Preparation method of sewing type fabric pressure sensor

Abstract

The invention discloses a preparation method of a sewing-in type fabric pressure sensor, the sewing-in type fabric pressure sensor is composed of conductive yarns and warp-knitted spacer fabrics, the preparation method comprises the following steps: S1, using a polyvinyl alcohol solution to dip-coat and dry the yarns; s2, adsorbing carbon nanotubes on the yarn coated with polyvinyl alcohol obtained in the step S1, and drying to obtain conductive yarn; and S3, sewing the conductive yarns into a warp-knitted spacer fabric to obtain the sewed fabric pressure sensor. The yarn is coated with polyvinyl alcohol, and the loading capacity of the conductive material is improved through the adhesion of the polyvinyl alcohol; the conductive yarn with stable resistance change is obtained by repeatedly adsorbing the carbon nanotubes on the yarn, and then the conductive yarn is sewed into the warp-knitted spacer fabric to obtain the sewed fabric pressure sensor, and the obtained fabric pressure sensor has the characteristics of high sensitivity, wide monitoring range, softness, breathability and the like.

Description

Technical Field

[0001] The invention relates to the field of textile-based flexible sensor preparation technology and processing, and in particular to a method for preparing a sewn-in fabric pressure sensor. Background Art

[0002] As people pay more and more attention to health and quality of life, smart fabrics that can monitor and feedback the body's condition in real time can greatly improve people's quality of life. At present, a large number of people in society have been engaged in desk work for a long time, and diseases such as muscle strain and spinal curvature have become a common disease. Wearable electronic fabrics are used in physical activity monitoring, especially in sitting posture monitoring and correction, which is expected to improve this problem.

[0003] However, the pressure sensors currently prepared have many shortcomings, such as limited monitoring pressure range and complex preparation process. These problems limit their promotion and popularization in practical applications. Therefore, it is particularly important to develop a fabric pressure sensor that can cover a wider pressure range and has a simple preparation process. Summary of the invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defects of the fabric pressure sensor in the prior art, such as small pressure monitoring range, low sensitivity and complicated preparation method, thereby providing a preparation method of a sewn-in fabric pressure sensor.

[0005] The present invention provides a method for preparing a sewn-in fabric pressure sensor, wherein the sewn-in fabric pressure sensor is composed of conductive yarn and warp-knitted spacer fabric, and the preparation method comprises:

[0006] S1: The yarn is dip-coated with a polyvinyl alcohol solution and dried;

[0007] S2: adsorbing carbon nanotubes onto the yarn coated with polyvinyl alcohol obtained in step S1, and drying the yarn to obtain a conductive yarn;

[0008] S3: Sewing the conductive yarn into the warp-knitted spacer fabric to obtain the sewn-in fabric pressure sensor.

[0009] In one embodiment, in the polyvinyl alcohol solution in step S1, the mass fraction of polyvinyl alcohol is 2-10wt%, the temperature of the polyvinyl alcohol solution is 95°C, the immersion time is 5-15min, the drying temperature is 85°C, and the drying time is 15min.

[0010] In one embodiment, in step S2, the method for preparing the conductive yarn includes:

[0011] The yarn treated in step S1 was immersed in a carbon nanotube dispersion at a temperature of 65° C. for 30 min, and the drying temperature was 85° C. for 180 min.

[0012] In one of the embodiments, the carbon nanotube dispersion is prepared by preparing a carbon nanotube aqueous dispersion with a mass fraction of 2-10 wt %, and repeatedly ultrasonicating the carbon nanotube aqueous dispersion in an ultrasonic machine for 6 hours.

[0013] In one embodiment, the type of the yarn includes blended yarn, pure spun yarn or core-spun yarn.

[0014] In one embodiment, the fiber type of the yarn includes one of polyester, spandex, nylon, cotton, polypropylene, wool, and silk.

[0015] In one of the embodiments, the method for sewing the conductive yarn into the warp knitted spacer fabric in step S3 includes: using tools such as a crochet hook, sewing thread, and a sewing machine to penetrate the conductive yarn obtained in step S2 through the upper and lower surfaces of the warp knitted spacer fabric, wherein the thickness of the warp knitted spacer fabric is 10-50 mm, the lower surface of the warp knitted spacer fabric is a plain weave, and the upper surface is a plain weave or a mesh weave, and the fiber material of the warp knitted spacer fabric includes one of nylon, polyester, polypropylene, and vinylon; the conductive yarn is used to connect with the copper conductive wire for signal transmission.

