CN117451225A - Wearable and washable piezoresistive pressure sensor and preparation method and application thereof - Google Patents
Wearable and washable piezoresistive pressure sensor and preparation method and application thereof Download PDFInfo
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Classifications
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- 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
- G01L5/00—Apparatus for, or methods of, measuring force, work, mechanical power, or torque, specially adapted for specific purposes
- G01L5/0028—Force sensors associated with force applying means
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Abstract
The invention provides a wearable and washable piezoresistive pressure sensor, a preparation method and application thereof, and relates to the technical field of flexible wearable equipment. According to the method, CNT/CB is attached to the skeleton of the PU sponge through impregnation, and further after TPU particles are melted at high temperature, CNT and CB are firmly combined together to form the CNT/CB/TPU@PU sensor, and the sensor has good sensitivity, stability and washability. The force sensitive layer of the sensor of the invention is significantly washable; due to the conductive network cooperatively constructed by the CNT and the CB, the sensor is realized in the sensitivity (0.1 KPa ‑1 ) Response time (119 ms), recovery time (59 ms), repeatability (1000), and stability. The sensor has great application potential in the aspect of real-time detection of human health and human-computer interface interaction.
Description
Technical Field
The invention relates to the technical field of flexible wearable equipment, in particular to a wearable and washable piezoresistive pressure sensor, and a preparation method and application thereof.
Background
In recent years, flexible and wearable pressure/strain sensors have received attention because of their increasing demands in human motion monitoring, human-machine interaction, soft electronic skin, and the like. Flexible pressure sensors can be classified into piezoresistive type, piezoelectric type and capacitive type according to different sensing mechanisms, wherein piezoresistive type sensors are widely studied due to the advantages of high sensitivity, fast response, simple preparation and low cost. The key to the fabrication of piezoresistive sensors is generally the design of the sensor structure and the choice of conductive materials. The sensor microstructure is in a thorn shape, a three-dimensional structure, a bionic structure and the like. Conductive materials can be divided into three types: the zero-dimensional material has CB particles (the surface of the conductive carbon black particles contains a plurality of polar groups such as carboxyl-COOH and hydroxyl-OH) and metal nano particles, the one-dimensional material has carbon nano tubes, and the two-dimensional material has graphene, mxene and the like. Flexible piezoresistive sensors are prepared by dispersing conductive fillers into high molecular polymers (rubber, polydimethylsiloxane, polyurethane, etc.). However, such conductive rubber/film sensors are unstable in performance and accurate detection at low pressures (< 10 kPa) is difficult to achieve.
The sponge has rich three-dimensional porous structure and is widely applied to flexible pressure sensors. The porous framework provides abundant attachment areas for the conductive material, a layer of conductive material is covered on the three-dimensional framework to form a conductive network with a three-dimensional structure, and the three-dimensional framework can generate larger electric signal change after being deformed under pressure. The sponge has good flexibility and restorability, which makes it a rational flexible sensor base material. Based on this strategy, the selection of suitable conductive materials, such as CNT, CB, metal nanoparticles, graphene, etc., becomes critical. The research shows that the sensor constructed by the zero-dimensional material CB has good sensitivity, because the conductive network formed by CB particles can be quickly rebuilt under the action of external force, larger electric signal change is caused, CNTs have large length-diameter ratio, and the conductive network formed by contact between CNTs can be changed greatly when the external force is larger. Combining the two, and simultaneously taking the CNT and the CB as the sensing layer material of the sensor, the performance of the sensor can be effectively improved.
Based on the above, development of a wearable and washable piezoresistive pressure sensor with high sensitivity and a preparation method and application thereof are needed at present, so that the high requirement of wearable electronic equipment on the stability of the washable piezoresistive pressure sensor is met, and the urgent market demands are met.
Disclosure of Invention
The invention provides a wearable and washable piezoresistive pressure sensor, a preparation method and application thereof, and aims to solve the problems in the prior art.
