Fabric interdigital pressure sensor based on conductive polymer material and preparation method thereof

Abstract

The application belongs to the technical field of pressure measurement, and particularly discloses a fabric interdigital pressure sensor based on a conductive polymer material and a preparation method thereof. The pressure sensor comprises a sensing structure unit and a flexible insulating layer, wherein the sensing structure unit comprises a first interdigital electrode and a second interdigital electrode, the fingers of the first interdigital electrode and the fingers of the second interdigital electrode are parallel to each other, and are cross-woven to form a textile fabric structure through a flexible non-conductive fiber; or the fingers of the first interdigital electrode and the fingers of the second interdigital electrode are arranged orthogonally and cross-woven to form a textile fabric structure; the first interdigital electrode and the second interdigital electrode are both made of a flexible conductive fiber; both surfaces of the textile fabric structure are coated with a flexible conductive polymer composite material; and the flexible insulating layer covers the sensing structure unit. The pressure sensor can simultaneously meet the requirements of high sensitivity, a large pressure measurement range, high mechanical strength and full flexibility of the sensor.

Description

Technical Field

[0001] This invention belongs to the field of pressure measurement technology, and specifically relates to a fabric interdigital pressure sensor based on conductive polymer material and its preparation method. Background Technology

[0002] A pressure sensor is a device or apparatus that can sense pressure signals and convert them into usable output electrical signals according to certain rules.

[0003] Most existing conductive polymer composite pressure sensors have a pressure testing range of 0.001 MPa to 5.0 MPa, resulting in a narrow measurement range. While sensors using buffer materials and encapsulation structures can significantly increase the sensor's range, they suffer from poor flexibility. A very small number of large-range nano-conductive polymer composite pressure sensors, employing multi-layer fabric structures, can achieve pressure measurements in the range of 0 MPa to 50 MPa, but these sensors have a small resistance variation range and relatively low sensitivity. Using interdigitated electrodes as piezoelectric material coatings can greatly improve sensor sensitivity, but this narrows the pressure measurement range.

[0004] Therefore, existing conductive polymer composite pressure sensors cannot simultaneously meet the performance requirements of high sensitivity, wide pressure measurement range, high mechanical strength, and full sensor flexibility. These limitations restrict the application of currently industrialized conductive polymer composite pressure sensors in fields such as smart wearables, mechanical engineering, network communication, and transportation engineering. Summary of the Invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a fabric interdigital pressure sensor based on conductive polymer material and its preparation method, wherein the pressure sensor can simultaneously meet the requirements of high sensitivity, large pressure measurement range, high mechanical strength and full flexibility.

[0006] The inventive concept of this invention is as follows: Flexible conductive fibers and flexible non-conductive fibers with piezoelectric effect and a bilayer structure are fully encapsulated by a flexible conductive polymer composite material. Utilizing the fully conductive properties of the inner layer of the flexible conductive fiber, it is made into the fingers of the interdigitated electrode, greatly improving the sensitivity of the pressure sensor. The flexible non-conductive fiber, through blending with the flexible conductive fiber, provides the pressure sensor with higher mechanical properties and flexibility. The textile fabric structure formed by the blending of flexible conductive and flexible non-conductive fibers, or a textile fabric structure formed by the interlacing of flexible conductive fibers, serves as a skeletal support, improving the mechanical properties, tensile and compressive flexibility of the sensing structural unit. Furthermore, since the pressure sensor is made and encapsulated using fully flexible materials, it also possesses full flexibility.

[0007] To address the aforementioned technical problems, a first aspect of the present invention provides a pressure sensor, comprising:

[0008] The sensing structure unit includes a first interdigital electrode and a second interdigital electrode. The fingers of the first interdigital electrode and the fingers of the second interdigital electrode are parallel to each other and are formed into a textile fabric structure by cross-weaving flexible non-conductive fibers; or the fingers of the first interdigital electrode and the fingers of the second interdigital electrode are orthogonally arranged and cross-weaved to form a textile fabric structure; both the first interdigital electrode and the second interdigital electrode are made of flexible conductive fibers; both sides of the textile fabric structure are coated with a flexible conductive polymer composite material.

