aspect of an embodiment of the present application provides a method for manufacturing a flexible pressure sensor, including the following steps:
s10, preparing a first self-repairing hydrogel layer and a second self-repairing hydrogel layer, wherein the first self-repairing hydrogel layer and the second self-repairing hydrogel layer respectively contain moisture;
s20, preparing an electrolyte layer, and respectively attaching a first self-repairing hydrogel layer and a second self-repairing hydrogel layer to the two side surfaces of the electrolyte layer to obtain a pressure sensing layer;
and S30, preparing a first flexible electrode on the surface of the first self-repairing hydrogel layer in the pressure sensing layer, and preparing a second flexible electrode on the surface of the second self-repairing hydrogel layer to obtain the flexible pressure sensor.
According to the preparation method of the flexible pressure sensor provided by the first aspect of the embodiment of the application, two self-repairing hydrogel layers containing water are prepared and respectively attached to the surfaces of the two sides of the electrolyte layer to form the pressure sensing layer with a sandwich structure, and meanwhile, the pressure sensing layer is also a solid electrolyte. And then preparing a flexible electrode on the surface of the self-repairing hydrogel layer of the pressure sensing layer to obtain the flexible pressure sensor. The flexible pressure sensor is designed based on a potential conversion mechanism and has self-repairing and self-powered characteristics. Particularly, on the one hand, the self-repairing hydrogel layers arranged on the two sides can realize the self-repairing performance of the electrolyte layer and the electrode layer through the self-repairing function of hydrogel, so that the flexible pressure sensor has the self-repairing characteristic, the self-repairing effect can be achieved when the flexible pressure sensor is damaged by the outside, and the service life is long. On the other hand, the pressure sensing layer comprises electrolyte layer and the self-repairing hydrogel layer of the water content of setting in its both sides constitutes sandwich structure, the self-repairing hydrogel layer of both sides has certain water content, not only can provide appropriate amount of hydrone for middle electrolyte layer, promote electrolyte layer's ion transmission ability, and can play the effect of encapsulation to middle electrolyte layer, play the water retention effect to electrolyte layer simultaneously, maintain the content of hydrone in electrolyte layer, thereby ensure electrolyte layer's ion transmission ability, need not to carry out extra hydration treatment to electrolyte layer, and need not encapsulation treatment once more, the technology has been simplified. The pressure sensing layer of the sandwich structure is formed by the first self-repairing hydrogel layer, the electrolyte layer and the second self-repairing hydrogel layer, so that when the sensor is stressed, sensing can be realized through the change of intrinsic impedance of the electrolyte layer and the self-repairing hydrogel layer when the sensor is stressed; and the contact resistance of the interface can be changed by changing the contact area of the self-repairing hydrogel layer and the electrode layer, so that pressure sensing is realized. The pressure sensing sensitivity of the flexible pressure sensor can be improved through the combination of the two structures, and the pressure sensing range is expanded.
In some embodiments, in the above step S10, the steps of preparing the first and second self-healing hydrogel layers each independently comprise:
s11, dissolving the self-repairing gel material and the water-absorbing material in a solvent to form precursor slurry.
S12, depositing the precursor slurry on the surface of the substrate, drying to form a film, and placing in an environment with the humidity of 40-70% for 24-48 hours to obtain a first self-repairing hydrogel layer or a second self-repairing hydrogel layer.
According to the preparation method of the self-repairing hydrogel layer, the self-repairing gel material and the water-absorbing material are dissolved in the solvent to form the precursor slurry, wherein the self-repairing gel material provides a self-repairing function, and the water-absorbing material provides water absorption and water retention functions; then depositing the precursor slurry on the surface of the substrate by casting and the like to form a wet film, and drying the wet film to form a dried film. And then the film is placed in an environment with the humidity of 40-70% for 24-48 hours to enable the film to absorb certain moisture, and the self-repairing hydrogel layer with certain moisture content is obtained. When the prepared self-repairing hydrogel layer is broken, non-covalent acting forces such as hydrogen bonds and the like can be formed between damaged materials by utilizing the mobility of a polymer chain, so that cracks are repaired, and the repairing speed can be accelerated under the action of water. If the environment humidity is too high, the water content of the prepared self-repairing hydrogel layer is too high, the conductivity and the ion mobility between the electrolyte layer and the self-repairing hydrogel layer are high, and after the electrolyte is contacted with the electrodes, the potential difference between the two electrodes can quickly reach a saturated state, so that the pressure cannot be sensed. In addition, when the water content of the hydrogel is too high, the difference between the humidity of the hydrogel and the humidity of the air is large, and the hydrogel is not easy to keep stable in the air.
In some embodiments, in step S11, the self-repairing gel material is added into deionized water, stirred at a temperature of 60 to 100 ℃, and after completely dissolved, the water-absorbing material is added to perform stirring treatment, so that the self-repairing gel material and the water-absorbing material are fully dissolved in the deionized water, and then the mixed solution is left for a period of time to eliminate bubbles, and after the bubbles are completely eliminated, a precursor slurry is formed.
In some embodiments, the self-healing gel material comprises at least one of polyvinyl alcohol, chitosan, agar, sodium alginate, polyacrylamide, gelatin; the materials have good self-repairing function. In some embodiments, the self-repairing gel material comprises more than two of polyvinyl alcohol, chitosan, agar, sodium alginate, polyacrylamide and gelatin, and double-network or triple-network hydrogel is formed by compounding the materials, so that the flexible pressure sensor has a better self-repairing effect.
