A bionic tactile sensor, a preparation method thereof and an application thereof

Abstract

The present invention provides a bionic tactile sensor, which includes a PDA / MXene / STA fiber electrode layer, a fiber interlayer with inner holes, and a hierarchical through-hole ionic gel electrolyte layer. The PDA / MXene / STA fiber electrode layer includes an upper PDA / MXene / STA fiber electrode layer and a lower PDA / MXene / STA fiber electrode layer. The fiber interlayer with inner holes and the hierarchical through-hole ionic gel electrolyte layer are disposed between the upper PDA / MXene / STA fiber electrode layer and the lower PDA / MXene / STA fiber electrode layer. The bionic tactile sensor of the present invention has high sensitivity. Not only does it have excellent air permeability and moisture permeability based on the fiber substrate material, providing comfort for long-term wearing, but it also has excellent hydrophobicity and self-cleaning properties, which can avoid the interference of external liquids or dust to maintain high sensing performance and long service life.

Description

Technical Field

[0001] The present invention belongs to the technical field of sensors, and in particular relates to a bionic tactile sensor, a preparation method thereof, and an application thereof. Background Art

[0002] Flexible tactile sensors have become key components for wearable devices to communicate with the external environment or the human body. In order to endow the sensors with excellent performance, many researchers have conducted a large number of studies on material preparation and selection. Compared with the past, although various practical sensing applications of flexible tactile sensors when worn on different parts of the human body have been gradually improved, the comfort of skin-attached wear for long-term continuous operation and protecting the sensor device from the influence of sweat secreted inside the skin and external water splashes, and even working in an underwater environment are still challenges. Summary of the Invention

[0003] In view of this, the present invention provides a bionic tactile sensor, a preparation method thereof, and an application thereof. The sensor is prepared from three aspects: structural design, material selection, and process preparation. The electrode material of the sensor uses non-woven fabric fibers with good flexibility as the substrate, integrated with polydopamine PDA with surface hydrophilic modification, high-conductive two-dimensional nanoconductive material MXene, and superhydrophobic stearic acid STA; the electrolyte material uses an ionic liquid mixed solution containing rich anions and cations and high stability; the fiber interlayer uses low-density non-woven fabric fibers. The preparation process of the sensor ensures that the sensor has a large number of micropores and microchannels, effectively improving the comfort of long-term wear and preventing dust pollution and liquid intrusion.

[0004] To achieve the above object, the technical solution of the present invention is realized as follows:

[0005] A bionic tactile sensor includes a PDA / MXene / STA fiber electrode layer, a fiber interlayer with inner holes, and a hierarchical through-hole ionic gel electrolyte layer. The PDA / MXene / STA fiber electrode layer includes an upper PDA / MXene / STA fiber electrode layer and a lower PDA / MXene / STA fiber electrode layer. The fiber interlayer with inner holes and the hierarchical through-hole ionic gel electrolyte layer are arranged between the upper PDA / MXene / STA fiber electrode layer and the lower PDA / MXene / STA fiber electrode layer. Among them, the fiber interlayer with inner holes is arranged below the upper PDA / MXene / STA fiber electrode layer, and the hierarchical through-hole ionic gel electrolyte layer is arranged above the lower PDA / MXene / STA fiber electrode layer.

[0006] Furthermore, the PDA / MXene / STA fiber electrode layer is integrated with non-woven fabric fibers as the substrate, polydopamine PDA with surface hydrophilic modification, two-dimensional MXene with high electrical conductivity, and superhydrophobic stearic acid STA.

[0007] Furthermore, the hierarchical through-hole ionic gel electrolyte layer is formed by using a mixed solution of ionic liquid containing rich cations and anions and high stability, and it has a through-hole microstructure with different hierarchical heights.

[0008] Furthermore, the fiber interlayer with inner holes is a low-density non-woven fabric fiber interlayer, and it has rectangular holes inside.