In order to achieve the above purpose, the embodiment of the invention provides a wearable and washable piezoresistive pressure sensor, a preparation method and application thereof, CNT/CB is attached to a framework of a sponge through impregnation, further TPU particles are melted at high temperature to firmly combine CNT and CB together to form the CNT/CB/TPU@PU sensor, and the sensor has good sensitivity, stability and washability. The force sensitive layer of the sensor of the present invention is significantly washable because the TPU particles firmly bind the CNT and CB together after melting at high temperatures. Secondly, thanks to the conductive network cooperatively constructed by the CNT and the CB, the sensor is realized in the sensitivity (0.1 KPa -1 ) Response time (119 ms), recovery time (59 ms), repeatability (1000), and stability. By virtue of the good performances, the sensor has great application potential in the aspect of real-time detection of human health and human-machine interface interaction.
The embodiment of the invention provides a preparation method of a wearable and washable piezoresistive pressure sensor, which comprises the following steps:
s1: cutting the sponge into square blocks by a cutting machine, respectively ultrasonically cleaning the sponge blocks in deionized water and absolute ethyl alcohol, and drying for later use;
s2: adding CB particles into the CNT solution, and magnetically stirring to obtain a uniform CNT/CB solution for standby;
s3: immersing the washed and dried sponge block into a CNT/CB solution, repeatedly squeezing the sponge block to ensure full immersion, taking out, and putting into a constant-temperature drying oven for drying;
s4: dispersing TPU powder into absolute ethyl alcohol, and forming uniform suspension after ultrasonic dispersion; soaking the sponge block subjected to the step S3 into the suspension, taking out, and then putting into a constant-temperature drying oven for drying to obtain a composite conductive sponge;
s5: and uniformly coating conductive silver paste on two sides of the composite conductive sponge, attaching conductive copper foils on two sides, and leading copper wires out of the copper foils on two sides.
Preferably, in step S1, the sponge has a thickness of 10mm, and the sponge block is not 20mm long and 15mm wide.
Preferably, the ultrasonic cleaning is performed for 15min in step S1.
Preferably, the CNT solution in step S2 is 0.5wt.%, m CNT :m CB ＝1:1。
Preferably, in step S2, magnetic stirring is performed for 15min.
Preferably, the ultrasonic dispersion is performed for 10min in step S4.
Preferably, the mass ratio of TPU powder to absolute ethanol in step S4 is 1:150.
Preferably, the drying temperature is 130 ℃ and the drying time is 30min.
Based on one general inventive concept, the embodiment of the invention provides the wearable and washable piezoresistive pressure sensor manufactured by the manufacturing method.
The embodiment of the invention also provides application of the wearable water-washable piezoresistive pressure sensor, which is manufactured by the manufacturing method or is manufactured by the wearable water-washable piezoresistive pressure sensor; applied to wet, rainy or underwater environments.
The main principle is as follows: according to the impregnation process, the CNT and the CB are attached to the skeleton of the PU sponge under the action of electrostatic force, TPU is added to serve as an adhesive for increasing the binding force between the CNT and the CB and between the CNT and the PU skeleton, TPU particles are dispersed in absolute ethyl alcohol, TPU particles are attached to the sponge skeleton under the action of electrostatic force in the impregnation mode, and the TPU particles are melted and have viscosity at 130 ℃ to enable the CNT/CB/PU to be better adhered together, and a conductive network with a permeable structure is formed, so that the CNT/CB is not easy to fall off. A schematic diagram of a specific process is shown as 4, firstly TPU particles are adhered to the surface of CNT/CB@PU after being immersed, the TPU particles are melted at 130 ℃, the melted TPU adheres the CNT, the CB and the PU, and adjacent TPU particles are connected after being melted, so that all the CNT and the CB are solidified on a PU framework.
The scheme of the invention has the following beneficial effects:
(1) According to the CNT/CB/TPU@PU sensor disclosed by the invention, as the constructed alternating conductive network of the CNT and the CB effectively improves the performance of the sensor under low pressure and higher pressure, the sensitivity and the performance of the sensor are simultaneously improved in the low pressure range and the high pressure range (the pressure is more than 2.5 KPa) of the sensor.