In some embodiments, the water absorbent material comprises at least one of glycerin, ethylene glycol, lithium chloride, magnesium chloride, calcium chloride; the materials have good water absorption performance, so that the self-repairing hydrogel layer has water absorption and water retention properties, water molecules are provided for the electrolyte layer in the flexible pressure sensor, the electron transmission performance of the flexible pressure sensor is improved, the stable content of the water molecules in the electrolyte layer is maintained, the water loss is avoided, and the electron transmission performance of the electrolyte layer is ensured.
In some embodiments, the mass ratio of the self-healing gel material to the water absorbent material is (1-3): (1-2); the proportion not only ensures the self-repairing performance of the self-repairing hydrogel layer, but also ensures the water absorption and water retention performance of the self-repairing hydrogel layer. If the content of the self-repairing gel material is increased, the self-repairing performance of the self-repairing gel material is improved, but the viscosity of the self-repairing hydrogel layer is too high, and demolding of the self-repairing hydrogel layer is not facilitated. In some embodiments, the mass ratio of the self-healing gel material to the water absorbent material includes, but is not limited to, 1.
In some embodiments, the mass fraction of the self-repairing gel material in the precursor slurry is 5-25%; when the concentration of the self-repairing gel material in the precursor slurry is too low, the self-repairing gel material is easy to dehydrate and shrink, and cannot form stable physically-crosslinked hydrogel; when the concentration of the self-repairing gel material is high, the self-repairing gel material is difficult to dissolve in water, and the prepared gel has overlarge modulus and is difficult to deform. In some embodiments, the mass fraction of the self-healing gel material in the precursor slurry includes, but is not limited to, 5-10%, 10-15%, 15-20%, 20-25%, and the like.
In some embodiments, in step S12, the precursor slurry is deposited on the surface of a sand paper or the like by casting or the like, spacers are placed on both sides of the sand paper to control the thickness of the wet film, the wet film is uniformly and flatly coated on the surface of the sand paper by casting, and then the solution is placed in a fume hood together with a mold for 20-48h to be dried and demolded to obtain a film. Then, the film is placed in an environment with the humidity of 40-70% for 24-48 hours, so that the film absorbs certain moisture, and the self-repairing hydrogel layer with a little moisture content is obtained. In the embodiment of the application, the substrate is exemplified by sandpaper with an irregular concave-convex microstructure, and a microstructure on the surface of a self-repairing hydrogel layer can be constructed by using substrates such as natural or artificial templates with regular concave-convex structures, such as micro pyramids, micro spheres, micro columns and the like. The microstructure can regulate and control contact resistance, and when the microstructure deforms under stress, the contact area can be changed, so that the contact resistance can be regulated and controlled.
In some embodiments, the substrate is selected from sandpaper having a surface mesh size of 1000 to 10000 meshes, such that the first and second self-healing hydrogel layers have microstructures on the surface of the layer contacting the sandpaper. According to the embodiment of the application, the microstructure is constructed on the surface of the self-repairing hydrogel layer, so that when a device is under pressure, the contact area between the electrolyte layer and the electrode layer is increased, the interface contact resistance is changed, and pressure sensing is realized. The sand paper with the surface mesh number is used as a substrate, can prepare a self-repairing hydrogel layer with rich microstructures on the surface, is favorable for improving the pressure sensing sensitivity of the flexible pressure sensor and expanding the pressure sensing range
In some embodiments, the first self-healing hydrogel layer and the second self-healing hydrogel layer each independently have a water content of 5 to 35wt%. Because the realization of the potential conversion mechanism of the electrolyte layer depends on the ion transmission capability of the electrolyte, the completely dehydrated graphene oxide and other electrolyte layers are equivalent to dielectric layers and have no electrolyte property, and the insertion of water molecules is favorable for improving the ion transmission capability of the electrolyte layer, so that the electrolyte layer is required to have certain water content and cannot be dehydrated under the influence of the environment. The self-repairing hydrogel layer on the two sides of the electrolyte layer comprises certain moisture, water molecules can be provided for the electrolyte layer, and the electrolyte layer is guaranteed to have better ion transmission capacity under participation of the water molecules. Meanwhile, the self-repairing hydrogel layer also has water retention performance, and can ensure that water molecules in the electrolyte layer are not lost, so that the electron transmission stability of the electrolyte layer is ensured. If the water content in the self-repairing hydrogel layer is too low, fewer water molecules are captured by the electrolyte layer, the ion transmission capability is poor, and the lower water content causes the network density of the hydrogel polymer in the self-repairing hydrogel layer to be increased, so that the ion transmission in the self-repairing hydrogel layer is hindered, the ion transmission capability between the self-repairing hydrogel layer and the electrolyte layer is poor, and a potential conversion mechanism cannot be realized; if when water content was too high in the selfreparing hydrogel layer, the conductivity and the ion mobility of electrolyte layer and selfreparing hydrogel layer were higher, and after electrolyte and electrode contacted, the potential difference between two electrodes can reach saturated state fast to can't sense pressure, in addition, selfreparing hydrogel layer water content when too big its with air humidity differ great, be difficult for keeping flexible pressure sensor's stability in the air. In some embodiments, the first self-healing hydrogel layer and the second self-healing hydrogel layer each independently have a water content of 5 to 10wt%, 10 to 15wt%, 15 to 20wt%, 20 to 25wt%, 25 to 30wt%, 30 to 35wt%, and the like.
