An antibacterial, breathable, hydrophobic, self-cleaning type bionic fiber tactile sensor and a preparation method and application thereof

Abstract

The application provides an antibacterial, breathable, hydrophobic and self-cleaning biomimetic fiber tactile sensor and a preparation method and application thereof. The biomimetic fiber tactile sensor comprises a ZIF-67 / Ag NWs / STA fiber electrode layer and an IL / PVDF electrolyte layer. The ZIF-67 / Ag NWs / STA fiber electrode layer takes a fiber as a substrate, is loaded with ZIF-67, is coated with Ag NWs on both sides, and is hydrophobically modified on one side by STA to obtain the ZIF-67 / Ag NWs / STA fiber electrode layer. The IL / PVDF electrolyte layer is loaded with ions, one side is a through-hole and convex combined microstructure, and the other side is an imitation octopus sucker structure. The ZIF-67 / Ag NWs / STA fiber electrode layer has two, which are attached to the two sides of the IL / PVDF electrolyte layer, and the side of the ZIF-67 / Ag NWs / STA fiber electrode layer without hydrophobic modification faces the IL / PVDF electrolyte layer. The biomimetic fiber tactile sensor has superhydrophobicity, can resist the penetration of a solution, has self-cleaning property, reduces the damage to the surface material of the sensor, has breathability, allows the transmission of air / moisture, has antibacterial property, maintains the balance of the skin system, and has good sensitivity and detection range.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of flexible sensors, and particularly relates to an antibacterial, breathable, hydrophobic and self-cleaning bionic fiber tactile sensor and a preparation method and application thereof. BACKGROUND

[0002] The rapid development of information technology and the Internet of Things increases the demand for intelligent sensing devices. Flexible sensors similar to human skin are widely used due to their ability to interact with the environment, cooperate with robots and monitor health. However, most reported sensors are based on solid or impermeable polymer substrates, which can cause skin itching, inflammation and other problems when worn for a long time, seriously affecting the wearing comfort. In addition, non-biocompatible materials and residual toxic chemicals in the sensor can cause serious damage to the skin during long-term use. Therefore, it is urgent to prepare a flexible sensor with breathability and biocompatibility to meet the strict requirements of human motion detection and implantable electronic devices. Fiber-based tactile sensors have good breathability and are easy to integrate with smart clothing. However, the fiber substrate has natural water absorption, which makes the designed sensor susceptible to sweat or water after long-term wear. Therefore, it is urgent to develop a hydrophobic sensor, which is crucial for extending its service life and expanding its application range. Therefore, a sensor based on a fiber structure with antibacterial, breathable and hydrophobic properties is developed, which is crucial for obtaining human comfortable wearable motion detection. SUMMARY

[0003] Therefore, in order to solve the above technical problems, the application provides an antibacterial, breathable, hydrophobic and self-cleaning bionic fiber tactile sensor, and also provides a preparation method and application thereof. The electrode layer is obtained by integrating a fiber as a substrate with ZIF-67 having a highly stable structure, Ag NWs having high conductivity and antibacterial properties, and superhydrophobic stearic acid STA. The electrolyte layer with different microstructures on both sides is obtained by using an ionic liquid mixed solution containing rich anions and cations and having high stability, wherein one side is a through-hole and protrusion combined microstructure, and the other side is an imitation octopus sucker structure. The bionic fiber tactile sensor has superhydrophobicity, can resist the penetration of the solution, has self-cleaning property, reduces damage to the surface material of the sensor, has good breathability, allows air / water transmission, has antibacterial property, maintains the balance of the skin system, and has good sensitivity and detection range.

[0004] To achieve the above purpose, the technical scheme of the application is as follows:

[0005] In one aspect, the application provides an antibacterial, breathable, hydrophobic and self-cleaning bionic fiber tactile sensor, comprising:

[0006] ZIF-67 / Ag NWs / STA fiber electrode layer, which is based on a fiber, loaded with ZIF-67, coated with Ag NWs on both sides, and then modified with STA on one side to obtain hydrophobicity;

[0007] IL / PVDF electrolyte layer, which is loaded with ions, and has a through-hole and convex combined microstructure on one side and an imitation octopus sucker structure on the other side;

[0008] The ZIF-67 / Ag NWs / STA fiber electrode layer has two, respectively attached to the two sides of the IL / PVDF electrolyte layer, and the side of the ZIF-67 / Ag NWs / STA fiber electrode layer that is not modified towards the IL / PVDF electrolyte layer.