[0009] A flexible insulating layer that covers the sensing structure unit.

[0010] As a further improvement to the above scheme, the raw material components of the flexible conductive polymer composite material include, by weight: 100 parts of flexible polymer matrix and 4-8 parts of nano-conductive filler.

[0011] Preferably, the elongation at break of the flexible polymer matrix is ​​20%-500%.

[0012] Preferably, the flexible polymer matrix is ​​selected from any one of polydimethylsiloxane (PDMS), two-component liquid silicone (A&B two-component), two-component polyurethane (PU), and two-component polyurethane elastomer (TPU). These polymer materials all have good mechanical properties and flexibility. Meanwhile, the curing agent can be selected from those compatible with the flexible polymer matrix.

[0013] Preferably, the nano-conductive filler is selected from at least one of nano-superconducting carbon black, nano-conductive multi-walled carbon nanotubes, and conductive graphene. The threshold value of the conductive filler is between 4.0% and 7.5%, and all of these conductive fillers have good compatibility with the flexible polymer matrix.

[0014] As a further improvement to the above solution, the flexible conductive fiber includes a flexible conductive fiber thread and the flexible conductive polymer composite material, wherein the flexible conductive polymer composite material covers the flexible conductive fiber thread.

[0015] Preferably, the diameter of the flexible conductive fiber is 0.02mm-0.1mm.

[0016] Preferably, the flexible conductive fiber is made of conductive polymer fiber or non-conductive polymer fiber with a conductive metal coating on its surface. The flexible conductive fiber has excellent conductivity; when stretched by 2%-50%, the resistance change is minimal.

[0017] Preferably, the conductive polymer fiber is selected from at least one of polyaniline, polythiophene, polyacetylene, and polypyrrole;

[0018] Preferably, the conductive metal is selected from at least one of silver, copper, nickel, and zinc;

[0019] Preferably, the non-conductive polymer fiber is selected from at least one of nylon, polyester, and spandex.

[0020] As a further improvement to the above solution, the flexible non-conductive fiber includes a flexible non-conductive fiber thread and the flexible conductive polymer composite material, wherein the flexible conductive polymer composite material covers the flexible non-conductive fiber thread.

[0021] Preferably, the diameter of the flexible non-conductive fiber is 0.01mm-0.08mm.

[0022] Preferably, the flexible non-conductive fiber is made of non-conductive polymer fiber.

[0023] Preferably, the non-conductive polymer fiber is selected from at least one of nylon, polyester, spandex, and silk fiber.

[0024] Preferably, the flexible insulating layer is made of any one of silicone, polyethylene terephthalate (PET), or polyimide (PI).

[0025] Preferably, the thickness of the sensing structure unit is 0.2mm-2.0mm.

[0026] A second aspect of the present invention provides a method for manufacturing a pressure sensor, comprising the following steps:

[0027] (1) The first interdigital electrode and the second interdigital electrode made of flexible conductive fiber are woven into a textile fabric structure; or the first interdigital electrode and the second interdigital electrode are woven into a textile fabric structure by flexible non-conductive fiber; and then a flexible conductive polymer composite material is coated on both sides of the textile fabric structure, and after curing, a sensing structure unit with dual wires is formed.

[0028] (2) The sensing structure unit is covered with a flexible insulating material to form a flexible insulating layer, thereby obtaining the pressure sensor.

[0029] Specifically, this invention creatively integrates interdigitated electrodes and fabric structures into a single unit, utilizing the skeletal structure formed by the blended fabric to enhance the mechanical strength and flexibility of the conductive material, while retaining the interdigitated or cross structure, thus greatly improving the sensitivity and stability of the sensor.

