A flexible fabric-based tactile sensor and its preparation method and application

Abstract

The present application relates to a flexible fabric-based tactile sensor and its preparation method and application, belonging to the field of sensor technology. The preparation method of the flexible fabric-based tactile sensor of the present application comprises the following steps: S1, preparing an ion gel fabric-based sensitive layer; S2, preparing a flexible fabric-based electrode layer; S3, preparing a fabric-based polymer protective layer; S4, preparing a fabric-based conductive structure layer; S5, fixing two layers of fabric-based polymer protective layers between the two layers of fabric-based conductive structure layers, fixing two layers of flexible fabric-based electrode layers between the two layers of fabric-based polymer protective layers, and fixing an ion gel fabric-based sensitive layer between the two layers of flexible fabric-based electrode layers to obtain a flexible fabric-based tactile sensor. The flexible fabric-based tactile sensor provided in the present application has excellent properties such as high sensitivity, excellent dynamic response performance, low detection limit, excellent biocompatibility, and ultra-high stability.

Description

Technical Field

[0001] The present application relates to the field of sensor technology, and in particular to a flexible fabric-based tactile sensor and a preparation method and application thereof. Background Art

[0002] Wearable electronic devices capable of tactile perception are one of the core and basic components that promote the development of human-machine interface technology and the Internet of Everything. Among them, capacitive tactile sensors have the advantages of low power consumption and simple structure, and have been widely used in portable consumer electronics based on wearable devices, medical health and other fields. The increasing diversification of application scenarios has also put forward higher requirements on the performance of sensors. In addition to the common methods of increasing the dielectric constant of materials and designing porous microstructures, there is also a practice of introducing the double electric layer generation mechanism into the manufacture of sensors.

[0003] In recent years, ion gels with microstructures / porous structures have been proposed for use in the manufacture of capacitive tactile sensors. The significant interface capacitance signal and compressible geometric structure bring excellent sensing capabilities to the device, including high sensitivity and wide working range, and good performance in tracking pressure signals generated by human activities. In addition, due to the difference in output signals between dielectric capacitance and electric double layer (EDL) capacitance, in actual design, the two can also be mixed in the same device to achieve a good effect of improving sensing performance.

[0004] Flexible substrates include two categories: flexible film substrate materials (polydimethylsiloxane PDMS, polyvinyl alcohol PVA, etc.) and flexible fabric substrate materials (cotton fiber, polyester fiber, etc.). Most flexible sensors use flexible films (polydimethylsiloxane PDMS, polyvinyl alcohol PVA, etc.) as the base material. The molecular chain conformation inside the system is adjusted to achieve the effect of deformation in accordance with pressure changes. Therefore, it can achieve good flexibility and adapt to wearable devices. However, such films have viscoelasticity and will undergo stress relaxation and creep under long-term pressure, causing the output signal of the sensor to drift and stability cannot be guaranteed. In addition, film-based sensors still have safety hazards in long-term use. In the process of long-term adhesion to the surface of human skin to detect pressure in real time, health problems may be caused by sweat accumulation and bacterial growth. Therefore, it is of great practical significance to manufacture a pressure sensor with high biocompatibility, good air permeability, high sensitivity and stable performance. Summary of the invention

[0005] In view of this, the present application provides a flexible fabric-based tactile sensor and a preparation method and application thereof. The flexible fabric-based tactile sensor has the advantages of biocompatibility, air permeability, high sensitivity and high stability, and can effectively overcome the defects of the above-mentioned prior art.

[0006] The first aspect of the present application provides a method for preparing a flexible fabric-based tactile sensor, comprising the following steps:

[0007] S1, dipping the fabric into the ion gel composite solution by an immersion method, and obtaining the ion gel fabric-based sensitive layer after drying;

[0008] S2, loading a conductive electrode material on the surface of the fabric by an impregnation method and an in-situ growth method to obtain a flexible fabric-based electrode layer;

[0009] S3, selecting a fabric-based polymer with a conductive layer on the surface to prepare a fabric-based polymer protective layer;

[0010] S4, loading conductive silver paste on the surface of the fabric by spraying to obtain a fabric-based conductive structure layer;

[0011] S5. Fix two layers of fabric-based polymer protective layers between the two layers of fabric-based conductive structure layers, fix two layers of flexible fabric-based electrode layers between the two layers of fabric-based polymer protective layers, and fix the ion gel fabric-based sensitive layer between the two layers of flexible fabric-based electrode layers to obtain a flexible fabric-based tactile sensor.