[0009] In some preferred embodiments of the biomimetic fiber tactile sensor of the present application, the ZIF-67 / Ag NWs / STA fiber electrode layer is prepared by loading ZIF-67 on a fiber in a mixed solution of 2-methylimidazole, cobalt nitrate hexahydrate and methanol by in-situ growth method, coating Ag NWs solution on both sides, drying, and then spraying a hydrophobic STA solution on one side, drying to obtain.

[0010] In some preferred embodiments of the biomimetic fiber tactile sensor of the present application, the molar ratio of 2-methylimidazole to cobalt nitrate hexahydrate in the mixed solution of 2-methylimidazole, cobalt nitrate hexahydrate and methanol is 2-3:5-15, and the molar concentration of 2-methylimidazole in methanol is 0.25-1 mol / l.

[0011] In some preferred embodiments of the biomimetic fiber tactile sensor of the present application, the concentration of the Ag NWs solution is 4-7 mg / mL

[0012] In some preferred embodiments of the biomimetic fiber tactile sensor of the present application, the mass ratio of STA to water in the hydrophobic STA solution is 1:100-125.

[0013] In some preferred embodiments of the biomimetic fiber tactile sensor of the present application, the IL / PVDF electrolyte layer is obtained by coating a mixed solution containing an ionic liquid on a sandpaper provided with a plurality of circular holes, drying and then peeling off.

[0014] In some preferred embodiments of the biomimetic fiber tactile sensor of the present application, the mass ratio of [EMIM][TFSI], P(VDF-HFP) and DMF in the mixed solution containing an ionic liquid is 5-28:7-8.5:65-85.

[0015] In some preferred embodiments of the biomimetic fiber tactile sensor of the present application, the diameter of the circular hole is 3-4 mm.

[0016] Another aspect of the present application provides a method for preparing an antibacterial, breathable, hydrophobic, self-cleaning biomimetic fiber tactile sensor, comprising the following steps:

[0017] S1, preparing a ZIF-67 / Ag NWs / STA fiber electrode layer

[0018] The fiber is placed in a mixed solution of 2-methylimidazole, cobalt nitrate hexahydrate and methanol, and ZIF-67 is loaded onto the fiber by in-situ growth method to obtain a ZIF-67 fiber; Ag NWs solution is coated on both surfaces of the ZIF-67 fiber, and after drying, a ZIF-67 / Ag NWs fiber is obtained; stearic acid solution is sprayed on one surface of the ZIF-67 / Ag NWs fiber, and after drying, the ZIF-67 / Ag NWs / STA fiber electrode layer is obtained;

[0019] S2, preparing an IL / PVDF electrolyte layer

[0020] A plurality of circular holes are cut out on the sandpaper, and then a mixed solution containing an ionic liquid is coated on the surface of the sandpaper, and after drying, the IL / PVDF electrolyte layer is obtained by peeling off;

[0021] S3, IL / PVDF solution is applied as glue on both surfaces of the IL / PVDF electrolyte layer prepared in S2, and then the ZIF-67 / Ag NWs / STA fiber electrode layer prepared in S1 is adhered to both surfaces of the IL / PVDF electrolyte layer, respectively, and after drying, the biomimetic fiber tactile sensor is obtained; wherein the non-hydrophobic modified surface of the ZIF-67 / Ag NWs / STA fiber electrode layer faces the IL / PVDF electrolyte layer.

[0022] The ZIF-67 / Ag NWs / STA fiber electrode layer is prepared by placing a fiber with good flexibility in a mixed solution of 2-methylimidazole, cobalt nitrate hexahydrate and methanol, and loading ZIF-67 onto the fiber by in-situ growth method, which not only retains its inherent fiber structure, but also endows it with excellent antibacterial performance and micro-nano structure. Then, Ag NWs solution with high conductivity and antibacterial performance is coated on the ZIF-67 fiber, so that the fiber forms a conductive path, and the vertical and horizontal Ag NWs help to reduce the initial contact area between the electrode and the electrolyte layer, thereby increasing the performance (such as sensitivity and detection range) of the sensor, while further increasing the antibacterial performance. Then, stearic acid STA with hydrophobic performance is sprayed to improve the hydrophobicity and self-cleaning performance of the sensor;

[0023] The IL / PVDF electrolyte layer is obtained by coating a mixed solution containing an ionic liquid on the surface of sandpaper treated by a laser cutting machine and then peeling off after drying, which can not only ensure that one side of the electrolyte has a through-hole structure with different levels of height, but also has an octopus sucker structure on the other side, effectively reducing the initial contact area between the electrode and the electrolyte, thereby improving the sensitivity and resilience of the sensor.