[0030] As a further improvement to the above scheme, the preparation process of the flexible conductive fiber is as follows: a flexible polymer matrix, nano-conductive filler and curing agent are mixed in a mass ratio, and after degassing treatment, an uncured flexible conductive polymer composite material is obtained; the flexible conductive fiber line is subjected to hydroxylation treatment, sprayed with silane coupling agent, and then immersed in the flexible conductive polymer composite material. After being taken out, it is cured to form a flexible conductive fiber line with an outer layer of flexible conductive polymer composite material; the process of repeated immersion and curing is then repeated to obtain the flexible conductive fiber.

[0031] Preferably, the hydroxylation treatment is performed using plasma surface treatment.

[0032] Preferably, the curing conditions are: temperature of 110℃-130℃ and curing time of 8min-12min.

[0033] As a further improvement to the above scheme, the preparation process of the flexible non-conductive fiber is as follows: the flexible non-conductive fiber line is processed using the same preparation method as the flexible conductive fiber, that is, the flexible conductive fiber line in the preparation process of the flexible conductive fiber is simply replaced with the flexible non-conductive fiber line.

[0034] Compared with the prior art, the above-described technical solution of the present invention has at least the following technical effects or advantages:

[0035] (1) The pressure sensor of the present invention cleverly integrates the interdigital electrode structure with the fabric skeleton structure. It uses a flexible conductive polymer composite material to fully encapsulate flexible conductive fibers and flexible non-conductive fibers with piezoelectric effect and double-layer structure. The inner layer of flexible conductive fibers with fully conductive properties serves as the fingers of the interdigital electrodes, thereby improving the sensitivity of the pressure sensor. At the same time, the flexible non-conductive fibers and flexible conductive fibers are blended to form a textile fabric structure, or both are formed by interlacing flexible conductive fibers to form a textile fabric structure, which improves the mechanical properties, tensile and compressive flexibility of the sensing structure unit. Moreover, the pressure sensor is made of fully flexible materials, thus possessing full flexibility. In addition, the outermost layer of the pressure sensor is encapsulated with flexible insulating material, which acts as a buffer structure, improves the pressure sensor's ability to resist external interference and corrosion, and significantly improves the problem of local stress concentration.

[0036] (2) The pressure sensor of the present invention effectively solves the technical problem that traditional conductive polymer composite pressure sensors cannot simultaneously achieve sensitivity, range and flexibility. It has the characteristics of full flexibility, high sensitivity, good linearity, good durability and wide range. It can realize dynamic monitoring of multiple forces in various complex situations and has broad application prospects in fields such as 5G Internet of Things, automobiles, robots, smart wearables, medical health, smart homes, smart living, mechanical engineering and traffic safety. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the structure of the first interdigital electrode and the second interdigital electrode;

[0038] Figure 2 One of the schematic diagrams of the structure of a fabric interdigitated electrode textile.

[0039] Figure 3 The second schematic diagram of the structure of the interdigitated electrode textile fabric.

[0040] Figure 4 The third schematic diagram of the structure of a fabric interdigitated electrode textile fabric;

[0041] Figure 5 Schematic diagram of the structure of interdigitated fabric electrodes in textile fabric (Part 4);

[0042] Figure 6 This is a schematic diagram of the pressure sensor structure;

[0043] Figure 7 This is a graph showing the resistance R0 / R change of the pressure sensor under cyclic loading.

[0044] Wherein: 100 is the first interdigital electrode, 101 is the first electrode, 102 is the first interdigital part, 200 is the second interdigital electrode, 201 is the second electrode, 202 is the second interdigital part, 301 is the longitudinal fiber, 302 is the transverse fiber, 400 is the sensing structure unit, and 500 is the flexible insulating layer. Detailed Implementation

[0045] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments to facilitate understanding of the invention by those skilled in the art. It is particularly important to note that the embodiments are merely illustrative of the invention and should not be construed as limiting the scope of protection of the invention. Non-essential improvements and adjustments made to the invention by those skilled in the art based on the above description should still fall within the scope of protection of the present invention.