[0009] The present invention also provides a preparation method of a bionic tactile sensor, including the following steps:

[0010] (1) Prepare the PDA / MXene / STA fiber electrode layer;

[0011] Place the non-woven fabric fibers in a polydopamine solution for surface hydrophilic treatment, then add two-dimensional MXene with high electrical conductivity, and then spray a superhydrophobic stearic acid STA solution on the surface of the PDA / MXene fibers;

[0012] (2) Prepare the hierarchical through-hole ionic gel electrolyte layer;

[0013] It is obtained by coating a mixed solution containing ionic liquid on the surface of sandpaper and then peeling it off through a drying process;

[0014] (3) Prepare the fiber interlayer with inner holes;

[0015] Use a laser cutter to cut the non-woven fabric fibers into fiber units with rectangular holes;

[0016] (4) Install the upper PDA / MXene / STA fiber electrode layer, the fiber interlayer with inner holes, the hierarchical through-hole ionic gel electrolyte layer, and the lower PDA / MXene / STA fiber electrode layer in sequence from top to bottom, coat a semi-cured PDMS solution around the edges of each part for encapsulation, and finally dry the manufactured sensor.

[0017] The present invention also provides an application of the bionic tactile sensor. The bionic tactile sensor is applied in wearable devices. It can not only sense various physiological signals and joint movements when worn on different parts of the human body under normal open-air conditions, but also be worn in a special underwater environment for sensing applications.

[0018] Compared with the prior art, the bionic tactile sensor, preparation method and application thereof according to the present invention have the following advantages: The bionic tactile sensor of the present invention has high sensitivity. Not only does the fiber base material have excellent air permeability and moisture permeability, providing comfort for long-term wearing. At the same time, the excellent hydrophobic property and self-cleaning property can avoid the interference of external liquids or dust, so as to maintain high sensing performance and long service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0020] Figure 1 Schematic diagram for the preparation of the PDA / MXene / STA fiber electrode layer in the embodiment of the present invention;

[0021] Figure 2 Schematic diagram for the preparation process of the hierarchical through-hole ion gel electrolyte layer in the embodiment of the present invention;

[0022] Figure 3 Schematic diagram of the structure of the bionic tactile sensor in the embodiment of the present invention;

[0023] Figure 4 Schematic diagram of the working principle of the bionic tactile sensor in the embodiment of the present invention;

[0024] Figure 5 Schematic diagram of the flexibility display of the bionic tactile sensor in the embodiment of the present invention;

[0025] Figure 6 Schematic diagram of the air permeability display of the bionic tactile sensor in the embodiment of the present invention;

[0026] Figure 7 Schematic diagram of the hydrophobicity display of the bionic tactile sensor in the embodiment of the present invention;

[0027] Figure 8 Schematic diagram of the self-cleaning property display of the bionic tactile sensor in the embodiment of the present invention;

[0028] Figure 9 Schematic diagram of the washability display of the bionic tactile sensor in the embodiment of the present invention;

[0029] Figure 10 Electron micrograph of the bionic tactile sensor in the embodiment of the present invention;

[0030] Figure 11 Schematic diagram of the performance test of the bionic tactile sensor in the embodiment of the present invention;

[0031] Figure 12 Schematic diagram of the application of the bionic tactile sensor in the embodiments of the present invention.

[0032] Description of the reference numerals

[0033] 1 - Upper PDA / MXene / STA fiber electrode layer; 2 - Fiber interlayer with inner holes; 3 - Hierarchical through-hole ionic gel electrolyte layer; 4 - Lower PDA / MXene / STA fiber electrode layer; 5 - MXene nanosheet layer; 6 - STA microplate layer. Detailed implementation manners

[0034] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments may be combined with each other.

[0035] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation to the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "plurality" is two or more.

[0036] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "mounted", "connected", "connected" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood through specific situations.

[0037] The present invention will be described in detail below with reference to the drawings and in combination with the embodiments.

