Preparation method of high-density ultra-thin flexible pressure sensor array and sensor

Abstract

The application provides a high-density ultrathin flexible pressure sensor array preparation method, which comprises the following steps: preparing a porous conductive colloid with a porous structure and uniformly distributed conductive particles, wherein the components of the porous conductive colloid are carbon nanotubes and polydimethylsiloxane; using double-sided thermal release tape and water-based adhesive tape to fix a metal foil flat on a glass sheet; performing laser cutting on the metal foil to prepare an array metal electrode; using an adhesive to respectively fix the array metal electrode on the top surface and the bottom surface of the porous conductive colloid by adhesion, so that the array metal electrode is crossed in the direction of the top surface and the bottom surface and forms a 90-degree angle; dissolving the water-based adhesive tape by water flow, and then drying to obtain a high-density ultrathin flexible pressure sensor array. The application can solve the technical problem that a large-area flexible pressure sensor for wearable medical electronic products cannot simultaneously consider high sensitivity and a wide pressure detection range.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of flexible electronic components, and particularly relates to a high-density ultra-thin flexible pressure sensor array preparation method and a sensor. BACKGROUND

[0002] As a data source of the Internet of Things, wearable medical electronics can capture physiological or behavioral characteristics of the human body in real time, and is expected to change the traditional medical service system centered on disease into a personalized medical model focused on disease prevention, and is the key to realizing smart medical care. Among them, the piezoresistive flexible pressure sensor, due to its low energy consumption, high sensitivity, simple process flow, low manufacturing cost, large-scale manufacturing, easy integration and other advantages, can be applied to health monitoring, disease diagnosis, precision surgery and other medical services, and is highly concerned in the next generation of wearable medical electronics.

[0003] At present, for some integrated nursing and monitoring clothes, a large-area flexible pressure sensor is needed, but the structure and material properties of the flexible pressure sensor in the prior art will be affected once the area is enlarged, and a complex electrode layout and connection mode are needed, so that high sensitivity and wide pressure detection range cannot be considered; and the larger the flexible sensor filled into the clothes, the heavier the weight of the clothes, and the more inconvenient to wear. SUMMARY

[0004] In view of the deficiencies in the prior art, the present application proposes a high-density ultra-thin flexible pressure sensor array preparation method and a sensor to solve the technical problem that the large-area flexible pressure sensor for wearable medical electronic products in the prior art cannot consider high sensitivity and wide pressure detection range.

[0005] The technical scheme adopted by the present application is as follows:

[0006] A high-density ultra-thin flexible pressure sensor array preparation method, comprising:

[0007] Preparation of a porous conductive colloid with a porous structure and uniform distribution of conductive particles, the components of the porous conductive colloid being carbon nanotubes and polydimethylsiloxane; using double-sided heat release tape and water-based adhesive tape to fix the metal foil flat on the glass sheet, laser cutting the metal foil to prepare an array of metal electrodes; using an adhesive to respectively fix the array of metal electrodes on the top surface and the bottom surface of the porous conductive colloid, so that the array of metal electrodes is crossed in the direction of the top surface and the bottom surface, and forms a 90-degree angle; dissolving the water-based adhesive tape by water flow, and then drying to obtain a high-density ultra-thin flexible pressure sensor array.

[0008] Further, the preparation of a porous conductive colloid with a porous structure and uniform distribution of conductive particles comprises:

[0009] Preparation of carbon nanotube and polydimethylsiloxane mixture; sequentially add curing agent, salt particles after evaporation crystallization grinding to the mixture, stirring to obtain the first mixture; heating and curing the first mixture, after cooling the cured first mixture, soaking in water to dissolve and remove the salt particles in the mixture to obtain the second mixture; drying the second mixture to obtain a porous conductive colloid with a porous structure and uniformly distributed conductive particles.

[0010] Further, the mass ratio of carbon nanotube and polydimethylsiloxane is 1:30-1:40, and the particle size of the salt is 100 mesh.

[0011] Further, the first mixture is heated and cured using a mold, and the thickness of the cured first mixture is controlled by setting the depth of the mold recess.

[0012] Further, the metal foil is a copper foil, and the thickness of the copper foil is 5 microns.

[0013] Further, the adhesive is a composite adhesive containing Ecoflex and carbon nanotubes.