[0024] In some preferred embodiments of the method for preparing the biomimetic fiber tactile sensor, in S1, the molar ratio of 2-methylimidazole to cobalt nitrate hexahydrate in the mixed solution is 2-3:5-15, and the molar concentration of 2-methylimidazole in methanol is 0.25-1 mol / l; the concentration of the Ag NWs solution is 4-7 mg / mL; and the mass ratio of STA to water in the stearic acid solution is 1:100-125.

[0025] In some preferred embodiments of the method for preparing the biomimetic fiber tactile sensor, in S2, the mass ratio of [EMIM][TFSI], P(VDF-HFP) and DMF in the mixed solution containing an ionic liquid is 5-28:7-8.5:65-85; and the diameter of the circular hole is 3-4 mm.

[0026] In another aspect of the present application, the use of the antibacterial, breathable, hydrophobic and self-cleaning biomimetic fiber tactile sensor is provided, and the biomimetic fiber tactile sensor is applied to wearable devices and object recognition.

[0027] Compared with the prior art, the biomimetic fiber tactile sensor, the preparation method and the application thereof have the following advantages:

[0028] (1) The biomimetic fiber tactile sensor is obtained by integrating fiber as a substrate, ZIF-67 with a highly stable structure, AgNWs with high conductivity and antibacterial properties, and super-hydrophobic stearic acid STA from three aspects of structural design, material selection and preparation process to obtain an electrode layer; a mixed solution containing an ionic liquid with rich anions and cations and high stability is used to obtain an electrolyte layer with different microstructures on both sides, one side being a through-hole and convex combined microstructure, and the other side being an octopus sucker structure; the prepared biomimetic fiber tactile sensor has super-hydrophobicity, can resist the penetration of the solution, thereby prolonging the service life and expanding the application range; the self-cleaning performance can reduce the damage to the surface material of the sensor and effectively remove impurities and other pollutants on the surface of the sensor; at the same time, the electrode layer and the electrolyte layer both have a large number of micropores, allowing the transmission of air / moisture, providing comfort for long-term wear; in addition, the antibacterial performance can maintain the balance of the skin system; and the sensor has good sensitivity and detection range.

[0029] (2) In the ZIF-67 / Ag NWs / STA fiber electrode layer of the application, the fiber with good flexibility is used in a mixed solution of 2-methyl imidazole, cobalt nitrate hexahydrate and methanol, and the ZIF-67 with a highly stable structure is loaded on the fiber by in-situ growth method, the fiber is coated with Ag NWs solution to form a conductive path, and the longitudinal and transverse Ag NWs help to reduce the initial contact area between the electrode and the electrolyte layer, thereby optimizing the performance (such as sensitivity and detection range) of the sensor, and further increasing the antibacterial performance, and then spraying the STA with hydrophobic performance, the stearic acid, to improve the hydrophobicity and self-cleaning performance of the sensor; in addition, the ZIF-67 / Ag NWs / STA fiber electrode layer uses fiber as a base material, and the subsequent processing does not completely block the micropores of the fiber, so it has excellent air permeability;

[0030] (3) In the IL / PVDF electrolyte layer of the application, the mixed solution of ionic liquid containing rich anions and cations and having high stability is formed, and the two sides have different microstructures, one side is a combination structure of different levels of through holes and protrusions (since the heights of the particles on the surface of the sandpaper are inconsistent, the protrusions produced are of different heights, and the gel film is peeled off from the sandpaper, the gel film is relatively thin, and after peeling, holes of different sizes are produced, so there are protrusions and through holes of different levels), and one side is an imitation octopus sucker structure, which effectively reduces the initial contact area between the electrode and the electrolyte, thereby improving the sensing performance and resilience. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 It is a structural schematic diagram of the bionic fiber tactile sensor of the application;

[0032] Figure 2 It is a schematic diagram of the working principle of the bionic fiber tactile sensor of the application;

[0033] Figure 3 It is an electron microscope graph of the ZIF-67 / Ag NWs / STA fiber electrode layer in Example 1 of the application;

[0034] Figure 4 It is an electron microscope graph of the IL / PVDF electrolyte layer in Example 1 of the application;

[0035] Figure 5 In the application, Figure 5 a is a sensor response time detection graph; Figure 5 b is a sensor minimum detection limit graph; Figure 5 c is a sensor stability graph;

[0036] Figure 6 In the application, Figure 6a is a schematic diagram of hydrophobicity display of the biomimetic fiber tactile sensor; Figure 6 b is a schematic diagram of self-cleaning display of the biomimetic fiber tactile sensor;

[0037] Figure 7 a is a schematic diagram of air permeability display of the fiber tactile sensor of the present application;