(2) The CNT/CB/TPU@PU sensor ingeniously utilizes the unique characteristics of PU sponge, one-dimensional CNT, zero-dimensional CB and TPU materials to form a high-efficiency sensor system. The PU sponge is based on the abundant porous structure and excellent repeated compression performance, provides a wide attachment area for the conductive material, and constructs a high-efficiency three-dimensional conductive network. This three-dimensional skeleton can produce more significant changes in electrical signals upon being deformed by pressure. The one-dimensional CNT can generate remarkable electric signal change due to its excellent conductivity and mechanical properties, especially when subjected to a large pressure, and thus is widely used in the manufacture of flexible sensors. The CB sensor constructed by the zero-dimensional material has excellent sensitivity, which is attributed to a conductive network formed by CB particles, and can be quickly reconstructed under the action of a small external force, so that more remarkable electric signal change is obtained. The CNT and the CB are combined to be used as the conductive material of the sensor, so that the sensitivity and the response performance to pressure of the sensor are greatly improved.
(3) Compared with a CNT/CB@PU sensor obtained by simple impregnation, the CNT/CB@PU sensor is damaged and difficult to recover under the action of pressure, and part of conductive materials are separated due to repeated compression, so that the stability and reliability of the sensor are affected.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a schematic illustration of the manufacturing flow of a CNT/CB/TPU@PU sensor of the invention;
fig. 2 is an SEM image of different sensors of the present invention: wherein, fig. 2 (a, d) is an SEM image of cnt@pu, fig. 2 (b, e) is an SEM image of cb@pu, and fig. 2 (e, f) is an SEM image of CNT/CB/tpu@pu;
FIG. 3 is a physical diagram of a CNT/CB/TPU@PU sensor of the invention;
FIG. 4 is a schematic diagram of the bonding CNT and CB after heating the TPU according to the present invention;
FIG. 5 is a graph of the resistance change of a sensor prepared with different concentrations of CNTs of the present invention;
FIG. 6 is a graph of the resistance change of the CNT@PU and CNT/CB@PU sensors of the invention;
FIG. 7 is a graph of the resistance change of the sensor under different conditions of the present invention; wherein FIG. 7 (a) is a graph of the resistance change of the CNT/CB/TPU@PU sensors of different proportions of TPU, and FIG. 7 (b) is a graph of the resistance change of different sensors;
FIG. 8 is a graph of the resistance response of a CNT/CB/TPU@PU sensor of the present invention after 5 water washes.
Detailed Description
In order to make the technical problems, technical solutions and advantages to be solved more apparent, the following detailed description will be given with reference to the accompanying drawings and specific embodiments.
Unless defined otherwise, all technical and scientific terms used hereinafter have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the scope of the present invention.
Unless otherwise specifically indicated, the various raw materials, reagents, instruments, equipment and the like used in the present invention are commercially available or may be prepared by existing methods.
Aiming at the existing problems, the invention provides a wearable and washable piezoresistive pressure sensor, and a preparation method and application thereof. The preparation process (shown in figure 1) of the CNT/CB/TPU@PU sensor comprises the following steps:
the PU@CNT@CB@TPU composite sponge is prepared by adopting a simple impregnation method, so that the CNT and the CB can be well attached to a sponge frame.
S1, firstly, cutting the sponge with the thickness of 10mm into square blocks with the length of 20mm and the width of 15mm by using a cutting machine. Respectively ultrasonically cleaning the sponge block in deionized water and absolute ethyl alcohol for 15min, and drying for later use. The PU sponge can be pre-compressed by compression molds with different shapes and structures, and the density of the PU sponge can be directly influenced in the preparation process; the PU sponge density can also be controlled by soaking in solution (hydrochloric acid solution and sodium hydroxide to influence the density of the PU sponge) for different time.
S2 adding appropriate amount of CB particles (m) to a CNT solution having a concentration of 0.5wt% CNT :m CB =1:1), and magnetically stirring for 15min to obtain a uniform composite solution for standby.
S3, immersing the washed sponge block into a CNT/CB solution, repeatedly squeezing for a plurality of times to enable the conductive substance to be fully attached to the sponge framework, taking out, putting into a constant temperature drying oven, drying at 130 ℃ for 30min, and taking out.