[0038] As Figure 3As shown in the figure, the present invention provides a bionic tactile sensor, which includes a PDA / MXene / STA fiber electrode layer, a fiber interlayer 2 with inner holes, and a hierarchical through-hole ionic gel electrolyte layer 3. The PDA / MXene / STA fiber electrode layer includes an upper PDA / MXene / STA fiber electrode layer 1 and a lower PDA / MXene / STA fiber electrode layer 4. The fiber interlayer 2 with inner holes and the hierarchical through-hole ionic gel electrolyte layer 3 are arranged between the upper PDA / MXene / STA fiber electrode layer 1 and the lower PDA / MXene / STA fiber electrode layer 4. Among them, the fiber interlayer 2 with inner holes is arranged below the upper PDA / MXene / STA fiber electrode layer 1, and the hierarchical through-hole ionic gel electrolyte layer 3 is arranged above the lower PDA / MXene / STA fiber electrode layer 4.

[0039] Specifically, for the PDA / MXene / STA fiber electrode layer, non-woven fabric fibers with good flexibility are placed in a polydopamine solution for surface hydrophilic treatment, and then highly conductive MXene with a large number of two-dimensional micro-nano sheet layer structures is added. This not only retains its inherent fiber structure but also endows it with excellent electrical conductivity and micro-nano structure. Subsequently, a stearic acid STA solution with hydrophobic properties is sprayed on the surface of the PDA / MXene fiber, which can not only prevent the oxidation of the highly conductive two-dimensional nano-conductive material MXene but also ensure that the sensor has excellent hydrophobic properties.

[0040] Specifically, the hierarchical through-hole ionic gel electrolyte layer is obtained by coating a mixed solution containing ionic liquid on the surface of sandpaper and then peeling it off through a drying process. This process can ensure that the electrolyte has a through-hole breathable microstructure with different hierarchical heights, effectively increasing the contact area between the electrode and the electrolyte, thereby improving the sensitivity and resilience of the sensor.

[0041] Specifically, the fiber interlayer with inner holes is a low-density non-woven fabric fiber interlayer, and it has rectangular holes inside.

[0042] The preparation process of a bionic tactile sensor of the present invention is as Figure 1 、 Figure 2 shown.

[0043] Example 1:

[0044] (1) Preparation of PDA / MXene / STA fiber electrode layer: Tris-HCl, 4-(2-Aminoethyl)benzene-1,2-diol (DA) and deionized water were added to a beaker in a weight ratio of 1:1.7:834, and the mixture was stirred in a magnetic stirrer water bath at 25 °C for 5 minutes. Then, the non-woven fabric fibers were fully immersed in the solution for 4 - 6 hours, taken out, rinsed repeatedly with deionized water, and then dried in an oven at 60 °C for 30 minutes to obtain PDA fibers. The prepared PDA fibers were completely immersed in a 5 mg mL -1 MXene solution, taken out and dried in an oven at 60 °C for 30 minutes to obtain PDA / MXene fibers. Then, stearic acid (STA) and hot water were added to a beaker in a weight ratio of 1:250, and the mixture was stirred in a magnetic stirrer water bath at 75 °C and 1500 rpm for 1 hour to obtain a stearic acid solution. The newly prepared stearic acid solution was sprayed onto the surface of the PDA / MXene fibers, and then dried in an oven at 75 °C for 30 minutes to finally obtain the PDA / MXene / STA fiber electrode layer;

[0045] (2) Preparation of hierarchical through-hole ion gel electrolyte layer: [EMIM][TFSI], P(VDF-HFP) and DMF were added to a beaker in a weight ratio of 1:1:10, and the mouth of the beaker was sealed with plastic wrap to prevent possible evaporation and material exchange with the outside. Then, the mixture solution was stirred in a magnetic stirrer water bath at 80 °C for 2 hours until the solution became transparent, indicating that the polymer particles were completely dissolved. The mixture solution was poured onto the surface of sandpaper and dried in an oven at 60 °C for 3 hours. Finally, the cured ion gel film was peeled off from the sandpaper to obtain the hierarchical breathable through-hole ion gel electrolyte;