[0012] Specifically, the main body of the ion gel fabric-based sensitive layer is ion gel fabric, that is, the main body is ion gel and is attached to the non-woven fabric. The ion gel fabric-based sensitive layer is the core part of the sensor, which is responsible for detecting and converting external tactile signals.

[0013] Preferably, step S2 specifically includes the following steps:

[0014] S21, modifying the flexible non-woven fabric by polydopamine (PDA) to form a polypropylene non-woven fabric / polydopamine fabric (n-WF / PDA);

[0015] S22, loading multi-walled carbon nanotubes (MWCNTs) on the polypropylene non-woven fabric / polydopamine fabric (n-WF / PDA) to form a polypropylene non-woven fabric / polydopamine / multi-walled carbon nanotube fabric (n-WF / PDA / MWCNTs);

[0016] S23, in situ growing polypyrrole (PPy) on the polypropylene non-woven fabric / polydopamine / multi-walled carbon nanotube fabric (n-WF / PDA / MWCNTs) to form a polypropylene non-woven fabric / polydopamine / multi-walled carbon nanotube / polypyrrole electrode (n-WF / PDA / MWCNTs / PPy), thereby obtaining a flexible fabric-based electrode layer.

[0017] Specifically, the flexible fabric-based electrode layer is a fabric electrode loaded with polydopamine, multi-walled carbon nanotubes, and polypyrrole, which has extremely high conductivity and can effectively promote electron transport.

[0018] Preferably, step S21 specifically includes the following steps:

[0019] S211, dissolving 6-hydroxydopamine hydrochloride in deionized water, stirring magnetically, then adding dopamine solution and tris(hydroxymethyl)aminomethane hydrochloride, stirring magnetically, to obtain a mixed solution;

[0020] S212, dropping an acid-base regulator into the mixed solution to adjust the pH value to a specified value, to obtain a polydopamine (PDA) solution;

[0021] S213, placing a polypropylene non-woven fabric (n-WF) in the polydopamine (PDA) solution, performing magnetic stirring, washing, and drying to obtain a polypropylene non-woven fabric / polydopamine fabric (n-WF / PDA).

[0022] Preferably, in step S211, the concentration of 6-hydroxydopamine hydrochloride in the mixed solution is 2 mg / ml; or

[0023] In step S212, the pH value is adjusted to 8.3-8.7; or

[0024] In step S213, the rotation speed of the magnetic stirring is 500-700 rpm, and the time of the magnetic stirring is 4 hours.

[0025] Preferably, step S22 specifically includes the following steps:

[0026] S221, dissolving multi-walled carbon nanotubes (MWCNTs) and sodium dodecylbenzene sulfonate (SDBS) in water, and performing magnetic stirring and ultrasonic stirring to obtain a uniform dispersion;

[0027] S222, placing the polypropylene non-woven fabric / polydopamine fabric (n-WF / PDA) in the dispersion, impregnating it, and drying it to obtain the polypropylene non-woven fabric / polydopamine / multi-walled carbon nanotube fabric (n-WF / PDA / MWCNTs).

[0028] Preferably, in step S221, the concentration of multi-walled carbon nanotubes (MWCNTs) in the dispersion is 25 mg / mL, and the concentration of sodium dodecylbenzene sulfonate (SDBS) in the dispersion is 10 mg / mL; or

[0029] In step S221, the magnetic stirring time is 1-2 hours, the ultrasonic stirring time is 2 hours, and the ultrasonic mode is a cycle of ultrasonic 0.5 seconds-cooling 2.5 seconds; or

[0030] In step S222, the immersion time is 5 minutes.