S4 dispersing the purchased TPU powder into absolute ethanol (m TPU :m ETOH And (1) carrying out ultrasonic dispersion for 10min to form a uniform suspension, immersing the prepared composite sponge into the suspension, taking out, and drying in a constant-temperature drying oven at 130 ℃ for 30min. The TPU melts at 130℃and firmly bonds the CNT, CB and PU together. A schematic diagram of a specific process is shown as 4, firstly TPU particles are adhered to the surface of CNT/CB@PU after being immersed, the TPU particles are melted at 130 ℃, the melted TPU adheres the CNT, the CB and the PU, and adjacent TPU particles are connected after being melted, so that all the CNT and the CB are solidified on a PU framework.
And S5, uniformly coating conductive silver paste on two sides of the prepared composite conductive sponge, attaching conductive copper foils on two sides, and leading copper wires out of the copper foils on two sides, wherein a physical diagram is shown in figure 3.
For comparison experiments, the same procedure was used to prepare cnt@pu with different concentrations of CNT solutions to compare the effect of CNT concentration on device performance, prepare CNT/cb@pu, compare cnt@pu with cb@pu, and also prepare CNT/cb@pu and CNT/CB/tpu@pu for comparison. Fig. 2 is an SEM image of each sensor: wherein, fig. 2 (a, d) is an SEM image of cnt@pu, fig. 2 (b, e) is an SEM image of cb@pu, fig. 2 (e, f) is an SEM image of CNT/CB/tpu@pu, and the conductive sponge is observed under different magnifications by using a scanning electron microscope, so that the three-dimensional porous structure of the sponge can be seen, and the three-dimensional skeleton provides a good adhesion surface for the conductive material. By observing the CNT@PU (figures a and d), the CB@PU (figures b and e) and the CNT/CB/TPU@PU (figures c and f) through an electron microscope, the phenomenon that the CNT on the conductive sponge framework of the CNT@PU forms a smooth and compact surface can be found, and the surface of the CB@PU sponge has the agglomeration phenomenon of the CB, so that a smooth CNT part and the agglomerated CB can be observed in the CNT/CB@PU sponge at the same time, and the uniform distribution of the CNT and the CB on the surface of the PU framework is indicated.
Example 1
Cnt@pu sensors were prepared and the effect of different concentrations of CNT solutions on the sensitivity of the device was compared (fig. 5):
step 1: firstly, cutting a sponge with the thickness of 10mm into square blocks with the length of 20mm and the width of 15mm by a cutting machine;
step 2: respectively ultrasonically cleaning the sponge blocks in deionized water and absolute ethyl alcohol for 15min, drying, and taking four blocks for later use;
step 3: respectively soaking PU sponge into 0.3wt.%,0.5wt.%,1wt.%, and 2.5wt.% CNT solution, repeatedly squeezing the sponge to ensure full soaking, taking out, drying at 130deg.C in a constant temperature drying oven, and taking out after 30min;
step 4: uniformly coating conductive silver paste on two sides of the prepared composite conductive sponge, attaching conductive copper foils on two sides, and leading copper wires out of the copper foils on two sides to obtain a sensor;
step 5: the resistance changes of sensors prepared with CNT solutions of different concentrations at the same pressure were compared.
As shown in fig. 5, the resistance response of cnt@pu sensors fabricated with different concentrations of CNTs (0.3 wt.%,0.5wt.%,1wt.%,2.5 wt.%) at the same pressure was optimal, with the greatest change in sensor resistance fabricated when the CNT concentration was 0.5wt.%, the conductivity of the sea surface was low due to the inability of the CNTs to completely cover the skeleton of the PU sponge at low concentrations, and the composite sponge conductivity was too good when the CNT concentration was too high, with reduced piezoresistive properties.