[0016] The technical solution of the present invention has the following advantages:

[0017] The present invention provides a method for preparing a sewn-in fabric pressure sensor, wherein the sewn-in fabric pressure sensor is composed of a conductive yarn and a warp-knitted spacer fabric, and the preparation method comprises: S1: impregnating and coating the yarn with a polyvinyl alcohol solution and drying it; S2: adsorbing carbon nanotubes on the yarn coated with polyvinyl alcohol obtained in step S1, and obtaining the conductive yarn after drying; S3: sewing the conductive yarn into the warp-knitted spacer fabric to obtain the sewn-in fabric pressure sensor. On the one hand, the base material of the sewn-in fabric pressure sensor is a textile material, which has the characteristics of being soft, breathable, and comfortable, thereby improving the comfort and convenience of the wearer. On the other hand, the hydroxyl functional groups rich in polyvinyl alcohol can form hydrogen bonding forces with carbon nanotubes and have good viscosity. Coating polyvinyl alcohol on the yarn can adsorb more carbon nanotubes to form conductive yarn, making the resistance smaller and more stable, thereby improving the detection sensitivity. On the other hand, by combining conductive yarn with warp-knitted spacer fabric, continuous collection of resistance signals under a wide pressure range is achieved, which can be used in smart seat cushions to collect sitting posture signals and provide a solution for a fabric pressure sensor for sitting posture correction. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 The figures are the original yarn and the conductive yarn in Example 1 of the present invention, wherein (A) is the original yarn and (B) is the conductive yarn after treatment;

[0020] Figure 2 Schematic diagram of a sewn-in fabric pressure sensor obtained in Example 1 of the present invention;

[0021] Figure 3 The cross-sectional photograph and scanning electron microscope image of the sewn-in fabric pressure sensor in Example 1 of the present invention;

[0022] Figure 4 This is a comparison diagram of the resistance of the conductive yarns obtained in Example 1, Example 2, Example 3, Example 4 and the comparative example of the present invention;

[0023] Figure 5 This is a scanning electron microscope image of the final yarn in Comparative Example 2 of the present invention;

[0024] Figure 6 This is a scanning electron microscope image of the final yarn after treatment in Example 2 of the present invention;

[0025] Figure 7 is a curve diagram showing the relationship between pressure and resistance of the sewn-in fabric sensor in Example 3 of the present invention;

[0026] Figure 8 is a stability diagram of the resistance of the sewn-in fabric sensor under different pressures in Example 3 of the present invention;

[0027] Fig. 9 This is a cyclic test diagram of the resistance of the sewn-in fabric sensor under different pressures in Example 3 of the present invention;

[0028] Fig.10 The resistance change of the sewn-in fabric sensor combined with the insole in Example 4 of the present invention;

[0029] Fig.11 This is a physical picture of assembling a fabric sensor on a seat cushion to form a 3×3 pressure sensing array in Example 4 of the present invention;

[0030] Fig.12 The sensor resistance distribution of the pressure sensing array in Example 4 of the present invention in a normal sitting position;

[0031] Fig.13 The sensor resistance distribution of the pressure sensing array in Example 4 of the present invention in a reclining sitting position;

[0032] Fig.14 The sensor resistance distribution of the pressure sensing array in Example 4 of the present invention in a forward leaning sitting posture. DETAILED DESCRIPTION

[0033] Example 1

[0034] This embodiment provides a sewn-in fabric pressure sensor, and the specific preparation method thereof is as follows:

[0035] (1) 50 g of polyvinyl alcohol was dissolved in 950 g of deionized water and stirred at 95° C. for 4 hours to prepare a polyvinyl alcohol solution with a mass percentage of 5%.

[0036] (2) Select polyester-wrapped spandex yarn as the elastic yarn, immerse the polyester-wrapped spandex yarn in the polyvinyl alcohol solution prepared in step (1) for 10 minutes, and maintain the temperature of the polyvinyl alcohol solution at 95°C.