In some embodiments, the thicknesses of the first self-repairing hydrogel layer and the second self-repairing hydrogel layer are respectively and independently 0.2-3 mm, and the thickness interval is favorable for ensuring the detection sensitivity of the flexible pressure sensor. If the thickness of the self-repairing hydrogel layer is too small, the deformation space is too low, and the water retention capacity is limited; if the thickness of the self-repairing hydrogel layer is too large, the self-repairing hydrogel layer is not easy to deform, and the sensitivity is reduced. In some embodiments, the thicknesses of the first and second self-repairing hydrogel layers are, independently, 0.2 to 0.5mm, 0.5 to 0.8mm, 0.8 to 1mm, 1 to 1.5mm, 1.5 to 2mm, 2 to 2.5mm, 2.5 to 3mm, and the like.
In some embodiments, in the step S20, the step of preparing the electrolyte layer includes: the electrolyte material is dispersed in water to form a dispersion, and the dispersion is made into an electrolyte layer by a suction filtration method. In some embodiments, a certain mass of electrolyte material is added into deionized water for ultrasonic treatment for a certain time to ensure that the electrolyte material is fully dispersed, and then a membrane is prepared from the electrolyte material dispersion liquid by adopting a suction filtration method and is cut into a certain size for later use. In addition, the electrolyte layer may be prepared by spraying, printing, or the like.
In some embodiments, the electrolyte material comprises at least one of graphene oxide, a metal-organic framework material, a covalent organic framework, hexagonal boron nitride, molybdenum disulfide, tungsten disulfide; the electrolyte materials all have a two-dimensional lamellar structure, can perform self-assembly action in the film forming process, and are easy to form an electrolyte layer with a microstructure. The microstructure can regulate and control contact resistance, and when the microstructure deforms under stress, the contact resistance can be regulated and controlled by changing the contact area. In some preferred embodiments, the electrolyte material is selected from graphene oxide.
In some embodiments, the concentration of the dispersion is 2 to 7mg/ml; the dispersion liquid with the concentration is beneficial to improving the efficiency of preparing the electrolyte layer by using a suction filtration method, and if the concentration is too low, the suction filtration time is long, and the preparation efficiency is low; if the concentration is too high, the prepared electrolyte layer film is uneven and uneven in thickness. In some embodiments, the concentration of the dispersion includes, but is not limited to, 2mg/ml, 3mg/ml, 4mg/ml, 5mg/ml, 6mg/ml, 7mg/ml, and the like.
In some embodiments, the electrolyte layer has a thickness of 0.01 to 1mm. When the thickness of the electrolyte layer is smaller, the number of stacked layers is smaller, the layered microstructure is easy to saturate under smaller pressure, and the sensitivity of the device is reduced; the preparation of an electrolyte layer with an excessively high thickness increases the cost, and also increases an ion transmission path, thereby reducing the detection sensitivity of the device to a certain extent. In some embodiments, the thickness of the electrolyte layer includes, but is not limited to, 0.01 to 0.1mm, 0.1 to 0.2mm, 0.2 to 0.5mm, 0.5 to 0.8mm, 0.8 to 1mm, and the like.
In some embodiments, the step of attaching the first and second self-healing hydrogel layers to the respective side surfaces of the electrolyte layer comprises: and (3) setting the surfaces of one sides with the microstructures in the first self-repairing hydrogel layer and the second self-repairing hydrogel layer to be away from the electrolyte layer. Under this condition, the one side surface that has the microstructure in the self-healing hydrogel layer sets up with the contact of flexible electrode layer, and the contact resistance can be regulated and control to the microstructure that self-healing hydrogel layer surface has, and when the deformation takes place for the microstructure atress, the accessible changes area of contact, and then regulates and control contact resistance. In addition, the surface of the self-repairing hydrogel layer attached to the electrolyte layer is a flat surface, so that water molecules required by ion transmission can be provided for the electrolyte layer, a better packaging effect can be formed on the electrolyte layer, and the water molecules in the electrolyte layer are prevented from losing easily.
In some embodiments, multiple pressure sensing layers can be laminated together to form a composite pressure sensing layer, e.g., two or more pressure sensing layers can be laminated together through an outer self-healing hydrogel layer to form a composite self-healing hydrogel layer. The electrolyte layer and the self-repairing hydrogel layer can be sequentially attached to the surface of the self-repairing hydrogel layer on the outer side of the pressure sensing layer to form the composite pressure sensing layer.
In some embodiments, in the step S30, the preparing of the first flexible electrode and the second flexible electrode independently comprises: dissolving or dispersing the electrode material into water, and preparing the flexible electrode layer by adopting a suction filtration method. Besides, the dispersion liquid of the electrode material can be deposited on the surface of the self-repairing hydrogel layer by using methods such as spraying, ink-jet printing, magnetron sputtering and the like to prepare the flexible electrode.