[0046] Many specific details are set forth in the following description to provide a thorough understanding of the invention. However, the invention may be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below. Furthermore, all raw materials mentioned below, unless otherwise specified, are commercially available products; all process steps or preparation methods not mentioned in detail are process steps or preparation methods known to those skilled in the art.

[0047] Furthermore, the descriptions of "first," "second," etc., in the embodiments of the present invention are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated.

[0048] The following reference Figure 1-6 The present invention describes sensors and their fabrication methods according to some embodiments.

[0049] 1. Flexible conductive fiber

[0050] Flexible conductive fibers include flexible conductive fiber strands and flexible conductive polymer composites, with the flexible conductive polymer composites coating the flexible conductive fiber strands. The flexible conductive fibers exhibit piezoelectric effect and a bilayer structure. The inner layer of flexible conductive fiber strands has a diameter between 0.02 mm and 0.1 mm, exhibiting good conductivity and minimal resistance change when the elongation is between 2% and 50%. The outer layer, a piezoelectric flexible conductive polymer composite, is prepared from a flexible polymer matrix, nano-conductive fillers, and a curing agent. It possesses high flexibility, strong bonding, low viscosity before curing, and excellent piezoelectric effect after curing. The thickness of the outer layer is between 0.01 mm and 0.05 mm. The final flexible conductive fiber has a diameter between 0.05 mm and 0.20 mm.

[0051] A method for preparing flexible conductive fibers includes the following steps:

[0052] First, a flexible polymer matrix, nano-conductive filler, and curing agent are mixed uniformly according to a mass ratio and degassed to form an uncured flexible conductive polymer composite material. Then, flexible conductive fiber threads with tensile strength and tensile strain are subjected to plasma surface treatment to reduce the surface energy of the flexible conductive fiber threads, and a small amount of silane coupling agent is sprayed to enhance the bonding force between the flexible conductive fiber threads and the flexible conductive polymer composite material. Finally, the treated flexible conductive fiber threads are immersed in the uncured flexible conductive polymer composite material, removed, and excess flexible conductive polymer composite material is removed. The mixture is then cured at 110℃-130℃ for 8-12 minutes to form a flexible conductive fiber thread with an outer layer of flexible conductive polymer composite material. This process of immersion, coating, and curing with another layer of flexible conductive polymer composite material is repeated to ensure that the outer layer of the flexible conductive fiber thread is completely covered by the flexible conductive polymer composite material, thus obtaining flexible conductive fibers.

[0053] 2. Flexible non-conductive fibers

[0054] Flexible non-conductive fibers include flexible non-conductive fiber yarns and flexible conductive polymer composite materials, with the flexible conductive polymer composite material coating the flexible non-conductive fiber yarns. The flexible non-conductive fibers exhibit piezoelectric effect and a bilayer structure. The inner layer of flexible non-conductive fiber yarns has a diameter between 0.01 mm and 0.08 mm, possessing high flexibility and mechanical strength. The outer layer, coated with a piezoelectric flexible conductive polymer composite material, has a coating thickness between 0.01 mm and 0.08 mm. The final flexible non-conductive fiber has a diameter between 0.05 mm and 0.20 mm.

[0055] Preparation method of flexible non-conductive fiber: The non-conductive flexible fiber thread with higher flexibility and mechanical strength is processed by the same preparation method as that of flexible conductive fiber to obtain flexible non-conductive fiber.

[0056] 3. Sensing Structure Unit

[0057] The sensing structure unit includes a first interdigital electrode and a second interdigital electrode, wherein the fingers of the first interdigital electrode and the fingers of the second interdigital electrode are parallel to each other and are formed into a textile fabric structure by cross-weaving flexible non-conductive fibers; or the fingers of the first interdigital electrode and the fingers of the second interdigital electrode are orthogonally arranged and cross-weaved to form a textile fabric structure; and both sides of the textile fabric structure are coated with a flexible conductive polymer composite material.