[0046] (3) Preparation of fiber interlayer with inner holes: The non-woven fabric fibers were cut into fiber units with rectangular holes using a laser cutter;

[0047] (4) The prepolymer and cross-linking agent were added to a paper cup in a weight ratio of 10:1 and stirred well, and then placed on a heating table at 60 - 100 °C to obtain a semi-cured PDMS solution. Then, the upper PDA / MXene / STA fiber electrode layer, the fiber interlayer with inner holes, the hierarchical through-hole ion gel electrolyte layer, and the lower PDA / MXene / STA fiber electrode layer were installed from top to bottom in sequence, and the PDMS solution was coated around the edges of each part for encapsulation. Finally, the fabricated sensor was dried in an oven at 80 °C for 2 hours.

[0048] Example 2:

[0049] (1) Preparation of PDA / MXene / STA fiber electrode layer: Tris-HCl, 4-(2-Aminoethyl)benzene-1,2-diol (DA) and deionized water were added to a beaker in a weight ratio of 1:1.7:834, and the mixture was stirred in a magnetic stirrer water bath at 25 °C for 5 minutes. Then, the non-woven fabric fibers were fully immersed in the solution for 4 - 6 hours, taken out, rinsed repeatedly with deionized water, and then dried in an oven at 60 °C for 30 minutes to obtain PDA fibers. The prepared PDA fibers were completely immersed in 5 mg mL -1 MXene solution, taken out and dried in an oven at 60 °C for 30 minutes to obtain PDA / MXene fibers. Then, stearic acid (STA) and hot water were added to a beaker in a weight ratio of 1:250, and the mixture was stirred in a magnetic stirrer water bath at 75 °C and 1500 rpm for 1 hour to obtain a stearic acid solution. The newly prepared stearic acid solution was sprayed onto the surface of the PDA / MXene fibers, and then dried in an oven at 75 °C for 30 minutes to finally obtain the PDA / MXene / STA fiber electrode layer;

[0050] (2) Preparation of hierarchical through-hole ion gel electrolyte layer: [EMIM][TFSI], P(VDF-HFP) and DMF were added to a beaker in a weight ratio of 2:1:10, and the mouth of the beaker was sealed with plastic wrap to prevent possible evaporation and material exchange with the outside. Then, the mixture solution was stirred in a magnetic stirrer water bath at 80 °C for 2 hours until the solution became transparent, indicating that the polymer particles were completely dissolved. The mixture solution was poured onto the surface of sandpaper and dried in an oven at 60 °C for 3 hours. Finally, the cured ion gel film was peeled off from the sandpaper to obtain a hierarchical breathable through-hole ion gel electrolyte;

[0051] (3) Preparation of fiber interlayer with inner holes: The non-woven fabric fibers were cut into fiber units with rectangular holes using a laser cutter;

[0052] (4) The prepolymer and cross-linking agent were added to a paper cup in a weight ratio of 10:1 and stirred thoroughly, and then placed on a heating table at 60 - 100 °C to obtain a semi-cured PDMS solution. Then, the upper PDA / MXene / STA fiber electrode layer, the fiber interlayer with inner holes, the hierarchical through-hole ion gel electrolyte layer, and the lower PDA / MXene / STA fiber electrode layer were installed from top to bottom in sequence. The PDMS solution was coated around the edges of each part for encapsulation. Finally, the fabricated sensor was dried in an oven at 80 °C for 2 hours.