[0038] Figure 8 b is a schematic diagram of antibacterial property of the fiber tactile sensor of the present application; wherein, Figure 8 a is an antibacterial photo of Staphylococcus aureus; Figure 8 b is an antibacterial property of Staphylococcus aureus; Figure 8 c is a photo of Staphylococcus aureus; Figure 8 d is a killing rate of Staphylococcus aureus; Figure 8 e is an antibacterial photo of Escherichia coli; Figure 8 f is an antibacterial property of Escherichia coli; Figure 8 g is a photo of Escherichia coli; Figure 8 h is a killing rate of Escherichia coli;

[0039] Figure 9 a is a schematic diagram of application of the fiber tactile sensor of the present application; wherein, Figure 9 a is a pulse signal monitoring diagram; Figure 9 b is a finger bending action monitoring diagram; Figure 9 c is an elbow bending action detection diagram; Figure 9 d is object recognition of a sensing array; Figure 9 e is stress distribution of a sensing array.

[0040] BRIEF DESCRIPTION OF DRAWINGS

[0041] 1-IL / PVDF electrolyte, 2-ZIF-67 / Ag NWs / STA fiber electrode layer, 3-ZIF-67, 4-Ag NWs, 5-STA. DETAILED DESCRIPTION

[0042] Unless otherwise defined, the technical terms used in the following examples have the same meanings as commonly understood by those skilled in the art to which the present application belongs. The experimental reagents used in the following examples, unless otherwise specified, are all conventional biochemical reagents; the experimental methods described, unless otherwise specified, are all conventional methods.

[0043] The present application will be described in detail below with reference to the examples and drawings.

[0044] A preparation method of an antibacterial, air-permeable, hydrophobic, self-cleaning biomimetic fiber tactile sensor, comprising the following steps:

[0045] S1, preparing a ZIF-67 / Ag NWs / STA fiber electrode layer

[0046] 1) placing the fiber into a mixed solution of 2-methylimidazole, cobalt nitrate hexahydrate and methanol, loading ZIF-67 onto the fiber by in-situ growth method to obtain ZIF-67 fiber; wherein in the mixed solution of 2-methylimidazole, cobalt nitrate hexahydrate and methanol, the molar ratio of 2-methylimidazole to cobalt nitrate hexahydrate is 2-3:5-15, and the molar concentration of 2-methylimidazole in methanol is 0.25-1 mol / l;

[0047] 2) coating the Ag NWs solution with high conductivity and antibacterial properties on both surfaces of the ZIF-67 fiber to obtain the ZIF-67 / Ag NWs fiber after drying; wherein the concentration of the Ag NWs solution is 4-7 mg / mL;

[0048] 3) spraying the stearic acid solution on one surface of the ZIF-67 / Ag NWs fiber to obtain the ZIF-67 / Ag NWs / STA fiber electrode layer after drying; wherein the mass ratio of STA to water in the stearic acid solution is 1:100-125;

[0049] S2, preparing an IL / PVDF electrolyte layer

[0050] A plurality of circular holes with a diameter of 3-4 mm are cut on the sandpaper using a laser cutting machine, and then a mixed solution containing an ionic liquid is coated on the surface of the sandpaper, and the IL / PVDF electrolyte layer is obtained after drying and peeling; wherein the mass ratio of [EMIM][TFSI], P(VDF-HFP) and DMF in the mixed solution containing the ionic liquid is 5-28:7-8.5:65-85;

[0051] S3, coating IL / PVDF solution as glue on both surfaces of the IL / PVDF electrolyte layer prepared in S2, and then respectively adhering the ZIF-67 / Ag NWs / STA fiber electrode layer prepared in S1 on both surfaces of the IL / PVDF electrolyte layer, and obtaining the biomimetic fiber tactile sensor after drying; wherein the non-hydrophobic modified surface of the ZIF-67 / Ag NWs / STA fiber electrode layer faces the IL / PVDF electrolyte layer.

[0052] As Figure 1As shown, the bionic fiber tactile sensor includes an IL / PVDF electrolyte layer 1 located in the middle layer, a ZIF-67 / Ag NWs / STA fiber electrode layer 2 arranged on one side of the IL / PVDF electrolyte layer 1, and a ZIF-67 / Ag NWs / STA fiber electrode layer 2 arranged on the other side of the IL / PVDF electrolyte layer 1; wherein, the IL / PVDF electrolyte layer 1 is loaded with ions, one side is a combined microstructure of through holes and protrusions, and the other side is an octopus suction cup structure; the ZIF-67 / Ag NWs / STA fiber electrode layer 2 is based on fiber, loaded with ZIF-673 with a highly stable structure, and coated on both sides with highly conductive and antibacterial Ag NWs 4, and then the outward side is hydrophobically modified by superhydrophobic stearic acid STA 5.