[0014] In a second aspect, a high-density ultra-thin flexible pressure sensor array is provided, which is prepared by the preparation method of the high-density ultra-thin flexible pressure sensor array of the first aspect.

[0015] In a third aspect, another preparation method of a high-density ultra-thin flexible pressure sensor array is provided, which includes: preparing a porous conductive colloid with a porous structure and uniformly distributed conductive particles, the components of the porous conductive colloid being carbon nanotubes and polydimethylsiloxane; using an adhesive to fix a metal foil on the top surface and the bottom surface of the porous conductive colloid respectively; using a laser to cut the metal foil, so that the top surface metal electrode and the bottom surface metal electrode of the cut porous conductive colloid are crossed and have a 90-degree angle; removing the excess metal foil between the array electrodes and the cut metal foil to obtain a high-density ultra-thin flexible pressure sensor array.

[0016] Further, the laser is an ultraviolet laser, the cutting speed of the ultraviolet laser cutting machine is set to 300, the cutting power is set to 30%, and the cutting frequency is 26 times.

[0017] In a fourth aspect, a high-density ultra-thin flexible pressure sensor array is provided, which is prepared by the preparation method of the high-density ultra-thin flexible pressure sensor array of the third aspect.

[0018] From the above technical solutions, the beneficial technical effects of the present application are as follows:

[0019] 1. The area can be adjusted to more than square meter level by adjusting the length and width of the mold frame, and the weight is light. It has the advantages of high precision measurement, wide measurement range, high stability and fast response; at the same time, the electrodes are arranged in high-density array form, which can measure the pressure distribution of multiple points at the same time, and realize low-cost pressure measurement.

[0020] 2. The whole preparation process is simple and convenient to switch processes, and the order of transferring metal foil and laser cutting metal foil can be adjusted. The copper foil after transfer is directly cut, which can make the electrode unit of the sensor cross more accurately, and the crosstalk is smaller during pressure imaging test. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the specific embodiments or prior art description will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, each element or part is not necessarily drawn according to the actual proportion.

[0022] Figure 1 It is the physical diagram of the ultra-thin pressure sensor array of embodiment 1 of the present application;

[0023] Figure 2 It is the sensitivity curve diagram of the ultra-thin pressure sensor array of embodiment 1 of the present application;

[0024] Figure 3 It is the periodic curve diagram of the ultra-thin pressure sensor array of embodiment 1 of the present application under the pressure of 30kPa, 45kPa, 60kPa, 75kPa and 90kPa;

[0025] Figure 4 It is the minimum response pressure diagram of the ultra-thin pressure sensor array of embodiment 1 of the present application;

[0026] Figure 5 It is the response time of the ultra-thin pressure sensor array of embodiment 1 of the present application. DETAILED DESCRIPTION

[0027] The embodiments of the technical solutions of the present application will be described in detail below with reference to the drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present application, and therefore only serve as examples, but cannot limit the protection scope of the present application.

[0028] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in this application should be understood as the usual meaning understood by the skilled person in the field to which the present application belongs.

[0029] Embodiment 1

[0030] The inventors have found that if the area of the flexible sensor is to be increased in an application scenario, more signal transmission paths and contact resistances can be introduced in the process of increasing the area, which can interfere with the effective conduction of the pressure signal, thereby reducing the sensitivity of the sensor. For example, in a large-area capacitive flexible sensor, as the area increases, the distance between the electrodes and the electric field distribution become more difficult to control, making the response of the capacitance change to the pressure change complex, thereby affecting the sensitivity. In terms of material properties, when a wide pressure detection range is to be achieved, the material needs to have appropriate elastic modulus and compressibility. However, in the case of increasing the area, it is difficult to maintain uniform properties of the entire large-area material. For example, for a piezoresistive flexible sensor, it is difficult to ensure that the conductive material and the substrate material of a large area can produce consistent resistance changes under pressure to balance high sensitivity and wide pressure range. In addition, the manufacturing process also faces challenges in the production of large-area flexible sensors. In the large-area manufacturing process, it is difficult to ensure the uniformity and thickness consistency of the material, and these process defects can also result in the sensor being unable to balance high sensitivity and wide pressure detection range.