In some embodiments, a first flexible electrode is prepared on the surface of a first self-repairing hydrogel layer in the pressure sensing layer, and a second flexible electrode is prepared on the surface of a second self-repairing hydrogel layer. The laminating of first flexible electrode sets up on the surface of first selfreparing hydrogel layer, and the laminating of second flexible electrode sets up on the surface of second selfreparing hydrogel layer. The pressure sensing layer and the flexible electrolytic attachment are arranged, when the flexible pressure sensor is damaged accidentally, the self-repairing function of hydrogel can be utilized, and the self-repairing of the electrolyte layer and the flexible electrode layer is realized.
In some embodiments, electrode materials with different chemical potentials are used in the first flexible electrode and the second flexible electrode. Two conductive materials with different chemical potentials are selected to be respectively made into a first flexible electrode and a second flexible electrode, so that the potential conversion type pressure sensing can be realized.
In some embodiments, the electrode material comprises at least one of carbon nanotubes, graphene, MXene, metal nanowires, metal nanoparticles; the materials have good conductivity, and are favorable for conducting charges when used as electrode materials, so that the device can sensitively detect pressure.
In some embodiments, the thicknesses of the first flexible electrode and the second flexible electrode are respectively and independently 0.005-1 mm, and under the thicknesses, the electrode thickness is moderate, the self resistance is small, the electrode can be kept stable in a certain deformation range, and the repair efficiency is high after fracture. When the flexible electrode is thin, the self resistance of the electrode is large, so that the sensitivity of the device is low, and the self-repairing efficiency is low; when the flexible electrode is too thick, the part far away from the self-repairing hydrogel layer cannot be self-repaired, materials are wasted, the overall modulus of the device is high, deformation is not prone to occurring, and the sensitivity is low.
As shown in fig. 2, a second aspect of the embodiment of the present application provides a flexible pressure sensor, which includes a first flexible electrode, a composite pressure sensing layer, and a second flexible electrode, which are sequentially attached to each other; the composite pressure sensing layer at least comprises a pressure sensing layer formed by sequentially attaching a first self-repairing hydrogel layer, an electrolyte layer and a second self-repairing hydrogel layer; wherein, the first self-repairing hydrogel layer and the second self-repairing hydrogel layer respectively contain moisture.
According to the flexible pressure sensor provided by the second aspect of the embodiment of the application, the flexible pressure sensor is designed based on a potential conversion mechanism, the self-repairing hydrogel layers arranged on two sides of the electrolyte layer are arranged in the pressure sensing layer, the self-repairing performance of the electrolyte layer and the electrode layer can be realized, the flexible pressure sensor has a self-repairing characteristic, the self-repairing effect can be achieved when the flexible pressure sensor is damaged by the outside, and the flexible pressure sensor is long in service life. Meanwhile, the self-repairing hydrogel layers on the two sides have certain water content, water molecules required for ion transmission can be provided for the middle electrolyte layer, a water retention effect can be achieved on the electrolyte layer, and the ion transmission capability of the electrolyte layer is ensured. The flexible pressure sensor has self-repairing and self-power-supplying characteristics through the synergistic effect of the functional layers. When external pressure is applied, sensing can be realized through the change of intrinsic impedance of the electrolyte layer and the self-repairing hydrogel layer when the electrolyte layer and the self-repairing hydrogel layer are pressed; and the contact resistance of the interface can be changed by changing the contact area of the self-repairing hydrogel layer and the electrode layer, so that pressure sensing is realized. The pressure sensing sensitivity is high, and the pressure sensing range is wide.
The flexible pressure sensor of the embodiment of the application can be manufactured by the method of the embodiment.
In some embodiments, the composite pressure sensing layer includes more than two pressure sensing layers sequentially laminated by the first self-repairing hydrogel layer, the electrolyte layer and the second self-repairing hydrogel layer, and the composite pressure sensing layer can be obtained by compounding the two pressure sensing layers with the same structure. Because the self-repairing hydrogel layers have excellent bonding performance, the adjacent self-repairing hydrogel layers can quickly form a whole after being bonded. In other embodiments, more than two pressure sensing layers to be combined are combined, one of the pressure sensing layers may also be provided with a self-repairing hydrogel layer only on one side of the electrolyte layer, but when the two pressure sensing layers are combined, the two pressure sensing layers can be bonded together through one of the composite pressure sensing layers to form a composite pressure sensing layer whole. In some embodiments, the flexible pressure sensor is shown in fig. 3, and includes a first flexible electrode, a composite pressure sensing layer, and a second flexible electrode sequentially attached to each other, where the composite pressure sensing layer includes a sub-pressure sensing layer formed by sequentially attaching a first self-repairing hydrogel layer, a first electrolyte layer, and a second self-repairing hydrogel layer, and includes another sub-pressure sensing layer formed by sequentially attaching a second electrolyte layer and a third self-repairing hydrogel layer.
In some embodiments, one side surface of the first and second self-repairing hydrogel layers has a microstructure, and the one side surface of the first and second self-repairing hydrogel layers having the microstructure is disposed away from the electrolyte layer.
In some embodiments, the first self-healing hydrogel layer and the second self-healing hydrogel layer each independently have a water content of 5 to 35wt%.