[0037] (3) Take out the polyester-wrapped spandex yarn treated with polyvinyl alcohol in step (2), and dry it in an oven at a constant temperature of 85° C. for 15 minutes.

[0038] (4) 20 g of carbon nanotubes were added to 980 g of water, and the water was ultrasonicated repeatedly for 6 hours in an ultrasonic machine to prepare a carbon nanotube dispersion with a mass percentage of 2%.

[0039] (5) Immerse the polyester-wrapped spandex yarn treated with polyvinyl alcohol obtained in step (3) in the carbon nanotube dispersion obtained in step (4), and control the temperature of the immersion bath to be 65° C. for 30 minutes.

[0040] (6) Take out the polyester-covered spandex yarn treated with the carbon nanotube dispersion in step (5), and dry it in an environment of 85° C. for 180 min to obtain a conductive yarn. Figure 1 As shown in the figure, after being treated with carbon nanotube dispersion, the original white yarn turned black, and there were no uneven black spots, indicating the uniform distribution of the conductive material. This is because the abundant hydroxyl functional groups in polyvinyl alcohol can form hydrogen bonds with carbon nanotubes and have good viscosity. Coating polyvinyl alcohol on the yarn can absorb more carbon nanotubes to form conductive yarn, making the conductive material evenly distributed.

[0041] (7) The conductive yarn obtained in step (6) is sewed into the warp-knitted spacer fabric by crochet, and the upper and lower ends are connected by copper conductive wire to obtain a sewn-in fabric pressure sensor.

[0042] like Figure 2 As shown, black conductive yarn passes through the upper and lower surfaces of the warp-knitted spacer fabric and is sewn into the fabric to form a fabric pressure sensor. In addition, Figure 3 This is also proved by the physical picture and scanning electron microscope picture of the cross section of the pressure sensor. The black conductive yarn is thicker than the spacer yarn of the warp knitted spacer fabric, and runs through the upper and lower surfaces of the fabric, and remains stably in the middle of the warp knitted spacer fabric.

[0043] Example 2

[0044] This embodiment provides a sewn-in fabric pressure sensor, and the specific preparation method thereof is as follows:

[0045] (1) 50 g of polyvinyl alcohol was dissolved in 950 g of deionized water and stirred at 95° C. for 4 hours to prepare a polyvinyl alcohol solution with a mass percentage of 5%.

[0046] (2) Select polyester-wrapped spandex yarn as the elastic yarn, immerse the polyester-wrapped spandex yarn in the polyvinyl alcohol solution prepared in step (1) for 10 minutes, and maintain the temperature of the polyvinyl alcohol solution at 95°C.

[0047] (3) Take out the polyester-wrapped spandex yarn treated with polyvinyl alcohol in step (2), and dry it in an oven at a constant temperature of 85° C. for 15 minutes.

[0048] (4) 40 g of carbon nanotubes were added into 960 g of water and ultrasonicated repeatedly for 6 hours in an ultrasonic machine to prepare a carbon nanotube dispersion with a mass fraction of 4%.

[0049] (5) Immerse the polyester-wrapped spandex yarn treated with polyvinyl alcohol obtained in step (3) in the carbon nanotube dispersion obtained in step (4), and control the temperature of the immersion bath to be 65° C. for 30 minutes.

[0050] (6) Taking out the polyester-wrapped spandex yarn treated with the carbon nanotube dispersion in step (5), and drying it in an environment of 85° C. for 180 min to obtain a conductive yarn.

[0051] (7) The conductive yarn obtained in step (6) is sewed into the warp-knitted spacer fabric by crochet, and the upper and lower ends are connected by copper conductive wire to obtain a sewn-in fabric pressure sensor.

[0052] Example 3

[0053] This embodiment provides a sewn-in fabric pressure sensor, and the specific preparation method thereof is as follows:

[0054] (1) 50 g of polyvinyl alcohol was dissolved in 950 g of deionized water and stirred at 95° C. for 4 hours to prepare a polyvinyl alcohol solution with a mass percentage of 5%.

[0055] (2) Select polyester-wrapped spandex yarn as the elastic yarn, immerse the polyester-wrapped spandex yarn in the polyvinyl alcohol solution prepared in step (1) for 10 minutes, and maintain the temperature of the polyvinyl alcohol solution at 95°C.