[0031] Preferably, step S23 specifically includes the following steps:

[0032] S231, dissolving pyrrole in water to obtain a pyrrole aqueous solution;

[0033] S232, soaking the polypropylene non-woven fabric / polydopamine / multi-walled carbon nanotube fabric (n-WF / PDA / MWCNTs) in the pyrrole aqueous solution, then placing it in an ice water bath, adding a certain concentration of ferric chloride solution thereto at a constant rate to carry out an in-situ polymerization reaction, and after the reaction is completed, washing and drying to obtain a polypropylene non-woven fabric / polydopamine / multi-walled carbon nanotube / polypyrrole electrode (n-WF / PDA / MWCNTs / PPy), that is, a flexible fabric-based electrode layer; or

[0034] In step S231, the concentration of the pyrrole aqueous solution is 0.5M; or

[0035] In step S232, the concentration ratio of pyrrole to ferric chloride is 3:1-1:3, the dripping rate is 0.15-0.25 ml / s, and the in-situ polymerization reaction time is 2 h.

[0036] Preferably, in step S1, the ion gel composite solution is an acetone solution of polyvinylidene fluoride (PVDF) and 1-ethyl-3-methylimidazole bis(trifluoromethylsulfonyl)imide ([EMIM][TFSI]), and the mass ratio of polyvinylidene fluoride (PVDF) to 1-ethyl-3-methylimidazole bis(trifluoromethylsulfonyl)imide ([EMIM][TFSI]) is 1:1.

[0037] Specifically, the fabric-based polymer protective layer ensures flexibility on the one hand, and matches the flexible fabric-based electrode layer on the other hand. The fabric-based polymer material is selected, for example, polypropylene or corresponding flexible materials are selected. The fabric-based polymer protective layer not only has good flexibility, but also ensures good adhesion, so that the flexible fabric-based electrode layer is perfectly combined with it, protecting the sensor from external physical damage or liquid intrusion.

[0038] A second aspect of the present application further provides a flexible fabric-based tactile sensor, which is a flexible fabric-based tactile sensor manufactured using the above method.

[0039] The third aspect of the present application also provides the application of the above-mentioned flexible fabric-based tactile sensor in wearable electronic devices.

[0040] Specifically, the flexible fabric-based tactile sensor of the present application can accurately measure tiny signals of biological bodies.

[0041] Compared with the prior art, this application has the following beneficial effects:

[0042] 1. The flexible fabric-based tactile sensor prepared in this application has excellent performances such as high sensitivity, excellent dynamic response performance, low detection limit, excellent biocompatibility, and ultra-high stability. The flexible fabric-based tactile sensor reaches 2.37 kPa in the pressure range of 0-20 kPa. -1 High sensitivity and R 2 = High linearity of 0.993, when the measurement range is extended to 200kPa, the sensitivity can still be maintained at 0.64kPa -1 , with excellent dynamic response performance (fast response time as low as 44ms) and low detection limit (5Pa); the flexible fabric-based tactile sensor has excellent performance in identifying physiological activity signals such as wrist bending and oral chewing, airflow pressure changes and Morse code signals; the flexible fabric-based tactile sensor also has excellent flexibility, breathability and comfort, suitable for large-area preparation and integration with clothing, and has very broad application prospects in many fields such as electronic skin and wearable devices;

[0043] 2. This application improves the structural design of the sensor, and prepares a flexible fabric-based tactile sensor that takes into account biocompatibility, air permeability, high sensitivity, and high stability by using non-woven fabric as the base skeleton;

[0044] 3. The flexible fabric-based tactile sensor of the present application has multi-walled carbon nanotubes loaded on the surface of a polydopamine-modified fabric by an impregnation method, and polypyrrole is grown in situ as an electrode; in addition, ion gel is loaded on the surface of the fabric as an ion gel fabric-based sensitive layer; through the generation and conversion mechanism of dielectric capacitance and EDL capacitance during the contact process between the flexible fabric-based electrode layer and the ion gel fabric-based sensitive layer, a higher capacitance signal and sensitivity are brought to the sensor device, thereby achieving the purpose of improving the comprehensive performance of the sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solutions in the present application or the prior art, the drawings required for use in the description of the present application or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0046] Figure 1 This is a schematic diagram of the structure of the flexible fabric-based tactile sensor of the present application;

[0047] Figure 2 This is a schematic structural diagram of a flexible fabric-based electrode layer in a flexible fabric-based tactile sensor of the present application;

[0048] Figure 3This is a schematic diagram of the process for preparing the flexible fabric-based tactile sensor of the present application;

[0049] Figure 4 This is a schematic diagram of a process for preparing a flexible fabric-based electrode layer in a flexible fabric-based tactile sensor of the present application;

[0050] Figure 5 This is a fast response / recovery curve diagram of the flexible fabric-based tactile sensor of Example 1 of the present application;

[0051] Figure 6 This is a cyclic stability curve diagram of the flexible fabric-based tactile sensor of Example 1 of the present application.