[0053] Example 3:

[0054] (1) Preparation of PDA / MXene / STA fiber electrode layer: Tris-HCl, 4-(2-Aminoethyl)benzene-1,2-diol (DA) and deionized water were added to a beaker at a weight ratio of 1:1.7:834, and stirred in a water bath with a magnetic stirrer at 25°C for 5 minutes. The non-woven fabric fiber was then fully immersed in the solution for 4-6 hours. After being taken out, it was repeatedly rinsed with deionized water and then dried in an oven at 60°C for 30 minutes to obtain PDA fiber. The prepared PDA fiber was completely immersed in 5 mg mL -1 MXene solution, take it out and place it in an oven at 60°C to dry for 30 minutes to obtain PDA / MXene fiber, then add stearic acid (STA) and hot water into a beaker at a weight ratio of 1:250, place it in a water bath with a magnetic stirrer at 75°C and stir for 1 hour to obtain a stearic acid solution, spray the newly prepared stearic acid solution onto the surface of the PDA / MXene fiber, and then dry it in an oven at 75°C for 30 minutes to finally obtain a PDA / MXene / STA fiber electrode layer;

[0055] (2) Preparation of graded through-pore ion gel electrolyte layer: [EMIM][TFSI], P(VDF-HFP) and DMF were added into a beaker in a weight ratio of 3:1:10, and the mouth of the beaker was sealed with plastic wrap to prevent possible evaporation and exchange of materials with the outside. The mixture solution was then stirred in a water bath with a magnetic stirrer at 80°C for 2 hours until the solution became transparent, indicating that the polymer particles were completely dissolved. The mixture solution was poured onto a sandpaper surface and dried in an oven at 60°C for 3 hours. Finally, the solidified ion gel film was peeled off from the sandpaper to obtain a graded air-permeable through-pore ion gel electrolyte.

[0056] (3) Preparation of fiber interlayer with inner holes: Using a laser cutting machine to cut non-woven fabric fibers into fiber units with rectangular holes;

[0057] (4) The prepolymer and the cross-linking agent were added to a paper cup in a weight ratio of 10:1 and stirred thoroughly. The paper cup was then placed on a heating table at 60-100°C to obtain a semi-cured PDMS solution. The upper PDA / MXene / STA fiber electrode layer, the fiber interlayer with inner holes, the graded through-hole ion gel electrolyte layer, and the lower PDA / MXene / STA fiber electrode layer were then installed from top to bottom. The PDMS solution was coated around the edges of each part for encapsulation. Finally, the fabricated sensor was dried in an oven at 80°C for 2 hours.

[0058] The amount of IL in the graded through-hole ion gel electrolyte layer is different, and sensors with different sensitivities are obtained as shown in Table 1.

[0059] Table 1

[0060]

[0061] Comparative Example 1:

[0062] In this example, the preparation process of "pouring the mixture solution on the surface of sandpaper and drying it in an oven at 60°C for 3 hours" in step 2 was replaced with "pouring the mixed solution into a petri dish and drying it in an oven at 60°C for 3 hours". The obtained ion gel electrolyte layer after peeling was a planar film without microstructure. Other conditions were the same as those in Example 3. With or without microstructure of the ion gel electrolyte layer, sensors with different sensitivities were obtained as shown in Table 2.

[0063] Table 2

[0064]

[0065] Comparative Example 2:

[0066] In this example, the aspect ratio of the length and width of the middle hole of the fiber interlayer in step 3 was 7:4 or 7:5 or 10:7 or 12:7. Other conditions were the same as those in Example 3. Sensors with different sensitivities were obtained as shown in Table 3.

[0067] Table 3

[0068]

[0069] Through Comparative Example 1 and Comparative Example 2, it is shown that the design of the hierarchical through-hole microstructure of the ion gel electrolyte layer can improve the performance of the sensor (such as sensitivity, detection range); the fiber interlayer with inner holes can keep the electrode and the electrolyte completely separated without pressure load, thus obtaining a small initial capacitance. As the size of the internal pore diameter increases, the performance of the sensor (such as sensitivity, detection range) gradually improves, but when the pore diameter size increases to the maximum, the sensing performance of the sensor begins to decline, and the gap with the sensing performance of the sensor without the fiber interlayer is very small, indicating that the optimal internal pore diameter size of the fiber interlayer is 10:7.