[0053] like Figure 2 As shown, the working principle of the bionic fiber tactile sensor is as follows: when pressure is applied to the bionic fiber tactile sensor, the ZIF-67 / Ag NWs / STA fiber electrode layer and the IL / PVDF electrolyte layer will deform under the action of pressure, resulting in an increase in the contact area and a decrease in the distance between the IL / PVDF electrolyte layer and the ZIF-67 / Ag NWs / STA fiber electrode layer, causing an increase in capacitance; when the external pressure disappears, the ZIF-67 / Ag NWs / STA fiber electrode layer and the IL / PVDF electrolyte layer will return to their original state, 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 to monitor the magnitude of the force.

[0054] Example 1

[0055] The preparation of a bionic fiber tactile sensor comprises the following steps:

[0056] S1. Preparation of ZIF-67 / Ag NWs / STA fiber electrode layer

[0057] 1) Mixing 25 mL of methanol solution with 0.025 M cobalt nitrate hexahydrate, and then pouring a mixed solution of 25 mL of methanol solution and 0.1 M 2-methylimidazole into the above solution; immersing clean fibers in the mixed solution of 2-methylimidazole, cobalt nitrate hexahydrate, and methanol and allowing to stand at room temperature for 48-52 hours; then drying the treated fibers at 60° C. for 30 minutes to obtain ZIF-67 fibers;

[0058] 2) 5 mg / mL Ag NWs dispersion was evenly sprayed onto ZIF-67 fibers and then dried in an oven at 60°C for 30 min to obtain ZIF-67 / Ag NWs fibers;

[0059] 3) Under magnetic stirring at 1500 rpm, stearic acid (STA) and hot water were added into a beaker in a proportion of 1:125 by mass, and stirred in a 1000 rpm magnetic stirring water bath at 70℃ for 1 hour to obtain a stearic acid emulsion; the freshly prepared stearic acid emulsion was sprayed onto one face of the ZIF-67 / Ag NWs fiber, and then dried in an oven at 60℃ for 30 minutes to obtain a ZIF-67 / Ag NWs / STA fiber electrode layer;

[0060] S2, preparation of IL / PVDF electrolyte layer

[0061] [EMIM][TFSI], P(VDF-HFP) and DMF were added into a beaker in a weight ratio of 16:7.7:76.3, and then the beaker was sealed with a plastic wrap to prevent possible evaporation and exchange of substances with the outside; the IL / PVDF mixed solution was stirred in a magnetic stirring water bath at 60℃ for 3 hours until the solution became transparent, which indicated that the polymer particles were completely dissolved; a laser cutting machine was used to cut multiple circular holes with a diameter of 3 mm on sandpaper, and the spacing between each hole was 4 mm; the IL / PVDF mixed solution was poured onto the sandpaper, and then peeled off after drying in an oven at 60℃ for 3 hours to obtain an IL / PVDF electrolyte layer;

[0062] S3, IL / PVDF solution was applied as glue on both sides of the IL / PVDF electrolyte layer prepared in S2, and then the ZIF-67 / Ag NWs / STA fiber electrode layer prepared in S1 was attached to each side of the IL / PVDF electrolyte layer, and dried in an oven at 60℃ for 20 minutes to obtain the biomimetic fiber tactile sensor.

[0063] Example 2

[0064] Based on Example 1, the difference between Example 1 is that when preparing the IL / PVDF electrolyte layer, the content of the ionic liquid is different, [EMIM][TFSI], P(VDF-HFP), DMF are prepared in a mass ratio of 8:8.3:83.7.

[0065] Example 3

[0066] Based on Example 1, the difference between Example 1 is that when preparing the IL / PVDF electrolyte layer, the content of the ionic liquid is different, [EMIM][TFSI], P(VDF-HFP), DMF are prepared in a mass ratio of 24:7.1:68.9.

[0067] Comparative Example 1

[0068] On the basis of example 1, different from example 1 is that when preparing IL / PVDF electrolyte layer, the content of ionic liquid is different, [EMIM][TFSI], P(VDF-HFP), DMF are prepared according to the mass ratio of 32:6.7:61.3.

[0069] Example 4

[0070] On the basis of example 1, different from example 1 is that when preparing IL / PVDF electrolyte layer, the diameter of the round hole cut on the sandpaper by the laser cutting machine is 4mm.