In some embodiments, each of the first flexible electrode and the second flexible electrode independently includes at least one electrode material selected from the group consisting of carbon nanotubes, graphene, MXene, metal nanowires, and metal nanoparticles, and the first flexible electrode and the second flexible electrode include electrode materials having different chemical potentials.
In some embodiments, the first self-healing hydrogel layer and the second self-healing hydrogel layer each independently comprise a mass ratio of (1-3): the self-healing gel material and the water-absorbent material according to (1) to (2).
In some embodiments, the electrolyte layer includes at least one electrolyte material of graphene oxide, metal-organic framework material, covalent organic framework, hexagonal boron nitride, molybdenum disulfide, tungsten disulfide.
In some embodiments, the area of the electrolyte layer is slightly smaller than the area of the self-repairing hydrogel layer, ensuring that the self-repairing hydrogel layer can sufficiently cope with the deformation of the electrolyte layer and repair the electrolyte layer.
In some embodiments, the first compliant electrode and the second compliant electrode each independently have a thickness of 0.005 to 1mm.
In some embodiments, the first self-healing hydrogel layer and the second self-healing hydrogel layer each independently have a thickness of 0.2 to 3mm.
In some embodiments, the electrolyte layer has a thickness of 0.01 to 1mm.
The beneficial effects of the above embodiments of the present application are discussed in detail in the foregoing, and are not described herein again.
In order to make the above implementation details and operations of the present application clearly understandable to those skilled in the art and to make the flexible pressure sensor and the manufacturing method thereof according to the embodiments of the present application remarkably show the advanced performance, the above technical solution is exemplified by a plurality of embodiments.
Example 1
A flexible pressure sensor is shown in the attached figure 2, and comprises a first flexible electrode, a first self-repairing hydrogel layer, an electrolyte layer, a second self-repairing hydrogel layer and a second flexible electrode which are sequentially laminated and attached; the first flexible electrode and the second flexible electrode are electrically connected with a voltmeter.
The preparation method comprises the following steps:
1. preparing a polyvinyl alcohol PVA/glycerol Gly hydrogel precursor: adding PVA powder with a certain mass into deionized water, stirring at the temperature of 80 ℃, controlling the mass fraction of PVA to be 10%, after the PVA powder is completely dissolved, adding Gly with a certain mass into the PVA water solution, stirring for 10min, controlling the mass ratio of Gly to PVA to be 1, standing the mixed solution for a period of time to eliminate bubbles, and after the bubbles are completely eliminated, obtaining a PVA/Gly hydrogel precursor.
2. Preparing a self-repairing PVA/Gly hydrogel layer: pouring the prepared PVA/Gly hydrogel precursor on the surface of sand paper, placing gaskets on two sides of the sand paper (the mesh number of the sand paper is 2000 meshes) to control the thickness of the film to be 0.3mm, uniformly and flatly coating the film on the surface of the sand paper by a tape casting method, then placing the solution and a mould in a fume hood for 24h, tearing the film after gelling to obtain a PVA/Gly hydrogel layer with a microstructure on the surface, and then placing the PVA/Gly hydrogel layer in an environment with the humidity of 56% for 24h to obtain a self-repairing hydrogel layer with the water content of 15%, namely a first self-repairing hydrogel layer and a second self-repairing hydrogel layer.
3. Preparation of GO electrolyte: adding a certain mass of GO into deionized water for ultrasonic treatment for 20min, wherein the concentration of GO is 3mg/ml, preparing a GO dispersion liquid into a film by adopting a suction filtration method, and cutting the film appropriately, wherein the thickness of the prepared GO film is 0.1mm, namely an electrolyte layer.
4. Preparation of CNT and MXexe electrodes: and (2) adding a certain mass of CNT (carbon nano tube) and MXene into n-hexane and deionized water respectively for ultrasonic treatment for 30min, and then preparing CNT and MXene dispersion liquid into films respectively by adopting a suction filtration method and cutting the films appropriately. The thickness of the prepared CNT electrode film and the MXene electrode film is 0.005mm, namely the first electrode and the second electrode respectively.
5. Assembling a device: the prepared GO film is clamped between two layers of self-repairing PVA/Gly hydrogel layers (the area of the GO film is smaller than that of the PVA/Gly hydrogel film), one side of the hydrogel with a microstructure is back to the GO, then CNT and MXene electrodes are attached to the self-repairing PVA/Gly hydrogel layers on the two sides respectively to form a self-repairing flexible pressure sensor, and leads are led out from the two electrode ends respectively to connect the device with testing equipment so as to finish testing.
Example 2
A flexible pressure sensor comprises a first flexible electrode, a first self-repairing hydrogel layer, an electrolyte layer, a second self-repairing hydrogel layer and a second flexible electrode which are sequentially laminated and attached; the preparation steps and the adopted materials of the first flexible electrode, the first self-repairing hydrogel layer, the electrolyte layer, the second self-repairing hydrogel layer and the second flexible electrode are the same as those in embodiment 1. The difference points are that: the mass fraction of PVA in the first self-repairing hydrogel layer and the second self-repairing hydrogel layer is 15%.