Example 2
Cnt@pu sensors, cb@pu sensors, and CNT/cb@pu sensors were prepared and the resistive responses at the same pressure were compared. (fig. 6):
step 1: firstly, cutting a sponge with the thickness of 10mm into square blocks with the length of 20mm and the width of 15mm by a cutting machine;
step 2: respectively ultrasonically cleaning the sponge blocks in deionized water and absolute ethyl alcohol for 15min, drying, and taking four blocks for later use;
step 3: the PU sponge was respectively immersed in a CNT solution having a mass concentration of 0.5wt.%, a CB solution having a mass concentration of 0.5wt.%, and CNT/CB (m CNT :m CB =1:1, 1:2) solution, repeatedly squeezing the sponge to ensure sufficient impregnation, taking out, putting into a constant temperature drying oven, drying at 130 ℃ for 30min, and taking out;
step 4: uniformly coating conductive silver paste on two sides of the prepared composite conductive sponge, attaching conductive copper foils on two sides, and leading copper wires out of the copper foils on two sides to obtain a sensor;
step 5: the resistance response at the same pressure as CNT@PU, CB@PU, CNT/CB@PU is compared.
Cb@pu sensors prepared by adding 0.5wt.% of CB solution show a larger change in resistance value at low pressure, since CB is a zero-dimensional material, the change in resistance due to contact between CB particles is larger at low pressure. Whereas CNTs are one-dimensional materials with large aspect ratios. Cnt@pu sensors prepared by adding CNT solutions with a mass concentration of 0.5wt.% exhibited a greater resistance change at high pressures. By combining the characteristics of CNT and CB, a CNT/CB@PU sensor prepared by using a CNT solution with the mass concentration of 0.5wt.% and a CB solution with the mass concentration of 0.5wt.% and a solution with the mass concentration of CNT/CB (mCNT: mCB =1:1, 1:2) is higher in resistance change than the CNT@PU sensor under the pressure of 1.7KPa (low pressure), and when the pressure is higher than 2.5KPa, the resistance change of the CNT/CB@PU sensor is higher than that of the CNT@PU and the CB@PU, which is beneficial to the fact that the alternating conductive network constructed by the CNT and the CB effectively improves the performance of the sensor under the low pressure and the higher pressure. This is because a hybrid conductive network constructed of two or more conductive fillers may overcome the weakness of a single conductive network due to a synergistic effect, unlike the sensing behavior of a conductive network containing only one conductive filler. CB rapidly forms CB-CB connections at low pressure, rapidly separates after pressure release, and the entangled CNT network is more stable at low pressure, and as pressure increases, the CNT network is broken and a large number of CNTs come into contact. Combining CNTs and CBs together to construct a hybrid CNT-CB network can effectively overcome the shortcomings of CB networks and CNT networks, thereby improving the sensing performance of the resulting sensor. (FIG. 6)
Example 3
The CNT/CB/tpu@pu sensor was prepared and the effect on the resistive response of the sensor after addition of TPU was measured (fig. 7):
step 1: firstly, cutting a sponge with the thickness of 10mm into square blocks with the length of 20mm and the width of 15mm by a cutting machine;
step 2: respectively ultrasonically cleaning the sponge blocks in deionized water and absolute ethyl alcohol for 15min, drying, and taking four blocks for later use;
step 3: the purchased TPU powder was dispersed in absolute ethanol (m TPU :m ETOH ＝1:120，m TPU :m ETOH ＝1:150，m TPU :m ETOH ＝1:200，m TPU :m ETOH Dipping the CNT/CB@PU prepared in the step 3 into the suspension, taking out, and drying in a constant temperature drying oven at 130 ℃ for 30min;
step 4: uniformly coating conductive silver paste on two sides of the prepared composite conductive sponge, attaching conductive copper foils on two sides, and leading copper wires out of the copper foils on two sides to obtain a sensor;
step 5: impact on the resistive response of the sensor after addition of TPU.
First, the effect of the amount of TPU added on the device was investigated, and FIG. 7 (a) shows that when the TPU to ethanol ratio is 1: the effect is optimal at 150, the initial resistance of the device is improved by adding proper TPU, the resistance change of the sensor under the same pressure is improved, and the conductivity of the device is reduced by excessive TPU. Fig. 7 (b) shows the change in the pressure resistance of the sensor before and after addition of the TPU, which is still good.