[0052] Description of reference numerals:

[0053] 1. Flexible fabric-based tactile sensor;

[0054] 11. Ion gel fabric-based sensitive layer;

[0055] 12. Flexible fabric-based electrode layer;

[0056] 121. Polypropylene nonwoven fabric layer (n-WF); 122. Polydopamine layer (PDA); 123. Multi-walled carbon nanotube layer (MWCNTs); 124. Polypyrrole layer (PPy);

[0057] 13. Fabric-based polymer protective layer;

[0058] 14. Fabric-based conductive structural layer. DETAILED DESCRIPTION

[0059] In order to make the purpose, technical solutions and advantages of this application clearer, the technical solutions in this application will be clearly and completely described below in conjunction with the drawings in this application. Obviously, the described embodiments are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0060] It should also be noted here that in order to avoid obscuring the present application due to unnecessary details, only the structures and / or processing steps closely related to the scheme according to the present application are shown in the accompanying drawings, while other details that are not very relevant to the present application are omitted.

[0061] As used herein, the term "including" and its variations represent open terms, meaning "including but not limited to". The terms "based on", "according to", etc. mean "based at least in part on", "based at least in part on". The terms "one embodiment" and "an embodiment" mean "at least one embodiment". The term "another embodiment" means "at least one other embodiment". The terms "first", "second", etc. may refer to different or the same objects. Other definitions may be included below, whether explicit or implicit. Unless the context clearly indicates otherwise, the definition of a term is consistent throughout the specification.

[0062] Unless otherwise specified, the experimental methods used in the examples of this application are all conventional methods.

[0063] In the following examples, unless otherwise specified, all raw materials can be purchased from commercial sources or prepared by conventional methods. The fabrics in the examples of the present application are all made of polypropylene non-woven fabrics.

[0064] Example 1

[0065] like Figure 1-4 As shown, the preparation method of the double electric layer / dielectric capacitor hybrid flexible fabric-based tactile sensor of this embodiment is as follows Figure 3 As shown, the flexible fabric-based tactile sensor is mainly composed of polypropylene fabric / polydopamine / multi-walled carbon nanotubes / polypyrrole electrodes and ion gel fabric. The preparation process of the flexible fabric-based electrode layer is as follows Figure 2 and Figure 4 As shown, the structure of the prepared double electric layer / dielectric capacitor hybrid flexible fabric-based tactile sensor is as follows Figure 1 As shown, the two lines on the left represent wires.

[0066] The method for preparing the double electric layer / dielectric capacitor hybrid flexible fabric-based tactile sensor of this embodiment comprises the following steps:

[0067] S1. Cut polypropylene non-woven fabrics of different weights into 15 mm × 15 mm pieces with a laser cutting machine, wash them with acetone, ethanol and deionized water ultrasonically in turn, and dry them in an oven for 6 hours for later use; place the washed and dried non-woven square pieces in an acetone solution of polyvinylidene fluoride (PVDF) / 1-ethyl-3-methylimidazole bis(trifluoromethylsulfonyl)imide ([EMIM][TFSI]) with a mass ratio of 1:1, immerse for five minutes, take them out, place them on a clean glass slide, and put them in an oven at 40°C for 6 hours to obtain a fabric loaded with ion gel, i.e., an ion gel fabric-based sensitive layer 11;

[0068] S2, cutting polypropylene non-woven fabrics of different weights into 15 mm × 15 mm pieces of fabric using a laser cutting machine, washing them with acetone, ethanol and deionized water ultrasonically in turn, drying them in an oven for 6 hours for later use; loading conductive electrode materials on the fabric surface by an impregnation method and an in-situ growth method to obtain a flexible fabric-based electrode layer 12;

[0069] For example, considering that the surface of the non-woven fabric is hydrophobic and the subsequent loading effect is poor, the adhesion of the subsequent loaded conductive material is improved by in-situ growing polydopamine on its surface.