[0056] (3) Take out the polyester-wrapped spandex yarn treated with polyvinyl alcohol in step (2), and dry it in an oven at a constant temperature of 85° C. for 15 minutes.

[0057] (4) 60 g of carbon nanotubes were added into 940 g of water and ultrasonicated repeatedly for 6 hours in an ultrasonic machine to prepare a carbon nanotube dispersion with a mass fraction of 6%.

[0058] (5) Immerse the polyester-wrapped spandex yarn treated with polyvinyl alcohol obtained in step (3) in the carbon nanotube dispersion obtained in step (4), and control the temperature of the immersion bath to be 65° C. for 30 minutes.

[0059] (6) Taking out the polyester-wrapped spandex yarn treated with the carbon nanotube dispersion in step (5), and drying it in an environment of 85° C. for 180 min to obtain a conductive yarn.

[0060] (7) The conductive yarn obtained in step (6) is sewed into the warp-knitted spacer fabric by crochet, and the upper and lower ends are connected by copper conductive wire to obtain a sewn-in fabric pressure sensor.

[0061] Example 4

[0062] This embodiment provides a sewn-in fabric pressure sensor, and the specific preparation method thereof is as follows:

[0063] (1) 50 g of polyvinyl alcohol was dissolved in 950 g of deionized water and stirred at 95° C. for 4 hours to prepare a polyvinyl alcohol solution with a mass percentage of 5%.

[0064] (2) Select polyester-wrapped spandex yarn as the elastic yarn, immerse the polyester-wrapped spandex yarn in the polyvinyl alcohol solution prepared in step (1) for 10 minutes, and maintain the temperature of the polyvinyl alcohol solution at 95°C.

[0065] (3) Take out the polyester-wrapped spandex yarn treated with polyvinyl alcohol in step (2), and dry it in an oven at a constant temperature of 85° C. for 15 minutes.

[0066] (4) 80 g of carbon nanotubes were added into 920 g of water and ultrasonicated repeatedly for 6 hours in an ultrasonic machine to prepare a carbon nanotube dispersion with a mass fraction of 8%.

[0067] (5) Immerse the polyester-wrapped spandex yarn treated with polyvinyl alcohol obtained in step (3) in the carbon nanotube dispersion obtained in step (4), and control the temperature of the immersion bath to be 65° C. for 30 minutes.

[0068] (6) Taking out the polyester-wrapped spandex yarn treated with the carbon nanotube dispersion in step (5), and drying it in an environment of 85° C. for 180 min to obtain a conductive yarn.

[0069] (7) The conductive yarn obtained in step (6) is sewed into the warp-knitted spacer fabric by crochet, and the upper and lower ends are connected by copper conductive wire to obtain a sewn-in fabric pressure sensor.

[0070] Comparative Example 1

[0071] This comparative example provides a yarn, which is different from Example 1 only in that it is not treated with polyvinyl alcohol. The specific preparation method is as follows:

[0072] (1) 20 g of carbon nanotubes were added to 980 g of water and ultrasonicated repeatedly for 6 hours in an ultrasonic machine to prepare a carbon nanotube dispersion with a mass percentage of 2%.

[0073] (2) Immerse the polyester-wrapped spandex yarn in the carbon nanotube dispersion prepared in step (1), and control the immersion bath to be stable at 65° C. for 30 minutes.

[0074] (3) Taking out the polyester-wrapped spandex yarn treated with the carbon nanotube dispersion in step (2), and drying it in an environment of 85° C. for 180 min to obtain a conductive yarn.

[0075] (4) The conductive yarn obtained in step (3) is sewed into the warp-knitted spacer fabric by crochet, and the upper and lower ends are connected by copper conductive wire to obtain a sewn-in fabric pressure sensor.

[0076] The conductive materials obtained in Example 1, Example 2, Example 3, Example 4 and Comparative Example 1 were cut into 10 cm lengths, and a digital ammeter (Kethley 2450) was used to record the resistance of the conductive yarn, and the yarn resistance per unit length was analyzed and calculated. Figure 4 It can be seen that as the concentration of the carbon nanotube dispersion increases from 2wt% to 8wt%, the resistance of the conductive yarn gradually decreases from 17.5kΩ / cm to 3.3kΩ / cm, and it has good conductivity, so the sensor is more sensitive. However, since the comparative example 1 was not treated with polyvinyl alcohol solution, the yarn resistance of 69.2kΩ / cm was significantly greater than that of Example 1. This is because the abundant hydroxyl functional groups in polyvinyl alcohol can form hydrogen bonds with carbon nanotubes and have good viscosity. With the auxiliary effect of polyvinyl alcohol, more carbon nanotubes can be adsorbed to form a conductive layer, so the resistance is smaller.