[0071] Comparative example 2

[0072] On the basis of example 1, different from example 1 is that when preparing IL / PVDF electrolyte layer, no round hole is cut, and the ionic solution is directly coated on the surface of the sandpaper.

[0073] Comparative example 3

[0074] On the basis of example 1, different from example 1 is that when preparing IL / PVDF electrolyte layer, the diameter of the round hole cut on the sandpaper by the laser cutting machine is 2mm.

[0075] Sensitivity test is carried out on examples 1-3 and comparative example 1, to study the influence of different content of ionic liquid in IL / PVDF electrolyte layer on the sensitivity of the prepared bionic fiber tactile sensor, and the data is shown in table 1.

[0076] Table 1

[0077]

[0078] From table 1, it can be seen that when the ratio of P(VDF-HFP) / DMF is constant, it shows that different proportions of ionic liquid content in IL / PVDF electrolyte layer will affect the performance of the sensor; with the increase of the content of ionic liquid, the performance of the sensor gradually improves. But when the content of ionic liquid is too much, it will cause the phenomenon of liquid flowing out of IL / PVDF electrolyte, and it cannot form an electrolyte with a breathable solid film.

[0079] Sensitivity test is carried out on examples 1, 4 and comparative examples 2, 3, to study the influence of the round hole with different diameters cut on the sandpaper by the laser cutting machine in IL / PVDF electrolyte layer on the sensitivity of the prepared bionic fiber tactile sensor, and the data is shown in table 2.

[0080] Table 2

[0081]

[0082] As can be seen from Table 2, the performance (such as sensitivity, detection range) of the sensor can be improved by cutting a circular hole on the sandpaper by using a laser cutting machine and introducing an imitation octopus sucker structure into the IL / PVDF electrolyte layer; however, when the diameter of the circular hole cut by the laser cutting machine is too large, the imitation octopus sucker structure of the IL / PVDF electrolyte layer will be too large, which will cause the initial contact between the electrolyte layer and the electrode layer to be larger, thereby causing the performance of the sensor to decrease; at the same time, if the size of the circular hole is too small, the performance of the sensor will not be as good as that of the sensor with only one side of the protruding microstructure, and therefore a suitable size of the circular hole is extremely important for improving the performance.

[0083] Performance test of the prepared bionic fiber tactile sensor

[0084] 1. As shown in Figure 3 , the electron microscope image of the ZIF-67 / Ag NWs / STA fiber electrode layer prepared in Example 1, the highly stable cubic structure ZIF-67 is loaded to the fiber by in-situ growth method, which not only retains its inherent fiber structure, but also endows it with excellent antibacterial performance and micro-nano structure, and then the introduction of Ag NWs with high conductivity and antibacterial performance can form a conductive path for the fiber and increase the antibacterial performance, and the introduction of super-hydrophobic STA sheet structure can improve the hydrophobicity and self-cleaning performance of the sensor;

[0085] As shown in Figure 4 , the electron microscope image of the IL / PVDF electrolyte layer prepared in Example 1, the front side has a combination of through holes and protrusions of different levels of height microstructure, and the back side has an imitation octopus sucker structure, which can effectively reduce the initial contact area between the electrode and the electrolyte, thereby improving the sensitivity; in addition, the imitation octopus sucker structure can increase the height of the electrolyte layer, so that the resilience is better.

[0086] 2. As shown in Figure 5 , taking the bionic fiber tactile sensor prepared in Example 1 as an example, the bionic fiber tactile sensor has an ultrafast response time and recovery time of 100 ms and 75 ms Figure 5 (a is a sensor response time detection diagram); has an ultra-low detection limit of 25 Pa Figure 5 (b is a sensor minimum detection limit diagram); has excellent stability, and the reciprocating experiment has basically no error Figure 5 (c is a sensor stability diagram).

[0087] 3. As shown in Figure 6 , the bionic fiber tactile sensor prepared by the present application has good hydrophobicity Figure 6a is the hydrophobicity diagram of the sensor, the contact angle between the fiber sensor and artificial sweat is 162.5°, the contact angle with beer is 161.8°, the contact angle with juice is 161.8°, the contact angle with tea is 162.3°, the contact angle with water is 164.2°, and the contact angle with milk is 160.4°; the bionic fiber tactile sensor prepared by the application has good self-cleaning property, and the vegetable powder on the surface of the sensor can quickly slide off with water droplets Figure 6 b is the self-cleaning diagram of the sensor.

[0088] 4. As shown in Figure 7 , the bionic fiber tactile sensor prepared by the application has excellent air permeability, and after the sensor is fixed on the head of a hair dryer, air can pass through the sensor to make the dandelion sway.