[0070] S21, modifying the polypropylene non-woven fabric by polydopamine (PDA) to form a polypropylene non-woven fabric / polydopamine fabric (n-WF / PDA);

[0071] Specifically, the specific steps of S21 include: weighing 2.06 g of 6-hydroxydopamine hydrochloride into a beaker, adding deionized water to a solution with a concentration of 2 mg / mL, and performing magnetic stirring; measuring 200 mL of the prepared dopamine solution, weighing a certain amount of tris(hydroxymethyl)aminomethane hydrochloride and adding it thereto, and performing magnetic stirring; preparing a NaOH solution with a concentration of 1 M, adding it dropwise to the previously prepared solution, and adjusting the pH of the solution to about 8.5; then, placing the non-woven fabric in the above solution and stirring for 4 hours, controlling the rotation speed to 600 rpm, and after the reaction is completed, washing with deionized water, placing it in an oven at 60° C. and drying it for 12 hours to obtain n-WF / PDA fabric.

[0072] S22, loading multi-walled carbon nanotubes (MWCNTs) on the polypropylene non-woven fabric / polydopamine fabric (n-WF / PDA) to form a polypropylene non-woven fabric / polydopamine / multi-walled carbon nanotube fabric (n-WF / PDA / MWCNTs);

[0073] Specifically, the specific steps of S22 include: weighing functionalized multi-walled carbon nanotubes and surfactant sodium dodecylbenzene sulfonate (SDBS) and adding them into deionized water to prepare a dispersion with a MWCNTs concentration of 25 mg / mL and a SDBS concentration of 10 mg / mL, and magnetically stirring for 1 hour for preliminary uniform dispersion; using an ultrasonic disperser to further disperse the dispersion, setting the power to 60%, the ultrasonic time to 0.5 s, the cooling time to 2.5 s, and ultrasonicating for a total of 2 hours to obtain a uniform and non-stratified carbon nanotube dispersion; after immersing the n-WF / PDA fabric in the carbon tube dispersion for 5 minutes, taking it out and placing it in an oven at 60°C for drying for 6 hours to obtain the n-WF / PDA / MWCNTs fabric.

[0074] S23, in-situ growing polypyrrole (PPy) on the polypropylene non-woven fabric / polydopamine / multi-walled carbon nanotube fabric (n-WF / PDA / MWCNTs) to form a polypropylene non-woven fabric / polydopamine / multi-walled carbon nanotube / polypyrrole electrode (n-WF / PDA / MWCNTs / PPy), thereby obtaining a flexible fabric-based electrode layer 12, wherein the flexible fabric-based electrode layer 12 includes a polypropylene non-woven fabric layer (n-WF) 121, a polydopamine layer (PDA) 122, a multi-walled carbon nanotube layer (MWCNTs) 123, and a polypyrrole layer (PPy) 124;

[0075] Specifically, the specific steps of S23 include: weighing a certain amount of pyrrole in deionized water to prepare a 0.5 M pyrrole aqueous solution; soaking the prepared n-WF / PDA / MWCNTs fabric in the pyrrole aqueous solution for 1 h to allow the pyrrole to fully contact the fabric; weighing a certain amount of ferric chloride and dissolving it in deionized water to prepare different concentrations of FeCl 3 aqueous solution; control the concentration ratio of pyrrole to ferric chloride to be 1:2, place the beaker containing the pyrrole aqueous solution in an ice water bath, and use a syringe pump to slowly drop FeCl 3 solution, controlling the dripping rate at 0.2 ml / s, reacting for 2 hours to carry out in-situ polymerization of pyrrole on the fabric; washing the obtained black fabric with deionized water several times until there is no black precipitate in the washing waste liquid; drying the fabric in an oven at 70°C to constant weight to obtain an n-WF / PDA / MWCNTs / PPy electrode, that is, a flexible fabric-based electrode layer 12; fixing the ion gel fabric-based sensitive layer 11 between the upper and lower flexible fabric-based electrode layers 12 with an adhesive material.