[0058] like Figure 1 As shown, the first interdigital electrode 100, made of flexible conductive fiber, includes a first electrode 101 and a first interdigital portion 102; the second interdigital electrode 200, made of flexible conductive fiber, includes a second electrode 201 and a second interdigital portion 202, wherein the first interdigital portion 102 and the second interdigital portion 202 form an interdigital structure.

[0059] like Figure 2-4 As shown, the first interdigitated portion 102 and the second interdigitated portion 202 are parallel to each other. The flexible non-conductive fiber includes longitudinal fiber 301 and transverse fiber 302, which are perpendicular to each other. The flexible non-conductive fiber is blended with the first interdigitated portion 102 and the second interdigitated portion 202 through weaving to form a textile fabric structure with a certain strength and piezoelectric effect.

[0060] like Figure 2 As shown, the first interdigitated portion 102 and the second interdigitated portion 202 are spaced apart, and the longitudinal fiber 301 is sandwiched between the adjacent first interdigitated portion 102 and the second interdigitated portion 202. The transverse fiber 302 is woven with the first interdigitated portion 102, the second interdigitated portion 202 and the longitudinal fiber 301 one by one to form a textile fabric structure.

[0061] like Figure 3As shown, the first forked portion 102 and the second forked portion 202 are arranged adjacent to each other, and the transverse fiber 302 is woven with the first forked portion 102 and the second forked portion 202 one by one to form a textile fabric structure.

[0062] like Figure 4 As shown, the first interdigitated portion 102 and the second interdigitated portion 202 are spaced apart, and the longitudinal fiber 301 is sandwiched between the adjacent first interdigitated portion 102 and the second interdigitated portion 202. The transverse fiber 302 is woven with the first interdigitated portion 102, the second interdigitated portion 202 and the longitudinal fiber 301 in a woven manner, forming a textile fabric structure at every two cross-weaves.

[0063] like Figure 5 As shown, the first forked finger portion 102 and the second forked finger portion 202 are arranged orthogonally to each other, and the first forked finger portion 102 and the second forked finger portion 202 are interwoven to form a textile fabric structure.

[0064] The textile fabric structure combines good friction and flexibility, and the weaving process does not damage the structure of the flexible conductive and non-conductive fiber coatings, nor does it alter the interdigitated or crossed structural layout of the first and second interdigitated electrodes. The blended woven textile fabric structure includes, but is not limited to, […]. Figure 2-5 As shown.

[0065] 4. Pressure sensor

[0066] like Figure 6 As shown, the pressure sensor includes a sensing structure unit 400 and a flexible insulating layer 500, and the flexible insulating layer 500 covers the pressure sensing unit 400.

[0067] The method for manufacturing a pressure sensor includes the following steps:

[0068] (1) A flexible conductive polymer composite material is coated on both sides of the textile fabric structure formed by the above blending to fully fill the gaps in the textile fabric structure, and cured at 110℃-130℃ for 8min-12min to form a sensing structure unit 400 with a first electrode 101 and a second electrode 201. The overall thickness of the sensing structure unit 400 after curing is between 0.2mm and 2.0mm.

[0069] (2) The sensing structure unit 400 is covered with a flexible insulating material to form a flexible insulating layer 500, thus obtaining a complete pressure sensor.

[0070] Example 1

[0071] The raw materials and performance parameters used in this embodiment are as follows:

[0072] Flexible polymer matrix: liquid silicone, TYL6120 / 40 from Shenzhen Xin'an Tianyu Organosilicon Co., Ltd., viscosity <6500mPa·s;

[0073] Nano-conductive filler: conductive carbon black, with a diameter of 100 nm;

[0074] Flexible conductive fiber wire: silver-plated polyester fiber wire, with a diameter of 0.03mm and a resistance of 0.5Ω / m;

[0075] Flexible non-conductive fiber yarn: polyester fiber yarn, with a diameter of 0.03mm;

[0076] Silane coupling agent: KH560;

[0077] Silicone adhesive: KN-300B from Conlibon.