[0031] In combination with the above research results, the present embodiment provides a preparation method of a high-density ultra-thin flexible pressure sensor array, comprising the following steps:

[0032] Step S1, preparing a porous conductive colloid with a porous structure and uniform distribution of conductive particles, the components of the porous conductive colloid being carbon nanotubes and polydimethylsiloxane

[0033] Step S1 comprises the following sub-steps:

[0034] Step S11, preparing a mixed solution of carbon nanotubes and polydimethylsiloxane

[0035] In a specific embodiment, the mass ratio of carbon nanotubes to polydimethylsiloxane is 1:30-1:40. For example, 0.15g of carbon nanotubes is poured into 5g of PDMS (polydimethylsiloxane) main agent, stirred for 5min, and then ultrasonically oscillated for 1h to obtain a mixed solution of carbon nanotubes and polydimethylsiloxane.

[0036] Step S12, adding a curing agent and salt particles obtained by evaporation crystallization and grinding to the mixed solution in sequence, and stirring to obtain a first mixture

[0037] In a specific embodiment, 0.5g of PDMS curing agent is added to the mixed solution prepared in step 1, and stirred for 1min; then 15g of salt particles obtained by evaporation crystallization and grinding are added, and stirred for 10min until no un-mixed salt particles are visible, to obtain a first mixture.

[0038] The salt particles after evaporation crystallization are prepared by the following method: 200ml water is added to an evaporation dish, and the salt is slowly added to prepare a saturated solution; then the evaporation crystallization is heated on a heating table at 350°C to obtain crystalline salt; and the crystalline salt is poured into a mortar a few times to prepare fine salt particles. Preferably, the particle size of the salt is 100 mesh.

[0039] Step S13, the first mixture is heated and solidified, and after the solidified first mixture is cooled, it is soaked in water to dissolve and remove the salt particles in the mixture to obtain a second mixture

[0040] In a specific embodiment, the first mixture is heated and solidified by means of a mold, and the thickness of the solidified first mixture is controlled by setting the depth of the recess of the mold. Preferably, the mold is a square frame with a bottom plate, and the recess depth is 0.5-0.8mm.

[0041] The first mixture is poured into the mold and the surface is flattened, and then the mold is placed on a heating table with a temperature setting of 130-150°C for 10 minutes for heat treatment. After waiting for the first mixture to solidify, it is removed from the mold and naturally cooled at room temperature. After the solidified first mixture is cooled, it is soaked in pure water for 24 hours to dissolve and remove the salt particles in the first mixture to obtain a second mixture. The reason for removing the salt particles is that the carbon nanotube and polydimethylsiloxane mixture containing the salt particles do not adhere well to the metal electrode.

[0042] Step S14, the second mixture is dried to obtain a porous conductive gel with a porous structure and uniformly distributed conductive particles

[0043] In a specific embodiment, the second mixture is placed in a 60°C oven to dry the moisture to obtain a porous conductive gel with a porous structure and uniformly distributed conductive particles, and the porous conductive gel is a whole square block.

[0044] In this step, the porous conductive gel is made by customizing the mold, and the depth of the recess of the mold is changed to control the thickness while ensuring good performance of the porous conductive gel, so as to control the weight of the entire flexible sensor while ensuring the sensitivity of the sensor. This process has the advantages of strong controllability of the preparation process, high material utilization rate, short preparation period, high efficiency, wide application range, etc., and can perform multiple repeated experiments in a short time.

[0045] Step S2, the metal foil is flatly fixed on the glass sheet using double-sided thermal release tape and water-based adhesive tape, and the metal foil is laser cut to prepare an array of metal electrodes

[0046] In a specific embodiment, the metal foil is selected as a copper (Cu) foil, and the thickness is preferably 5 pm. The copper foil is cut to a suitable size according to the processing requirements, and then a double-sided thermal release tape, a water-based adhesive tape, and a copper foil are sequentially adhered to the surface of the glass sheet from bottom to top. In this way, the copper foil / water-based adhesive tape composite material is fixed on the glass sheet through the double-sided thermal release tape. The gap between the copper foil, the water-based adhesive tape, and the glass sheet is removed by pressing to prevent the surface from being raised, which affects the quality of subsequent laser cutting.

[0047] The ultraviolet laser can irradiate the material surface with a high-density and high-energy laser beam to break the molecular bonds of the material and form a cut. At the same time, the ultraviolet laser is a cold processing form. The laser emitter emits high-energy ultraviolet photons onto the material surface, directly breaking the molecular bonds of the material surface, without generating high heat, and is suitable for preparing high-density electrode arrays.