[0076] S3, selecting a fabric-based polymer with a conductive layer on the surface to prepare a fabric-based polymer protective layer 13;

[0077] Specifically, S3 specifically includes the following steps: cutting polypropylene non-woven fabrics of different weights into 15mm×15mm pieces of cloth with a laser cutting machine, ultrasonically washing with acetone, ethanol, and deionized water in turn, and drying in an oven for 6 hours for use; taking 10g of nano-barium titanate powder, adding it to 100mL of hydrogen peroxide solution, heating the solution for 2.5h and then centrifuging it, and the obtained precipitate is vacuum dried and dispersed in anhydrous ethanol; then, adding a 1% mass fraction of KH550 solution to the dispersion for surface treatment; The surface is silanized, and the obtained barium titanate is dispersed in n-hexane after centrifugal washing; 10g of hydroxyl-terminated silicone grease is added to the barium titanate dispersion, and then it is mixed with 10% by mass dibutyltin dilaurate tetraethyl orthosilicate solution in a volume ratio of 10:1, shaken and put into a syringe pump, the syringe pump and ultrasonic atomizer are turned on, and the high dielectric constant adhesive material is sprayed onto the washed non-woven fabric using a program-controlled XY axis displacement platform to obtain a protective layer, i.e., a fabric-based polymer protective layer 13.

[0078] S4, loading conductive silver paste on the surface of the fabric by spraying to obtain a fabric-based conductive structure layer 14;

[0079] Specifically, S4 specifically includes the following steps: cutting polypropylene non-woven fabrics of different gram weights into 15mm×15mm pieces of cloth with a laser cutting machine, ultrasonically washing with acetone, ethanol and deionized water in turn, placing the non-woven fabric in an oven to dry for 6 hours, placing the non-woven fabric in a dopamine hydrochloride solution with a concentration of 2g / L, adding 50ml of sodium borate buffer to stabilize the pH at about 8.5, stirring for 24 hours, taking out the non-woven fabric, washing the non-woven fabric with deionized water for multiple times and then drying; placing the non-woven fabric in a silver nanowire solution with a concentration of 0.1mg / mL, soaking for 15 minutes, taking out the non-woven fabric and placing it in an oven to dry, repeating this step 3 times to obtain a porous electrode with good conductivity, that is, a fabric-based conductive structure layer 14; covering the porous electrode on the surface of the fabric-based polymer protective layer 13 with a pressure of 10kPa, and curing at room temperature for 12 hours to complete the bonding of the foam porous electrode to obtain a capacitive flexible pressure-temperature integrated flexible fabric-based tactile sensor 1 with a stable structure.

[0080] Example 2

[0081] The preparation method of the double electric layer / dielectric capacitor hybrid flexible fabric-based tactile sensor provided in this embodiment can refer to Example 1, except that the pH value in step S21 is 8.3, the magnetic stirring time in step S22 is 1 hour, and the dripping acceleration in step S23 is 0.15 ml / s.

[0082] Example 3

[0083] The preparation method of the double electric layer / dielectric capacitor hybrid flexible fabric-based tactile sensor provided in this embodiment can refer to Example 1, except that the pH in step S21 is 8.7, the magnetic stirring time in step S22 is 2 hours, and the dripping acceleration in step S23 is 0.25 ml / s.

[0084] Example 4

[0085] The preparation method of the double electric layer / dielectric capacitor hybrid flexible fabric-based tactile sensor provided in this embodiment can refer to Example 1, except that in step S23, the concentration ratio of pyrrole to ferric chloride is controlled to be 2:1.

[0086] Example 5

[0087] The preparation method of the double electric layer / dielectric capacitor hybrid flexible fabric-based tactile sensor provided in this embodiment can refer to Example 1, except that the concentration ratio of pyrrole to ferric chloride is controlled to be 1:1.

[0088] Example 6

[0089] The preparation method of the double electric layer / dielectric capacitor hybrid flexible fabric-based tactile sensor provided in this embodiment can refer to Example 1, except that the concentration ratio of pyrrole to ferric chloride is controlled to be 3:1.