Example 3
A flexible pressure sensor is shown in figure 3, and comprises a first flexible electrode, a first self-repairing hydrogel layer, a first electrolyte layer, a second self-repairing hydrogel layer, a second electrolyte layer, a third self-repairing hydrogel layer and a second flexible electrode which are sequentially laminated and attached; the preparation steps and the adopted materials of the first flexible electrode and the second flexible electrode are the same as those in the embodiment 1, the preparation steps and the adopted materials of the first electrolyte layer and the second electrolyte layer are the same as those in the embodiment 1, and the preparation steps and the adopted materials of the first self-repairing hydrogel layer, the second self-repairing hydrogel layer and the third self-repairing hydrogel layer are the same as those in the embodiment 1. The difference points are that: the first self-repairing hydrogel layer was prepared using the same process as in example 1, except that the mold used was a silicon wafer having a pyramidal structure.
Comparative example 1
A flexible pressure sensor comprises a first flexible electrode, an electrolyte layer and a second flexible electrode which are sequentially laminated and attached; the preparation steps and the materials used for the first flexible electrode, the electrolyte layer and the second flexible electrode are the same as those in example 1.
Comparative example 2
A flexible pressure sensor comprises a first flexible electrode, a self-repairing hydrogel layer and a second flexible electrode which are sequentially laminated and attached; the preparation steps and the adopted materials of the first flexible electrode, the self-repairing hydrogel layer and the second flexible electrode are the same as those in the embodiment 1.
Comparative example 3
A flexible pressure sensor comprises a first flexible electrode, a self-repairing hydrogel layer, an electrolyte layer and a second flexible electrode which are sequentially laminated and attached; the preparation steps and the adopted materials of the first flexible electrode, the self-repairing hydrogel layer, the electrolyte layer and the second flexible electrode are the same as those in the embodiment 1.
Further, to verify the advancement of the examples of the present application, the following performance tests were performed:
1. for the flexible pressure sensor prepared in example 1, the magnitude of the output voltage signal was measured at constant cycle pressures of 2kPa, 5kPa, and 10kPa, respectively. Example 1 output voltage signals of the flexible pressure sensor under constant cyclic pressures of 2kPa, 5kPa and 10kPa respectively are shown in fig. 4, and it can be seen from the figure that the flexible pressure sensor of the present application can realize stable sensing of static forces of different magnitudes.
In addition, the flexible pressure sensor in the embodiment 1 is processed to be broken, then a small amount of deionized water is coated on the broken part, the spliced section sensor can be healed again, and after redundant water is evaporated, a voltage signal is output under the constant circulating pressure of 10 kPa. As shown in FIG. 5, it can be seen that the sensor can still stably sense, indicating the good self-repairing performance of the sensor.
2. The pressure sensing sensitivity of the flexible pressure sensors prepared in each of the examples and comparative examples was tested: the method comprises the steps of applying different pressures to a sensor by using a mechanical testing platform, synchronously measuring output voltage signals, and then calculating the sensitivity according to a formula S = delta V/delta P, wherein delta V is a variation value of the output voltage, and delta P is a variation value of pressure intensity.
3. The self-repair performance of the flexible pressure sensors prepared in the examples and the comparative examples was tested: the flexible pressure sensor is processed to be broken, a small amount of deionized water is smeared at the broken part, whether the sensor is healed again or not is observed after the section is spliced, and after redundant water of the sensor to be healed is evaporated, the sensing sensitivity of the flexible pressure sensor is measured and compared with the pressure sensing sensitivity before self-repairing.
The test results are shown in table 1 below.
TABLE 1
According to the test results, the self-repairing hydraulic layer serves as the pressure sensing layer with the surface microstructure, the water retaining layer capable of providing and retaining water for the electrolyte layer can be provided, and the pressure sensing sensitivity and the self-repairing performance of the flexible pressure sensor are greatly affected. As can be seen from a comparison of the test results of example 1 and example 2, the pressure sensing sensitivity is reduced after the mass fraction of PVA in the hydrogel is increased, because the elastic modulus of the hydrogel is increased, which is disadvantageous to deformation and thus reduces the sensitivity. As can be seen from comparison between the test results of example 1 and example 3, the increase of the laminated structure is beneficial to increase the deformation space and thus the pressure sensing sensitivity. It can be seen from comparison of the test results of example 1 and comparative example 2 that the flexible pressure sensor without the GO electrolyte layer can also realize pressure sensing by virtue of the ion transport capability of the self-repairing hydrogel layer, but the pressure sensitivity thereof is reduced due to the loss of the layered microstructure of GO. The self-repairing performance of the embodiments 1, 2, 3 and 2 can be realized due to the self-repairing hydrogel layer, and the pressure sensing sensitivity of the embodiments is almost unchanged from that before self-repairing. Compared with the prior art, the self-repairing hydrogel layer does not exist in the comparative example 1, so that self-repairing of the device cannot be realized, water molecules cannot be provided for the GO electrolyte layer, the dehydrated GO electrolyte layer is equivalent to a dielectric layer, the electrolyte property is not possessed, ion transmission cannot be carried out, and pressure sensing of a potential conversion mechanism cannot be realized. Comparative example 3 because only one deck aquogel, second flexible electrode do not have with selfreparing aquogel layer in close contact with, do not wrap up GO electrolyte layer completely, consequently GO electrolyte layer can't preserve water, GO electrolyte layer dewaters easily, is equivalent to the dielectric layer, does not have the electrolyte property, can't carry out ion transmission, consequently also can't realize the pressure sensing of potential conversion mechanism. And meanwhile, the self-repairing performance of the whole device cannot be shown.