[0078] A method for manufacturing a pressure sensor includes the following steps:

[0079] (1) Preparation of flexible conductive fibers: Liquid silicone and conductive carbon black were mixed at a mass ratio of 100:6.2. After degassing, an uncured flexible conductive polymer composite material was obtained. Silver-plated polyester fiber threads were plasma-treated at 45°C using an RF plasma cleaner. After spraying with silane coupling agent KH560, the fibers were immersed in the flexible conductive polymer composite material. After removing the excess flexible conductive polymer composite material, the fibers were cured at 120°C for 10 min. The resistivity after curing was 8.537 × 10⁻⁶. 6 KΩ·mm, forming a silver-plated polyester fiber thread with an outer layer of flexible conductive polymer composite material; then repeated impregnation and curing to obtain;

[0080] (2) Preparation of flexible non-conductive fiber: Flexible polyester fiber yarn is processed using the same preparation method as in step (1) to obtain;

[0081] (3) Fabrication of sensing structural units: The flexible conductive fiber obtained in step (1) and the flexible non-conductive fiber obtained in step (2) are combined according to... Figure 2-5 The structure shown is woven into a textile fabric structure with a thickness of 0.10 mm; then, an uncured flexible conductive polymer composite material obtained in step (1) is coated on both sides of the textile fabric structure. After curing at 120°C for 10 min, a sensing structure unit 400 with a thickness of 0.3 mm is formed; wherein the first interdigital part 102 and the second interdigital part 202 are distributed in the textile fabric structure, and the first electrode 101 and the second electrode 201 are reserved as the positive and negative electrodes of the pressure sensor.

[0082] (4) Preparation of pressure sensor: Apply silicone adhesive to the upper and lower surfaces of the sensing structure unit 400 obtained in step (4), then bond a 1.0 mm thick silicone film, and cure at room temperature for 6 hours to obtain a complete pressure sensor.

[0083] The working principle of the pressure sensor of the present invention is as follows: when the sensing structure unit receives pressure transmitted from the surface, it deforms, causing the spacing of the nano-conductive fillers inside the flexible conductive polymer composite material covered by the flexible conductive fiber to change. This, in turn, causes a change in the conductive network structure of the textile fabric constructed by the flexible conductive fiber. Since the conductive network adopts an interdigitated electrode structure, it increases the sensitivity to changes in resistance, ultimately causing a change in the resistance signal between the electrodes. Then, the force on the sensor at this time can be deduced from the piezoresistive characteristic curve of the pressure sensor.

[0084] Performance testing

[0085] Under cyclic pressure conditions of 0N-100N, the pressure sensor prepared in Example 1 (according to...) Figure 2 The structure shown is a woven textile fabric structure. Cyclic loading is applied, and the real-time resistance value R of the pressure sensor is compared with the initial resistance value R0 of the pressure sensor to obtain the resistance change R0 / R of the pressure sensor during the force application process. Figure 7 As shown. From Figure 7 The results show that the pressure sensor's resistance change response time is less than 0.1s, the resistance signal transformation coefficient R0 / R reaches 36, and the electrical signal output is stable after multiple cyclic loadings without signal drift. This indicates that the pressure sensor prepared by this invention has a fast response speed, high sensitivity, and stable output signal.

[0086] For those skilled in the art, several simple deductions or substitutions can be made without departing from the inventive concept, without requiring creative effort. Therefore, any simple improvements made to this invention by those skilled in the art based on the disclosure of this invention should be within the scope of protection of this invention. The above embodiments are preferred embodiments of this invention, and all processes similar to this invention and equivalent changes should fall within the scope of protection of this invention.