[0077] Comparative Example 2

[0078] This comparative example provides a yarn, which is different from Example 2 only in that it is not treated with carbon nanotubes. The specific preparation method is as follows:

[0079] (1) 50 g of polyvinyl alcohol was dissolved in 950 g of deionized water and stirred at 95° C. for 4 hours to prepare a polyvinyl alcohol solution with a mass percentage of 5%.

[0080] (2) Select polyester-wrapped spandex yarn as the elastic yarn, immerse the polyester-wrapped spandex yarn in the polyvinyl alcohol solution prepared in step (1) for 10 minutes, and maintain the temperature of the polyvinyl alcohol solution at 95°C.

[0081] (3) Take out the polyester-wrapped spandex yarn treated with polyvinyl alcohol in step (2), and dry it in an oven at a constant temperature of 85° C. for 15 minutes.

[0082] (4) The yarn obtained in step (3) is sewed into a warp-knitted spacer fabric by crochet, and the upper and lower ends are connected by copper conductive wire to obtain a sewn-in fabric pressure sensor.

[0083] Figure 5 The photograph of the comparative 2 yarn under a scanning electron microscope shows that the fibers in the yarn are bonded with polyvinyl alcohol to form a good combination, but there is no conductive material and no conductive path can be formed. Figure 6 This is a scanning electron microscope photograph of the yarn of Example 2. Compared with Comparative Example 2, the surfaces of the fibers and yarns are covered with carbon nanotube conductive materials, forming a good conductive path and having the capability of a strain sensor.

[0084] Test Example 1

[0085] This test is a basic sensor performance test of the sensor:

[0086] (1) Test of the relationship between resistance and pressure of fabric pressure sensor: The fabric pressure sensor sewn into the fabric in Example 3 was placed in a compression and tension tester (ALJ-50HB), and the pressure test was performed at a speed of 0.1 mm / s. The resistance and pressure values ​​of the fabric sensor during this process were recorded by a digital meter (Kethley2450). The relationship between the relative resistance change of the fabric pressure sensor and the pressure was obtained by calculation and analysis. Figure 7 As shown in the figure, as the pressure increases, the resistance of the sensor decreases. The greater the pressure, the greater the decrease in resistance. Under a pressure of 30 kPa, the relative resistance change is about -42%. The obvious resistance response change has the potential to be applied to smart cushions to monitor pressure changes.

[0087] (2) Fabric pressure sensor resistance stability test: The sewn-in fabric pressure sensor in Example 3 was placed in a tensile tester (ALJ-50HB), the compression degree was adjusted, the applied pressure was controlled and maintained for 2.5 seconds, and the resistance and pressure values ​​of the fabric sensor during this process were recorded by a digital meter (Kethley 2450) to evaluate the stability of the sensor. Figure 8 As shown, the fabric pressure sensor obtained by this method can maintain stable resistance under continuous pressure without obvious fluctuations, and can still have good sensing stability even under a high pressure of 120 kPa.

[0088] (3) Fabric pressure sensor resistance cycle test: The sewn-in fabric pressure sensor in Example 3 was placed in a tensile tester (ALJ-50HB), the compression degree was adjusted, the applied pressure was controlled, and a compression-recovery cycle test was performed. The resistance and pressure values ​​of the fabric sensor during this process were recorded by a digital meter (Kethley 2450) to evaluate the cyclic stability of the sensor. Fig. 9 As shown, the fabric pressure sensor obtained by this method can still maintain a good resistance response in multiple repeated cyclic compression-recovery tests, and the repetitive and regular resistance change curve proves that the fabric pressure sensor obtained by this method has the ability to be actually applied to activity monitoring.