The above description is only a preferred embodiment of the present application and should not be taken as limiting the present application, and any modifications, equivalents, improvements, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.
Claims (10)
1. A preparation method of a flexible pressure sensor is characterized by comprising the following steps:
preparing a first self-repairing hydrogel layer and a second self-repairing hydrogel layer, wherein the first self-repairing hydrogel layer and the second self-repairing hydrogel layer respectively contain moisture;
preparing an electrolyte layer, and respectively attaching the first self-repairing hydrogel layer and the second self-repairing hydrogel layer to the two side surfaces of the electrolyte layer to obtain a pressure sensing layer;
and preparing a first flexible electrode on the surface of the first self-repairing hydrogel layer in the pressure sensing layer, and preparing a second flexible electrode on the surface of the second self-repairing hydrogel layer to obtain the flexible pressure sensor.
2. The method of making a flexible pressure sensor of claim 1, wherein the steps of making the first self-healing hydrogel layer and the second self-healing hydrogel layer each independently comprise:
dissolving a self-repairing gel material and a water-absorbing material in a solvent to form precursor slurry;
and depositing the precursor slurry on the surface of the substrate, drying to form a film, and standing in an environment with the humidity of 40-70% for 24-48 hours to obtain the first self-repairing hydrogel layer or the second self-repairing hydrogel layer.
3. The method of claim 2, wherein the self-healing gel material comprises at least one of polyvinyl alcohol, chitosan, agar, sodium alginate, polyacrylamide, and gelatin;
and/or the water-absorbing material comprises at least one of glycerol, glycol, lithium chloride, magnesium chloride and calcium chloride;
and/or the mass ratio of the self-repairing gel material to the water-absorbing material is (1-3): (1-2);
and/or, in the precursor slurry, the mass fraction of the self-repairing gel material is 5-25%;
and/or the substrate is selected from sand paper with the surface mesh number of 1000-10000 meshes, so that the surfaces of one sides of the first self-repairing hydrogel layer and the second self-repairing hydrogel layer, which are in contact with the sand paper, have microstructures;
and/or the water content of the first self-repairing hydrogel layer and the water content of the second self-repairing hydrogel layer are respectively and independently 5-35 wt%;
and/or the thicknesses of the first self-repairing hydrogel layer and the second self-repairing hydrogel layer are respectively and independently 0.2-3 mm.
4. The method of making a flexible pressure sensor of claim 3, wherein the step of attaching the first self-healing hydrogel layer and the second self-healing hydrogel layer to respective sides of the electrolyte layer comprises: and arranging the surfaces of one sides of the first self-repairing hydrogel layer and the second self-repairing hydrogel layer, which are provided with the microstructures, away from the electrolyte layer.
5. The method of manufacturing a flexible pressure sensor according to any one of claims 1 to 4, wherein the step of manufacturing the electrolyte layer includes: dispersing an electrolyte material into water to form a dispersion liquid, and preparing the dispersion liquid into the electrolyte layer by a suction filtration method.
6. The method of claim 5, wherein the electrolyte material comprises at least one of graphene oxide, a metal-organic framework material, a covalent organic framework, hexagonal boron nitride, molybdenum disulfide, tungsten disulfide;
and/or the concentration of the dispersion liquid is 2-7 mg/ml;
and/or the thickness of the electrolyte layer is 0.01-1 mm.
7. The method of manufacturing a flexible pressure sensor according to claim 1 or 6, wherein the manufacturing of the first flexible electrode and the second flexible electrode each independently comprises the steps of: dissolving or dispersing the electrode material into water, and preparing the flexible electrode layer by adopting a suction filtration method;
and/or electrode materials with different chemical potentials are adopted in the first flexible electrode and the second flexible electrode.
8. The method of claim 7, wherein the electrode material comprises at least one of carbon nanotubes, graphene, MXene, metal nanowires, and metal nanoparticles;
and/or the thicknesses of the first flexible electrode and the second flexible electrode are respectively and independently 0.005-1 mm.
9. The flexible pressure sensor is characterized by comprising a first flexible electrode, a composite pressure sensing layer and a second flexible electrode which are sequentially attached; the composite pressure sensing layer at least comprises a pressure sensing layer formed by sequentially attaching a first self-repairing hydrogel layer, an electrolyte layer and a second self-repairing hydrogel layer; wherein the first and second self-healing hydrogel layers each contain moisture.