[0048] In a specific embodiment, the high-density array design is imported through the laser marking software. The cutting speed of the ultraviolet laser cutting machine is 300, the cutting power is 35%, and the cutting frequency is 22 times. The red light contour is turned on, and the copper foil is aligned for cutting. The cutting effect is that the laser only cuts the surface copper foil of the copper foil / water-based adhesive tape composite material, and does not cut the underlying water-based adhesive tape. Then, using a tool, such as tweezers, the excess copper foil between the array electrodes is slowly clamped out, leaving only high-density array copper electrodes on the water-based adhesive tape.

[0049] Step S3, using an adhesive to respectively fix the array metal electrodes on the top surface and the bottom surface of the porous conductive gel, so that the array metal electrodes are crossed in the top surface and the bottom surface directions, forming a 90-degree angle

[0050] In a specific embodiment, the adhesive is a composite adhesive containing Ecoflex and carbon nanotubes. Ecoflex is a plastic material with good flexibility, cold resistance, heat resistance, and chemical resistance. The composite adhesive of Ecoflex and carbon nanotubes is prepared in the following way: configuring a mixed solution of Ecoflex and carbon nanotubes, oscillating mixing, re-mixing, and removing bubbles to obtain a uniformly mixed Ecoflex / carbon nanotube composite adhesive. In some embodiments, the mass ratio of Ecoflex to carbon nanotubes in the Ecoflex / carbon nanotube composite adhesive is 1:15-1:20. For example, 0.24 g of carbon nanotubes is poured into 2 g of Ecoflex A agent and 2 g of Ecoflex B agent. Due to the high concentration of carbon nanotubes, the Ecoflex / carbon nanotube composite adhesive has excellent electrical conductivity, and its resistance is much smaller than that of the porous conductive gel itself. Therefore, when preparing a pressure sensor array, the self-resistance of the adhesive will not affect the resistance change of the sensor itself.

[0051] The Ecoflex / carbon nanotube composite adhesive is evenly applied on the array copper electrode, and then the top surface of the porous conductive colloid is covered on the copper electrode, and the copper electrode is tightly combined with the porous conductive colloid by careful pressing. In some embodiments, the porous conductive colloid is cut into square blocks with the same size as the array copper electrode by using laser cutting; during operation, the cutting speed of the ultraviolet laser cutting machine is 300, the cutting power is 100%, and the cutting times are 40 times.

[0052] The porous conductive colloid with the array copper electrode attached to the top surface is transferred to the baking table, the temperature is set to 120-150°C, and the copper electrode is fixed on the top surface of the porous conductive colloid. Remove the heat release tape that has failed due to heating, and separate the array copper electrode from the glass sheet.

[0053] With respect to the array copper electrode that has been attached, the direction of another array copper electrode is rotated by 90 degrees, and then the above-mentioned operation is repeated to attach and fix the array metal electrode on the bottom surface of the porous conductive colloid, thereby obtaining a porous conductive colloid with the top surface and bottom surface copper electrodes intersecting at a 90-degree angle. The intersecting electrodes are distributed in a grid pattern, which can achieve large-area sensing efficiency; the overlapping area of the upper and lower electrode layers is regarded as a sensing unit, and these units are distributed in an array form to achieve large-area sensing efficiency.

[0054] In this step, the copper electrode array is transferred from the surface of the glass sheet to the surface of the porous conductive colloid by utilizing the difference in binding energy between different material interfaces through specific process steps.

[0055] Step S4, dissolving the hydrosol tape by water flow, and obtaining a high-density ultra-thin flexible pressure sensor array after drying

[0056] In a specific embodiment, the porous conductive colloid with copper electrodes attached to both surfaces is washed under a small water flow to dissolve the hydrosol tape on the surface of the copper electrode, and then placed in a 60°C oven to dry the moisture, thereby obtaining a high-density ultra-thin pressure sensor array.

[0057] By using the technical scheme of the present embodiment, a high-density ultra-thin pressure sensor array is prepared, as shown in Figure 1 The sensor array is a square with a side length of 5 cm, a thickness of 0.8 mm, and an ultra-thin flexible pressure sensor. Each electrode is a square of 3 mm, and the spacing between the electrodes is 1 mm.