[0089] 5. As shown in Figure 8 , the bionic fiber tactile sensor prepared by the application has excellent antibacterial property; the surface and surrounding of the fiber, ZIF-67 fiber, ZIF-67 / Ag NWs fiber and ZIF-67 / Ag NWs / STA fiber are covered with staphylococcus aureus, and after 24 hours, an antibacterial zone is formed around the ZIF-67 fiber, ZIF-67 / Ag NWs fiber and ZIF-67 / Ag NWs / STA fiber; however, in sharp contrast, no antibacterial zone is formed around the fiber, indicating that ZIF-67 and AgNWs significantly inhibit bacterial proliferation Figure 8 a is the antibacterial photo of staphylococcus aureus); the synergistic antibacterial effect of ZIF-67 and Ag NWs makes the antibacterial ring diameter of ZIF-67 / Ag NWs fiber the highest (1.21±0.2mm); however, after spraying STA nanosheets, the antibacterial property of ZIF-67 / Ag NWs / STA fiber is reduced, but it can still inhibit bacterial growth Figure 8 b is the antibacterial property of staphylococcus aureus); then, the killing rate of staphylococcus aureus on the fiber, ZIF-67 fiber, ZIF-67 / Ag NWs fiber and ZIF-67 / Ag NWs / STA fiber is tested Figure 8 c and Figure 8 d are the photo and killing rate of staphylococcus aureus); the killing rate of ZIF-67 / Ag NWs fiber on staphylococcus aureus is the highest (the fewer the particles in the field of view, the higher the killing rate); in addition, E. coli detection is carried out on the fiber, ZIF-67 fiber, ZIF-67 / Ag NWs fiber and ZIF-67 / Ag NWs / STA fiber; an antibacterial zone is formed around the ZIF-67 fiber, ZIF-67 / Ag NWs fiber and ZIF-67 / Ag NWs / STA fiber, among which the antibacterial zone around the ZIF-67 / Ag NWs fiber is the largestFigure 8 e and Figure 8 f are the photographs and performance of E. coli); in addition, the kill rate of ZIF-67 fiber is about 46%, the kill rate of ZIF-67 / Ag NWs fiber is about 99%, and the kill rate of ZIF-67 / Ag NWs / STA fiber is about 98% Figure 8 g and Figure 8 h are the photographs and kill rate of E. coli.

[0090] 6. The biomimetic fiber tactile sensor prepared by the method according to any one of claims 1-5 is used as a sensor unit for monitoring the health status of human body and detecting motion in daily life Figure 9 As shown in the drawings, the biomimetic fiber tactile sensor prepared by the method according to any one of claims 1-5 is not only used as a sensor unit for monitoring the health status of human body and detecting motion in daily life Figure 9 a is a pulse signal monitoring diagram, Figure 9 b is a finger bending motion monitoring diagram, Figure 9 c is an elbow bending motion detection diagram), and also used as a sensing array for recognizing the spatial pressure distribution of human-computer interaction Figure 9 d and 9e are object recognition and stress distribution of the sensing array.

[0091] The biomimetic fiber sensor prepared by the method has superhydrophobicity, which can resist the penetration of solution (e.g., sweat), thereby prolonging the service life and expanding the application range; the self-cleaning performance can reduce the damage to the surface material of the sensor and effectively remove impurities and other pollutants on the surface of the sensor; at the same time, the electrode layer and the electrolyte layer have a large number of micropores, allowing the transmission of air / moisture, providing comfort for long-term wearing; in addition, the sensor has antibacterial performance, which can maintain the balance of the skin system.

[0092] The above only describes the preferred embodiments of the present application and should not be used to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. An antibacterial, breathable, hydrophobic, self-cleaning bionic fiber tactile sensor, characterized in that: include: ZIF-67 / Ag NWs / STA fiber electrode layer, wherein the ZIF-67 / Ag NWs / STA fiber electrode layer is based on a fiber substrate, loaded with ZIF-67, coated on both sides with Ag NWs, and then hydrophobically modified on one side with STA; An IL / PVDF electrolyte layer, wherein the IL / PVDF electrolyte layer is loaded with ions, has a microstructure composed of through holes and protrusions on one side, and has an octopus-like suction cup structure on the other side; There are two ZIF-67 / Ag NWs / STA fiber electrode layers, which are respectively attached to the two surfaces of the IL / PVDF electrolyte layer, and the non-hydrophobically modified side of the ZIF-67 / Ag NWs / STA fiber electrode layer faces the IL / PVDF electrolyte layer.