10. The flexible pressure sensor of claim 9, wherein one side surface of the first and second self-healing hydrogel layers has a microstructure, and wherein the one side surface of the first and second self-healing hydrogel layers having the microstructure is disposed away from the electrolyte layer;
and/or the water content of the first self-repairing hydrogel layer and the water content of the second self-repairing hydrogel layer are respectively and independently 5-35 wt%;
and/or the first flexible electrode and the second flexible electrode respectively and independently comprise at least one electrode material of carbon nanotubes, graphene, MXene, metal nanowires and metal nanoparticles, and the first flexible electrode and the second flexible electrode comprise electrode materials with different chemical potentials;
and/or the first self-repairing hydrogel layer and the second self-repairing hydrogel layer respectively and independently comprise the following components in a mass ratio of (1-3): (1-2) the self-healing gel material and the water-absorbent material;
and/or the electrolyte layer comprises at least one electrolyte material of graphene oxide, metal-organic framework material, covalent organic framework, hexagonal boron nitride, molybdenum disulfide and tungsten disulfide;
and/or the thicknesses of the first flexible electrode and the second flexible electrode are respectively and independently 0.005-1 mm;
and/or the thicknesses of the first self-repairing hydrogel layer and the second self-repairing hydrogel layer are respectively and independently 0.2-3 mm;
and/or the thickness of the electrolyte layer is 0.01-1 mm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210914993.8A CN115468687A (en) | 2022-08-01 | 2022-08-01 | Flexible pressure sensor and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210914993.8A CN115468687A (en) | 2022-08-01 | 2022-08-01 | Flexible pressure sensor and preparation method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115468687A true CN115468687A (en) | 2022-12-13 |
Family
ID=84367353
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210914993.8A Pending CN115468687A (en) | 2022-08-01 | 2022-08-01 | Flexible pressure sensor and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115468687A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116942099A (en) * | 2023-07-31 | 2023-10-27 | 华南理工大学 | Swallowing monitoring system and method based on myoelectricity and pressure sensing |
| CN117064363A (en) * | 2023-08-21 | 2023-11-17 | 华南农业大学 | Multimode respiration sensor and preparation method thereof |
-
2022
- 2022-08-01 CN CN202210914993.8A patent/CN115468687A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116942099A (en) * | 2023-07-31 | 2023-10-27 | 华南理工大学 | Swallowing monitoring system and method based on myoelectricity and pressure sensing |
| CN116942099B (en) * | 2023-07-31 | 2024-03-19 | 华南理工大学 | Swallowing monitoring system and method based on myoelectricity and pressure sensing |
| CN117064363A (en) * | 2023-08-21 | 2023-11-17 | 华南农业大学 | Multimode respiration sensor and preparation method thereof |
| CN117064363B (en) * | 2023-08-21 | 2024-03-22 | 华南农业大学 | Multimode respiration sensor and preparation method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN115468687A (en) | Flexible pressure sensor and preparation method thereof | |
| Li et al. | Sodium alginate reinforced polyacrylamide/xanthan gum double network ionic hydrogels for stress sensing and self-powered wearable device applications | |
| Hu et al. | Transparent, conductive cellulose hydrogel for flexible sensor and triboelectric nanogenerator at subzero temperature | |
| Lin et al. | One-pot synthesis of a double-network hydrogel electrolyte with extraordinarily excellent mechanical properties for a highly compressible and bendable flexible supercapacitor | |
| Chen et al. | Flexible, conductive, and anisotropic thermoplastic polyurethane/polydopamine/MXene foam for piezoresistive sensors and motion monitoring | |
| Chen et al. | Highly flexible and adhesive poly (vinyl alcohol)/poly (acrylic amide-co-2-acrylamido-2-methylpropane sulfonic acid)/glycerin hydrogel electrolyte for stretchable and resumable supercapacitor | |
| Ding et al. | Stretchable, self‐healable, and breathable biomimetic iontronics with superior humidity‐sensing performance for wireless respiration monitoring | |
| Wei et al. | Highly stretchable, fast self‐healing, responsive conductive hydrogels for supercapacitor electrode and motion sensor | |
| Fard et al. | PVA-based supercapacitors | |
| Song et al. | Totally dynamically cross-linked dual-network conductive hydrogel with superb and rapid self-healing ability for motion detection sensors | |
| Xie et al. | Flexible electronic skin sensor based on regenerated cellulose/carbon nanotube composite films | |
| Zhang et al. | Stretchable and conductive cellulose hydrogel electrolytes for flexible and foldable solid-state supercapacitors | |
| CN111562038A (en) | Flexible capacitive pressure sensor and flexible capacitive pressure array sensor | |
| CN106461473A (en) | Surface area-based pressure sensing | |
| Kim et al. | A rationally designed flexible self-healing system with a high performance supercapacitor for powering an integrated multifunctional sensor | |
| Mohanta et al. | Stretchable electrolytes for stretchable/flexible energy storage systems–Recent developments | |
| Mondal et al. | Preparation of lignosulfonate ionic hydrogels for supercapacitors, sensors and dye adsorbent applications | |
| WO2023004930A1 (en) | Zwitterionic anti-freezing organic hydrogel, preparation method therefor, and use thereof | |
| Zhu et al. | Antifreezing ionotronic skin based on flexible, transparent, and tunable ionic conductive nanocellulose hydrogels | |
| Mir et al. | A short review on the synthesis and advance applications of polyaniline hydrogels | |
| Yamada | A transient supercapacitor with a water-dissolvable ionic gel for sustainable electronics | |
| Zhou et al. | A flexible hydrogel tactile sensor with low compressive modulus and dynamic piezoresistive response regulated by lignocellulose/graphene aerogels | |
| Ma et al. | Integrating MXene waste materials into value-added products for smart wearable self-powered healthcare monitoring | |
| Jeong | Electrochemical performances of semi-transparent and stretchable supercapacitor composed of nanocarbon materials | |
| Hou et al. | High strength and toughness poly (vinyl alcohol)/gelatin double network hydrogel fabricated via Hofmeister effect for polymer electrolyte |
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 |