[0070] The working principle of the bionic tactile sensor of the present invention is as Figure 4 shown. When pressure is applied to the sensor, the PDA / MXene / STA fiber electrode layer, the fiber interlayer with inner holes, and the hierarchical through-hole ion gel electrolyte layer of the sensor will all deform under the action of the pressure, resulting in an increase in the contact area between the electrolyte layer and the electrode and a decrease in the distance, causing an increase in capacitance; when the pressure disappears, the PDA / MXene / STA fiber electrode layer, the fiber interlayer with inner holes, and the hierarchical through-hole ion gel electrolyte layer will return to their original states, and the capacitance will also return to its original value. The change in capacitance can be converted into an electrical signal and transmitted to the subsequent processing circuit, thereby monitoring the magnitude of the force.

[0071] The PDA / MXene / STA fiber electrode forms an electrode or electrolyte interface with the hierarchical through-hole ionic gel electrolyte layer. When the electrode layer contacts the electrolyte layer, under the action of an external power source, the internal surface charges of the electrode will adsorb ions from the electrolyte. These ions form an interfacial layer with the same charge quantity as the inner surface charge of the electrode and the opposite sign on both sides of the electrolyte interface. Due to the potential difference existing at the electrode or electrolyte interface, the two layers of charges cannot cross the boundary and neutralize each other, thus forming a supercapacitor with a stable structure.

[0072] As Figures 5 - 9 shown is the characteristic schematic diagram of the bionic tactile sensor in the embodiment of the present invention; specifically, the sensor is flexible (can be bent and twisted, as Figure 5 shown), breathable (about 723.5 mm s -1 , more than 14 times that of the TPU film, as Figure 6 shown), hydrophobic (the contact angle between artificial sweat and the sensor is 140.7°, as Figure 7 shown), self-cleaning (rinsing the starch on the surface of the sensor with water, and it can quickly slide down with water droplets, as Figure 8 shown) and washability (the sensor can be washed repeatedly, and there is no obvious difference in its initial capacitance change and squat motion detection, as Figure 9 shown).

[0073] As Figure 10 shown is the electron micrograph of the sensor. Each layer of the sensor can be clearly seen ( Figure 10 a is the cross-sectional electron micrograph of the sensor unit). The two-dimensional nano-conductive material MXene sheet structure in the PDA / MXene / STA fiber layer can promote the sensing sensitivity ( Figure 10 b is the electron micrograph of MXene nanosheets 5). The superhydrophobic STA sheet structure in the PDA / MXene / STA fiber layer can endow the sensor with excellent hydrophobicity ( Figure 10 c is the electron micrograph of STA micro-sheets 6). The hierarchical through-hole ionic gel electrolyte layer has a breathable through-hole structure with different hierarchical heights, which can effectively improve the elasticity and sensitivity of sensing and increase the contact area between the electrode and the electrolyte ( Figure 10 d is the electron micrograph of the hierarchical through-hole ionic gel electrolyte layer).

[0074] As Figure 11 shown is the performance test schematic diagram of the bionic tactile sensor in the embodiment of the present invention. The prepared pressure sensor has good sensing performance. When the sensitivity is 0 - 6 kPa, it is 1677.79 kPa -1 , and when it is 16 - 33 kPa, it is 145.82 kPa -1 ( Figure 11a), which benefits from the structural design of the prepared fiber electrodes and the hierarchical through-hole ionic gel electrolyte; it has a fast response time of 75 ms ( Figure 11 b); it has an ultra-low detection range of 50 Pa ( Figure 11 c); it has good stability, and there is basically no error in the reciprocating experiment ( Figure 11 d).