Example 4
The CNT/CB/tpu@pu was tested for water wash performance (fig. 8):
step 1: firstly, cutting a sponge with the thickness of 10mm into square blocks with the length of 20mm and the width of 15mm by a cutting machine;
step 2: respectively ultrasonically cleaning the sponge block in deionized water and absolute ethyl alcohol for 15min, and drying for later use
Step 3: the PU sponge is respectively immersed into the solution with the mass concentration of CNT/CB (m CNT :m CB =1:1, 1:2) solution, repeatedly squeezing the sponge to ensure sufficient impregnation, taking out, putting into a constant temperature drying oven, drying at 130 ℃ for 30min, and taking out.
Step 4: TPU powder is dispersed in absolute ethanol (m TPU :m ETOH Soaking the prepared composite sponge into the suspension, taking out, and drying in a constant-temperature drying oven at 130 ℃ for 30min;
step 5: uniformly coating conductive silver paste on two sides of the prepared composite conductive sponge, attaching conductive copper foils on two sides, and leading copper wires out of the copper foils on two sides to obtain a sensor;
step 6: adding a proper amount of water into a beaker, simulating water washing by using magnetic stirring, placing the sensor into the beaker, taking out and drying after 20 minutes of water washing each time, repeating for a plurality of times, and measuring the resistance change of the sensor under the same pressure;
step 7: the resistance response of the sensor after washing with water was compared.
From fig. 8 it can be seen that the CNT/CB/tpu@pu sensor has a 11% decrease in resistance after one water wash and thereafter remains stable. The CNT/CB@PU is stable after being washed four times, and the resistance change is reduced by 27%, so that the binding force between the CNT, the CB and the PU is enhanced after the TPU is melted at high temperature, and the sensor has good washing performance.
While the foregoing is directed to the preferred embodiments of the present invention, it will be appreciated by those skilled in the art that various modifications and adaptations can be made without departing from the principles of the present invention, and such modifications and adaptations are intended to be comprehended within the scope of the present invention.
Claims (10)
1. The preparation method of the wearable and washable piezoresistive pressure sensor is characterized by comprising the following steps of:
s1: cutting the sponge into square blocks by a cutting machine, respectively ultrasonically cleaning the sponge blocks in deionized water and absolute ethyl alcohol, and drying for later use;
s2: adding CB particles into the CNT solution, and magnetically stirring to obtain a uniform CNT/CB solution for standby;
s3: immersing the washed and dried sponge block into a CNT/CB solution, repeatedly squeezing the sponge block to ensure full immersion, taking out, and putting into a constant-temperature drying oven for drying;
s4: dispersing TPU powder into absolute ethyl alcohol, and forming uniform suspension after ultrasonic dispersion; soaking the sponge block subjected to the step S3 into the suspension, taking out, and then putting into a constant-temperature drying oven for drying to obtain a composite conductive sponge;
s5: and uniformly coating conductive silver paste on two sides of the composite conductive sponge, attaching conductive copper foils on two sides, and leading copper wires out of the copper foils on two sides.
2. The method of manufacturing a wearable and washable piezoresistive pressure sensor according to claim 1, wherein in step S1, the sponge has a thickness of 10mm and the sponge block has a length of 20mm and a width of 15mm.
3. The method for manufacturing a wearable and washable piezoresistive pressure sensor according to claim 1, wherein in step S1, the ultrasonic washing is performed for 15min.
4. The method of manufacturing a wearable and washable piezoresistive pressure sensor according to claim 1, characterized in that the CNT solution in step S2 is 0.5wt.%, m CNT :m CB ＝1:1。
5. The method for manufacturing the wearable and washable piezoresistive pressure sensor according to claim 1, wherein in step S2, the magnetic stirring is performed for 15min.
6. The method of claim 1, wherein the step S4 is performed for 10min of ultrasonic dispersion.
7. The method of manufacturing a wearable and washable piezoresistive pressure sensor according to claim 1, characterized in that the mass ratio of TPU powder to absolute ethanol in step S4 is 1:150.
8. The method for manufacturing the wearable and washable piezoresistive pressure sensor according to claim 1, wherein the drying temperature is 130 ℃ and the drying time is 30min.
9. A wearable water washable piezoresistive pressure sensor made by the method of any of claims 1-8.
10. Use of a wearable water washable piezoresistive pressure sensor according to any of the claims 1-8 or 9; applied to wet, rainy or underwater environments.
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