[0058] Slowly press under the universal pressure testing machine until the pressure reaches 12N and returns. The contact area is 1 square millimeter when pressing, and the pressure and resistance are measured by a source table power supply. The relationship between the pressure and the resistance is shown in Figure 1 The ultra-thin pressure sensor array has high sensitivity response at low pressure and a wide sensitivity range of 120Kpa.

[0059] To ensure that the sensor can measure pressure completely under different pressures, the universal pressure testing machine applies a pressure of 3N, 4.5N, 6N, 7.5N, and 9N to the pressure sensor, and the pressure is 30kPa, 45kPa, 60kPa, 75kPa, and 90kPa, respectively. After reaching the high point, it returns and repeats several times to obtain the repeatability curve as shown in Figure 2 From the figure, it can be seen that the sensor shows good repeatability under 5 different pressures. Compared with the prior art, in 2021, Wang et al. developed a pressure sensor composed of MXene, multi-walled carbon nanotubes (MWCNT) and thermoplastic polyurethane (TPU). In the multiple cycle test, the resistance change rate tested by the sensor showed obvious difference; thus it can be illustrated that the flexible pressure sensor provided in the embodiment has good repeatability for pressure sensing.

[0060] Figure 4 The minimum response pressure of the ultrathin pressure sensor array of embodiment 1 can be seen from the figure. The ultrathin pressure sensor array still shows complete response when receiving a pressure of 790Pa.

[0061] Figure 5 For the sensor response time test data, it can be seen from Figure 5 that the resistance of the ultrathin pressure sensor array changes correspondingly within 0.15 seconds after receiving the load. Compared with the prior art, in 2021, Wang et al. developed a pressure sensor composed of MXene, multi-walled carbon nanotubes (MWCNT) and thermoplastic polyurethane (TPU). The response time thereof is about 0.4 seconds; thus it can be illustrated that the flexible pressure sensor provided in the embodiment has faster response speed.

[0062] The ultrathin pressure sensor array prepared by the embodiment can have an area of more than square meters by adjusting the length and width of the mold frame, and has light weight. From the detection data of Figures 2-5 , it can be known that it has the advantages of high-precision measurement, wide measurement range, high stability, and fast response; at the same time, the electrodes are arranged in the form of a high-density array, which can measure the pressure distribution of multiple points at the same time, realizing low-cost pressure measurement. At the same time, the whole preparation process has simple process flow, low manufacturing cost, and is suitable for large-scale and batch manufacturing.

[0063] Embodiment 2

[0064] The embodiment provides a preparation method of a high-density ultrathin flexible pressure sensor array, which comprises the following steps:

[0065] Step 1, prepare a porous conductive colloid with a porous structure and uniform distribution of conductive particles, and the components of the porous conductive colloid are carbon nanotubes and polydimethylsiloxane

[0066] Step one of the embodiment, the specific implementation is basically the same as step S1 of embodiment 1.

[0067] Step two, use adhesive to fix the metal foil on the top and bottom surfaces of the porous conductive gel respectively by adhesion

[0068] In a specific embodiment, the adhesive is still selected from Ecoflex / carbon nanotube composite adhesive.

[0069] For example: evenly spread Ecoflex / carbon nanotube composite adhesive on a 5cm square copper foil, then cover the top surface of the porous conductive gel on the copper foil, align the edges, and press carefully to make the copper foil and the porous conductive gel tightly combined.

[0070] Step three, use ultraviolet laser to cut the metal foil, so that the top surface metal electrode and the bottom surface metal electrode of the cut porous conductive gel are crossed and form a 90 degree angle

[0071] In a specific embodiment, import the high-density array design diagram through laser marking software, set the cutting speed of the ultraviolet laser cutting machine to 300, the cutting power to 30%, and the cutting times to 26; turn on the red light contour, align the copper foil for cutting, and use the above parameters to control the cutting effect to cut only through the copper foil, without cutting the porous conductive gel below the copper foil.

[0072] Step four, remove the excess metal foil between the array electrodes, and obtain a high-density ultra-thin flexible pressure sensor array

[0073] Use tools such as tweezers to slowly remove the excess copper foil between the array electrodes, so that only high-density array copper electrodes are left on the conductive film, forming a pressure sensor array.

[0074] The process method of the embodiment, compared with embodiment 1, the main difference is to adjust the order of transferring the metal foil and cutting the metal foil, directly cutting on the transferred copper foil, which can make the electrode unit of the sensor cross more accurately, and the crosstalk is smaller when testing the pressure imaging.