Claims

1. A pressure sensor, characterized in that, include: The sensing structure unit includes a first interdigital electrode and a second interdigital electrode. The fingers of the first interdigital electrode and the fingers of the second interdigital electrode are parallel to each other and are formed into a textile fabric structure by cross-weaving flexible non-conductive fibers; or the fingers of the first interdigital electrode and the fingers of the second interdigital electrode are orthogonally arranged and cross-weaved to form a textile fabric structure; both the first interdigital electrode and the second interdigital electrode are made of flexible conductive fibers; both sides of the textile fabric structure are coated with a flexible conductive polymer composite material. A flexible insulating layer that covers the sensing structure unit.

2. The pressure sensor according to claim 1, characterized in that, The raw material components of the flexible conductive polymer composite material include, by weight: 100 parts of flexible polymer matrix and 4-8 parts of nano-conductive filler.

3. The pressure sensor according to claim 2, characterized in that, The elongation at break of the flexible polymer matrix is ​​20-500%; the flexible polymer matrix is ​​selected from any one of polydimethylsiloxane, two-component liquid silica gel, two-component polyurethane, and two-component polyurethane elastomer; the nano-conductive filler is selected from at least one of nano-superconducting carbon black, nano-conductive multi-walled carbon nanotubes, and conductive graphene.

4. The pressure sensor according to claim 2 or 3, characterized in that, The flexible conductive fiber includes a flexible conductive fiber thread and a flexible conductive polymer composite material, wherein the flexible conductive polymer composite material covers the flexible conductive fiber thread; the flexible conductive fiber thread is made of a conductive polymer fiber or a non-conductive polymer fiber with a conductive metal plated on its surface.

5. The pressure sensor according to claim 4, characterized in that, The conductive polymer fiber is selected from at least one of polyaniline, polythiophene, polyacetylene, and polypyrrole; the conductive metal is selected from at least one of silver, copper, nickel, and zinc; and the non-conductive polymer fiber is selected from at least one of nylon, polyester, and spandex.

6. The pressure sensor according to claim 2 or 3, characterized in that, The flexible non-conductive fiber includes a flexible non-conductive fiber thread and the flexible conductive polymer composite material, wherein the flexible conductive polymer composite material covers the flexible non-conductive fiber thread; the flexible non-conductive fiber thread is made of non-conductive polymer fiber.

7. The pressure sensor according to claim 6, characterized in that, The non-conductive polymer fiber is selected from at least one of nylon, polyester, spandex, and silk fiber.

8. The pressure sensor according to claim 1, characterized in that, The flexible insulating layer is made of any one of silicone, polyethylene terephthalate, or polyimide.

9. A method for manufacturing a pressure sensor as described in any one of claims 1 to 8, characterized in that, Includes the following steps: (1) The first interdigital electrode and the second interdigital electrode made of flexible conductive fiber are woven into a textile fabric structure; or the first interdigital electrode and the second interdigital electrode are woven into a textile fabric structure by flexible non-conductive fiber; and then a flexible conductive polymer composite material is coated on both sides of the textile fabric structure, and after curing, a sensing structure unit with dual wires is formed. (2) The sensing structure unit is covered with a flexible insulating material to form a flexible insulating layer, thereby obtaining the pressure sensor.

10. The method for preparing a pressure sensor according to claim 9, characterized in that, The preparation process of the flexible conductive fiber is as follows: a flexible polymer matrix, nano-conductive filler and curing agent are mixed in a mass ratio, and after degassing treatment, an uncured flexible conductive polymer composite material is obtained; the flexible conductive fiber thread is hydroxylated, coated with silane coupling agent, and then immersed in the flexible conductive polymer composite material. After being taken out, it is cured to form a flexible conductive fiber thread with an outer layer of flexible conductive polymer composite material; the process of repeated immersion and curing is then repeated to obtain the flexible conductive fiber. The preparation process of the flexible non-conductive fiber is as follows: the flexible non-conductive fiber thread is processed using the same preparation method as the flexible conductive fiber.

Images