[0089] Test Example 2

[0090] This test case is a test of actual human activity monitoring using a fabric sensor:

[0091] (1) Insole compression test: The sewn-in fabric sensor obtained in Example 4 was connected to the copper conductive wire electrode and further bonded to the insole to monitor and evaluate the human body's walking posture and compression activity. The resistance change in this process was measured using a digital multimeter (Kethley 2450). The results are as follows: Fig.10 As shown, during the continuous walking posture, the fabric pressure sensor accurately collects the walking motion signal. Further analysis shows that the step frequency is about one step per second, achieving healthy management of human movement.

[0092] (2) Sitting posture pressure distribution monitoring test: The 9 sewn-in fabric pressure sensors obtained in Example 4 were used to form a 3×3 pressure sensor array, and the sensor array was bonded to the seat cushion. Furthermore, volunteers sat on the sensor array in different sitting postures, and the resistance change of each sensor was recorded by a separate digital multimeter (VC9803A). Fig.11 The figure shows a 3×3 fabric pressure sensor array combined with a seat cushion. The X and Y directions are defined respectively to form the array coordinate axis. Fig.12 , Fig.13 , Fig.14The resistance change distribution diagram collected by the sensor array for volunteers in standard, backward and forward sitting positions. As can be seen from the figure, the sensor array accurately collects the pressure distribution in different sitting positions. The center of the body changes in different sitting positions, causing the pressure distribution to change with different sitting positions. Fig.12 As shown in the figure, in a standard sitting position, the pressure gradually increases from the thigh to the buttocks. Fig.13 As shown in FIG. 1 , in the backward posture, the pressure change is roughly opposite to that in the forward posture, and the pressure in the rear part increases significantly. Fig.14 As shown in the figure, in the forward sitting posture, the pressure on both sides of the thighs is more significant than that in the standard sitting posture, while the pressure on the buttocks is reduced. Therefore, the smart cushion for long-term sitting alarm and posture correction can be used to treat bedsores, hunchbacks, myopia and other diseases.

[0093] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the present invention.

Claims

1. A method for preparing a sewn-in fabric pressure sensor, characterized in that: The sewn-in fabric pressure sensor is composed of conductive yarn and warp-knitted spacer fabric, and the preparation method comprises: S1: The yarn is dip-coated with a polyvinyl alcohol solution and dried; S2: adsorbing carbon nanotubes onto the yarn coated with polyvinyl alcohol obtained in step S1, and drying the yarn to obtain a conductive yarn; S3: Sewing the conductive yarn into the warp-knitted spacer fabric to obtain the sewn-in fabric pressure sensor.

2. The preparation method according to claim 1, characterized in that: In the polyvinyl alcohol solution in step S1, the mass fraction of polyvinyl alcohol is 2-10wt%, the temperature of the polyvinyl alcohol solution is 95°C, the immersion time is 5-15min, the drying temperature is 85°C, and the drying time is 15min.

3. The preparation method according to claim 1, characterized in that: In step S2, the method for preparing the conductive yarn comprises: The yarn treated in step S1 was immersed in a carbon nanotube dispersion at a temperature of 65° C. for 30 min, and the drying temperature was 85° C. for 180 min.

4. The preparation method according to claim 3, characterized in that: The preparation method of the carbon nanotube dispersion is as follows: preparing a carbon nanotube aqueous dispersion with a mass fraction of 2-10 wt %, and repeatedly ultrasonicating the carbon nanotube aqueous dispersion in an ultrasonic machine for 6 hours.

5. The preparation method according to claim 1, characterized in that: The types of the yarn include blended yarn, pure spun yarn or core-spun yarn.

6. The preparation method according to claim 1, characterized in that: The fiber type of the yarn includes one of polyester, spandex, nylon, cotton, polypropylene, wool and silk.

7. The preparation method according to claim 1, characterized in that: The method for sewing the conductive yarn into the warp knitted spacer fabric in step S3 includes: using tools such as a crochet hook, sewing thread, and a sewing machine to penetrate the conductive yarn obtained in step S2 through the upper and lower surfaces of the warp knitted spacer fabric, wherein the thickness of the warp knitted spacer fabric is 10-50 mm, the lower surface of the warp knitted spacer fabric is a plain weave, and the upper surface is a plain weave or a mesh weave, and the fiber material of the warp knitted spacer fabric includes one of nylon, polyester, polypropylene, and vinylon; the conductive yarn is used to connect with the copper conductive wire for signal transmission.

Images