[0075] In some embodiments, a high-density ultra-thin flexible pressure sensor array is also provided, which is prepared by the high-density ultra-thin flexible pressure sensor array preparation method described in the embodiment.

[0076] It should be pointed out finally that the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit the same; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can still be modified, or some or all of the technical features can be replaced equivalently; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should be covered in the scope of the claims and the specification of the present application.

Claims

1. A method for fabricating a high-density ultra-thin flexible pressure sensor array, comprising: The method comprises the following steps: ​ Preparation of a porous conductive gel with a porous structure and uniformly distributed conductive particles, preparation of a mixed solution of carbon nanotubes and polydimethylsiloxane; A curing agent and salt particles obtained by evaporation crystallization and grinding are sequentially added to the mixed solution, and stirring is performed to obtain a first mixture; the first mixture is poured into a mold, the surface is flattened, and then heating and curing are performed; after the first mixture is cooled and immersed in water, the salt particles in the mixture are dissolved and removed to obtain a second mixture; the second mixture is dried to obtain a porous conductive gel with a porous structure and uniformly distributed conductive particles; the components of the porous conductive gel are carbon nanotubes and polydimethylsiloxane; A metal foil is fixed on a glass sheet using double-sided thermal release tape and water-based adhesive tape, and the metal foil is cut by laser to prepare an array metal electrode; The array metal electrode is fixed on the top surface and the bottom surface of the porous conductive gel by adhesion using an adhesive, so that the array metal electrode is crossed in the direction of the top surface and the bottom surface, and the angle between the top surface and the bottom surface is 90 degrees; The water-based adhesive tape is dissolved by water flow, and then dried to obtain a high-density ultra-thin flexible pressure sensor array.

2. The method of claim 1, wherein the method further comprises: The mass ratio of carbon nanotubes to polydimethylsiloxane is 1:30-1:40, and the particle size of the salt is 100 mesh.

3. The method of claim 1, wherein the method further comprises: The first mixture is heated and cured using a mold, and the thickness of the first mixture after curing is controlled by setting the depth of the mold recess.

4. The method of claim 1, wherein the method further comprises: The metal foil is a copper foil, and the thickness of the copper foil is 5 μm.

5. The method of claim 1, wherein the method further comprises: The adhesive is a composite adhesive containing Ecoflex and carbon nanotubes.

6. A high-density ultra-thin flexible pressure sensor array, characterized in that, The high-density ultra-thin flexible pressure sensor array is prepared by the method of any one of claims 1-5.

7. A method of fabricating a high-density ultra-thin flexible pressure sensor array, comprising: The method comprises the following steps: Preparation of a porous conductive gel with a porous structure and uniformly distributed conductive particles, preparation of a mixed solution of carbon nanotubes and polydimethylsiloxane; A curing agent and salt particles obtained by evaporation crystallization and grinding are sequentially added to the mixed solution, and stirring is performed to obtain a first mixture; the first mixture is poured into a mold, the surface is flattened, and then heating and curing are performed; after the first mixture is cooled and immersed in water, the salt particles in the mixture are dissolved and removed to obtain a second mixture; the second mixture is dried to obtain a porous conductive gel with a porous structure and uniformly distributed conductive particles; the components of the porous conductive gel are carbon nanotubes and polydimethylsiloxane; A curing agent and salt particles obtained by evaporation crystallization and grinding are sequentially added to the mixed solution, and stirring is performed to obtain a first mixture; the first mixture is poured into a mold, the surface is flattened, and then heating and curing are performed; after the first mixture is cooled and immersed in water, the salt particles in the mixture are dissolved and removed to obtain a second mixture; the second mixture is dried to obtain a porous conductive gel with a porous structure and uniformly distributed conductive particles; the components of the porous conductive gel are carbon nanotubes and polydimethylsiloxane; The array electrode is removed between the array electrodes and the excess metal foil cut off to obtain a high-density ultra-thin flexible pressure sensor array.

8. The method of claim 7, wherein the method further comprises: The laser is an ultraviolet laser, the cutting power is 30%, and the cutting frequency is 26 times.

9. A high-density ultra-thin flexible pressure sensor array, characterized in that, The high-density ultra-thin flexible pressure sensor array is prepared by the method of any one of claims 7 or 8. The high-density ultra-thin flexible pressure sensor array is prepared by the method of any one of claims 7 or 8.

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