[0090] Example 7

[0091] The preparation method of the double electric layer / dielectric capacitor hybrid flexible fabric-based tactile sensor provided in this embodiment can refer to Example 1, except that the concentration ratio of pyrrole to ferric chloride is controlled to be 1:3.

[0092] Test example

[0093] Figure 5 The response time and recovery time of the double-electric layer / dielectric capacitor hybrid flexible fabric-based tactile sensor prepared in Example 1 are demonstrated. When a small pressure of 200Pa is applied to the sensor, the electrical signal can change rapidly. The response time is 107ms. Thanks to the excellent support and resilience of the fabric, the recovery time is only 44ms, which is close to the sensing time of human skin and can meet the requirements for sensors in application scenarios such as motion assessment and health monitoring.

[0094] Figure 6The cyclic curve of the fabric-based pressure sensor of the double-electric layer / dielectric capacitor hybrid flexible fabric-based tactile sensor prepared in Example 1 is shown. Thanks to the good supporting force and resilience of the fabric, the sensor shows ultra-high stability under repeated loading and unloading pressure. A pressure of 1 kPa is repeatedly applied to the sensor by an electric tension and compression instrument. In more than 5000 cycles, the output signal and baseline signal of the device remain basically unchanged, showing excellent repeatability and applicability for installation in equipment that needs to serve for a long time.

[0095] In summary, the flexible fabric-based tactile sensor prepared according to the method of the present application uses a simple impregnation method to prepare an ion gel fabric as an ion gel fabric-based sensitive layer on the fabric surface; through the generation and conversion mechanism of dielectric capacitance and EDL capacitance during the contact process between the electrode and the sensitive layer, the purpose of improving the comprehensive performance of the sensor is achieved. The sensor also exhibits good dynamic response performance. Since the fabric has excellent mechanical support and resilience, the sensor can show ultra-high stability and repeatability, avoiding the problem of signal drift or attenuation in sensors prepared with pure polymer electrolyte gel.

[0096] The terms "exemplary," "example," and the like used throughout this specification mean "used as an example, instance, or illustration" and do not mean "preferred" or "advantageous" over other embodiments. The detailed description includes specific details for the purpose of providing an understanding of the described techniques. However, these techniques can be implemented without these specific details. In some instances, in order to avoid obscuring the concepts of the described embodiments, well-known structures and devices are shown in block diagram form.

[0097] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

[0098] The above description of the contents of this specification is provided to enable any person of ordinary skill in the art to implement or use the contents of this specification. Various modifications to the contents of this specification will be apparent to those of ordinary skill in the art, and the general principles defined herein may be applied to other variations without departing from the scope of protection of the contents of this specification. Therefore, the contents of this specification are not limited to the examples and designs described herein, but are consistent with the widest range of principles and novel features disclosed herein.

Claims

1. A method for preparing a flexible fabric-based tactile sensor, characterized in that: The following steps are involved: S1, dipping the fabric into the ion gel composite solution by an immersion method, and obtaining the ion gel fabric-based sensitive layer after drying; S2, loading a conductive electrode material on the surface of the fabric by an impregnation method and an in-situ growth method to obtain a flexible fabric-based electrode layer; S3, selecting a fabric-based polymer with a conductive layer on the surface to prepare a fabric-based polymer protective layer; S4, loading conductive silver paste on the surface of the fabric by spraying to obtain a fabric-based conductive structure layer; S5. Fix two layers of fabric-based polymer protective layers between the two layers of fabric-based conductive structure layers, fix two layers of flexible fabric-based electrode layers between the two layers of fabric-based polymer protective layers, and fix the ion gel fabric-based sensitive layer between the two layers of flexible fabric-based electrode layers to obtain a flexible fabric-based tactile sensor.