2. The antibacterial, breathable, hydrophobic, self-cleaning bionic fiber tactile sensor according to claim 1, characterized in that: The ZIF-67 / Ag NWs / STA fiber electrode layer is prepared by loading ZIF-67 on the fiber by an in-situ growth method in a mixed solution of 2-methylimidazole, cobalt nitrate hexahydrate and methanol, coating Ag NWs solution on both sides, drying, and then spraying a hydrophobic STA solution on one side and drying.

3. The antibacterial, breathable, hydrophobic, self-cleaning bionic fiber tactile sensor according to claim 2, characterized in that: In the mixed solution of 2-methylimidazole, cobalt nitrate hexahydrate and methanol, the molar ratio of 2-methylimidazole to cobalt nitrate hexahydrate is 2-3:5-15, and the molar concentration of 2-methylimidazole in methanol is 0.25-1 mol / l; The concentration of the Ag NWs solution is 4-7 mg / mL; The mass ratio of STA to water in the hydrophobic STA solution is 1:100-125.

4. The antibacterial, breathable, hydrophobic, self-cleaning bionic fiber tactile sensor according to claim 1, characterized in that: The IL / PVDF electrolyte layer is obtained by coating a mixed solution containing an ionic liquid on sandpaper provided with a plurality of circular holes, and then peeling it off after drying.

5. The antibacterial, breathable, hydrophobic, self-cleaning bionic fiber tactile sensor according to claim 4, characterized in that: The mass ratio of [EMIM][TFSI], P(VDF-HFP) and DMF in the mixed solution containing the ionic liquid is 5-28:7-8.5:65-85.

6. The antibacterial, breathable, hydrophobic, self-cleaning bionic fiber tactile sensor according to claim 4, characterized in that: The diameter of the circular hole is 3-4 mm.

7. A method for preparing an antibacterial, breathable, hydrophobic, self-cleaning bionic fiber tactile sensor, characterized in that: The steps include: S1. Preparation of ZIF-67 / Ag NWs / STA fiber electrode layer The fiber was placed in a mixed solution of 2-methylimidazole, cobalt nitrate hexahydrate, and methanol, and ZIF-67 was loaded onto the fiber by an in situ growth method to obtain ZIF-67 fiber; an Ag NWs solution was coated on both sides of the ZIF-67 fiber, and after drying, ZIF-67 / Ag NWs fiber was obtained; a stearic acid solution was sprayed on one side of the ZIF-67 / Ag NWs fiber, and after drying, the ZIF-67 / Ag NWs / STA fiber electrode layer was obtained; S2. Preparation of IL / PVDF electrolyte layer Cutting a plurality of circular holes on sandpaper, applying a mixed solution containing an ionic liquid on the surface of the sandpaper, drying, and peeling off to obtain the IL / PVDF electrolyte layer; S3. Apply IL / PVDF solution as glue on both surfaces of the IL / PVDF electrolyte layer prepared in S2, and then adhere the ZIF-67 / Ag NWs / STA fiber electrode layers prepared in S1 on both surfaces of the IL / PVDF electrolyte layer, and obtain the bionic fiber tactile sensor after drying; wherein the non-hydrophobically modified side of the ZIF-67 / Ag NWs / STA fiber electrode layer faces the IL / PVDF electrolyte layer.

8. The method for preparing the antibacterial, breathable, hydrophobic, self-cleaning bionic fiber tactile sensor according to claim 7, characterized in that: In S1, in the mixed solution of 2-methylimidazole, cobalt nitrate hexahydrate and methanol, the molar ratio of 2-methylimidazole to cobalt nitrate hexahydrate is 2-3:5-15, and the molar concentration of 2-methylimidazole in methanol is 0.25-1 mol / l; the concentration of the Ag NWs solution is 4-7 mg / mL; and the mass ratio of STA to water in the stearic acid solution is 1:100-125.

9. The method for preparing the antibacterial, breathable, hydrophobic, self-cleaning bionic fiber tactile sensor according to claim 7, characterized in that: In the S2, the mass ratio of [EMIM][TFSI], P(VDF-HFP), and DMF in the mixed solution containing the ionic liquid is 5-28:7-8.5:65-85; and the diameter of the circular hole is 3-4 mm.

10. Use of the antibacterial, breathable, hydrophobic, self-cleaning bionic fiber tactile sensor according to any one of claims 1 to 6, or the antibacterial, breathable, hydrophobic, self-cleaning bionic fiber tactile sensor prepared by the preparation method according to any one of claims 7 to 9, characterized in that: Application of the bionic fiber tactile sensor in wearable devices and object recognition.

Images