[0075] The application schematic diagram of a bionic tactile sensor of the present invention is as shown in Figure 12 The prepared flexible, breathable, waterproof and self-cleaning bionic sensor can not only sense various physiological signals (such as chest breathing) and joint movements (such as bending the neck and bending the elbow) when worn on different parts of the human body under normal open-air conditions, but also can sense in a special underwater environment, perceiving the bending of the elbow and fingers ( Figure 12 a and Figure 12 b), sensing the signal of the sensor on the radial artery of the wrist ( Figure 12 c), sensing the movements of the knee joint and ankle joint of a swimming robot toy ( Figure 12 d and Figure 12 e). And this sensor can be used as a tool for underwater communication. For example, pre-defined information using Morse code can be used for underwater communication through a sequential combination of short-time and long-time presses ( Figure 12 f and Figure 12 g). In this way, the "SOS" signal can be simply generated underwater for emergency rescue ( Figure 12 h). In addition, the Morse codes of "UP" ( Figure 12 i) and "DOWN" ( Figure 12 j) can be effectively generated by finger pressing and transmitted to the terminal for translation to convey the intention of the diver to move up or down.

[0076] The overall sensor prepared by the present invention not only has good breathability and comfort for long-term wearing, but also has good hydrophobicity and self-cleaning performance. Breathability and comfort enable the sensor to be in long-term contact with human skin without harming the skin; hydrophobicity can ensure that other moisture such as human sweat does not enter the interior of the sensor, improving the lifespan of the sensor and the accuracy and stability of the monitored signal; the self-cleaning performance can remove impurities and other pollutants on the surface of the sensor in different ways, reducing the damage to the surface material of the sensor.

[0077] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A bionic tactile sensor, characterized in that: It includes a PDA / MXene / STA fiber electrode layer, a fiber interlayer with inner holes, and a hierarchical through-hole ionic gel electrolyte layer. The PDA / MXene / STA fiber electrode layer includes an upper PDA / MXene / STA fiber electrode layer and a lower PDA / MXene / STA fiber electrode layer. The fiber interlayer with inner holes and the hierarchical through-hole ionic gel electrolyte layer are arranged between the upper PDA / MXene / STA fiber electrode layer and the lower PDA / MXene / STA fiber electrode layer. Among them, the fiber interlayer with inner holes is arranged under the upper PDA / MXene / STA fiber electrode layer, and the hierarchical through-hole ionic gel electrolyte layer is arranged above the lower PDA / MXene / STA fiber electrode layer. The PDA / MXene / STA fiber electrode layer uses non-woven fabric fibers as the substrate and is integrated with polydopamine PDA with surface hydrophilic modification, the highly conductive two-dimensional nano-conductive material MXene, and superhydrophobic stearic acid STA.

2. The bionic tactile sensor according to claim 1, characterized in that: The hierarchical through-hole ionic gel electrolyte layer is formed by using a mixed solution of ionic liquids containing rich anions and cations and having high stability, and it has a through-hole microstructure with different hierarchical heights.

3. The bionic tactile sensor according to claim 1, wherein: The fiber interlayer with inner holes is a low-density non-woven fabric fiber interlayer, and it has rectangular holes inside.

4. A preparation method of a bionic tactile sensor, characterized in that: It includes the following steps: (1) Prepare the PDA / MXene / STA fiber electrode layer; Place the non-woven fabric fibers in a polydopamine solution for surface hydrophilic treatment, then add the highly conductive two-dimensional nano-conductive material MXene, and then spray a superhydrophobic stearic acid STA solution on the surface of the PDA / MXene fibers; (2) Prepare the hierarchical through-hole ionic gel electrolyte layer; It is obtained by coating a mixed solution containing ionic liquids on the surface of sandpaper and then peeling it off through a drying process; (3) Prepare the fiber interlayer with inner holes; Use a laser cutter to cut the non-woven fabric fibers into fiber units with rectangular holes; (4) Install the upper PDA / MXene / STA fiber electrode layer, the fiber interlayer with inner holes, the hierarchical through-hole ionic gel electrolyte layer, and the lower PDA / MXene / STA fiber electrode layer in sequence from top to bottom, coat a semi-cured PDMS solution around the edges of each part for encapsulation, and finally dry the manufactured sensor.

5. An application of the bionic tactile sensor according to claim 1, characterized in that: The bionic tactile sensor is applied to wearable devices.

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