2. The method for preparing a flexible fabric-based tactile sensor according to claim 1, characterized in that: Step S2 specifically includes the following steps: S21, modifying the flexible non-woven fabric by polydopamine to form a polypropylene non-woven fabric / polydopamine fabric; S22, loading multi-walled carbon nanotubes on the polypropylene non-woven fabric / polydopamine fabric to form a polypropylene non-woven fabric / polydopamine / multi-walled carbon nanotube fabric; S23, in-situ growing polypyrrole on the polypropylene non-woven fabric / polydopamine / multi-walled carbon nanotube fabric to form a polypropylene non-woven fabric / polydopamine / multi-walled carbon nanotube / polypyrrole electrode, thereby obtaining a flexible fabric-based electrode layer.

3. The method for preparing a flexible fabric-based tactile sensor according to claim 2, characterized in that: Step S21 specifically includes the following steps: S211, dissolving 6-hydroxydopamine hydrochloride in deionized water, stirring magnetically, then adding dopamine solution and tris(hydroxymethyl)aminomethane hydrochloride, stirring magnetically, to obtain a mixed solution; S212, dropping an acid-base regulator into the mixed solution to adjust the pH value to a specified value, to obtain a polydopamine solution; S213, placing a polypropylene non-woven fabric in the polydopamine solution, performing magnetic stirring, washing, and drying to obtain a polypropylene non-woven fabric / polydopamine fabric.

4. The method for preparing a flexible fabric-based tactile sensor according to claim 3, characterized in that: In step S211, the concentration of 6-hydroxydopamine hydrochloride in the mixed solution is 2 mg / ml; or In step S212, the pH value is adjusted to 8.3-8.7; or In step S213, the rotation speed of the magnetic stirring is 500-700 rpm, and the time of the magnetic stirring is 4 hours.

5. The method for preparing a flexible fabric-based tactile sensor according to claim 2, characterized in that: Step S22 specifically includes the following steps: S221, dissolving multi-walled carbon nanotubes and sodium dodecylbenzene sulfonate in water, and performing magnetic stirring and ultrasonic stirring to obtain a uniform dispersion; S222, placing the polypropylene non-woven fabric / polydopamine fabric in the dispersion, impregnating the fabric, and drying the fabric to obtain the polypropylene non-woven fabric / polydopamine / multi-walled carbon nanotube fabric.

6. The method for preparing a flexible fabric-based tactile sensor according to claim 5, characterized in that: In step S221, the concentration of the multi-walled carbon nanotubes in the dispersion is 25 mg / mL, and the concentration of the sodium dodecylbenzene sulfonate in the dispersion is 10 mg / mL; or In step S221, the magnetic stirring time is 1-2 hours, the ultrasonic stirring time is 2 hours, and the ultrasonic mode is a cycle of ultrasonic 0.5 seconds-cooling 2.5 seconds; or In step S222, the immersion time is 5 minutes.

7. The method for preparing a flexible fabric-based tactile sensor according to claim 1, characterized in that: Step S23 specifically includes the following steps: S231, dissolving pyrrole in water to obtain a pyrrole aqueous solution; S232, soaking the polypropylene non-woven fabric / polydopamine / multi-walled carbon nanotube fabric in the pyrrole aqueous solution, then placing it in an ice water bath, adding a certain concentration of ferric chloride solution thereto at a constant rate to carry out an in-situ polymerization reaction, and after the reaction is completed, washing and drying to obtain a polypropylene non-woven fabric / polydopamine / multi-walled carbon nanotube / polypyrrole electrode, that is, a flexible fabric-based electrode layer; or In step S231, the concentration of the pyrrole aqueous solution is 0.5M; or In step S232, the concentration ratio of pyrrole to ferric chloride is 3:1-1:3, the dripping rate is 0.15-0.25 ml / s, and the in-situ polymerization reaction time is 2 h.

8. The method for preparing a flexible fabric-based tactile sensor according to claim 1, characterized in that: In step S1, the ion gel composite solution is an acetone solution of polyvinylidene fluoride and 1-ethyl-3-methylimidazole bis(trifluoromethylsulfonyl)imide, and the mass ratio of polyvinylidene fluoride to 1-ethyl-3-methylimidazole bis(trifluoromethylsulfonyl)imide is 1:

1.

9. A flexible fabric-based tactile sensor, characterized in that: A flexible fabric-based tactile sensor made by the method described in any one of claims 1 to 8.

10. Application of the flexible fabric-based tactile sensor according to claim 9 in wearable electronic devices.

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