Preparation method of high-density ultrathin flexible pressure sensor array and sensor

Abstract

The invention provides a preparation method of a high-density ultrathin flexible pressure sensor array, and the method comprises the steps: preparing a porous conductive colloid with a porous structure and uniformly distributed conductive particles, and the porous conductive colloid comprises the components of a carbon nanotube and polydimethylsiloxane; the method comprises the following steps: flatly fixing a metal foil on a glass sheet by using a double-sided heat release adhesive tape and a hydrosol tape, and carrying out laser cutting on the metal foil to prepare an array metal electrode; respectively fixing the array metal electrodes on the top surface and the bottom surface of the porous conductive colloid by using an adhesive in a bonding manner, so that the array metal electrodes are crossed in the directions of the top surface and the bottom surface to form an included angle of 90 degrees; and dissolving the hydrosol belt through water flow, and drying to obtain the high-density ultrathin flexible pressure sensor array. The technical problem that a large-area flexible pressure sensor for a wearable medical electronic product cannot give consideration to both high sensitivity and wide pressure detection range can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of flexible electronic components, and in particular to a method for preparing a high-density ultra-thin flexible pressure sensor array and a sensor. Background Art

[0002] Wearable medical electronics, as the data source of the Internet of Things, can capture the physiological or behavioral characteristics of the human body in real time. It is expected to transform the traditional disease-centered medical service system into a personalized medical model centered on disease prevention, and is the key to realizing smart medical care. Among them, piezoresistive flexible pressure sensors, due to their low energy consumption, high sensitivity, simple process, 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 have attracted much attention in the next generation of wearable medical electronics.

[0003] At present, for some integrated nursing monitoring clothing, large-area flexible pressure sensors are needed. However, once the area of ​​the flexible sensors in the prior art is increased, the structure and material properties of the flexible pressure sensors will be affected, and complex electrode layout and connection methods are required, which will result in a situation where high sensitivity and a wide pressure detection range cannot be taken into account at the same time; and the larger the area of ​​the flexible sensor is, the heavier the weight of the clothes will be after it is filled into the clothes, making it inconvenient to wear. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention proposes a method for preparing a high-density ultra-thin flexible pressure sensor array and a sensor to solve the technical problem that large-area flexible pressure sensors used in wearable medical electronic products in the prior art cannot take into account both high sensitivity and a wide pressure detection range.

[0005] The technical solution adopted by the present invention is as follows:

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

[0007] A porous conductive colloid with a porous structure and uniformly distributed conductive particles is prepared, wherein the components of the porous conductive colloid are carbon nanotubes and polydimethylsiloxane; a metal foil is flatly fixed on a glass sheet using a double-sided thermal release tape and a water-soluble tape, and the metal foil is laser cut to prepare an array metal electrode; an adhesive is used to bond and fix the array metal electrodes on the top and bottom surfaces of the porous conductive colloid, respectively, so that the array metal electrodes are crossed and form an angle of 90 degrees in the directions of the top and bottom surfaces; the water-soluble tape is dissolved by water flow, and then dried to obtain a high-density ultra-thin flexible pressure sensor array.

[0008] Furthermore, a porous conductive colloid having a porous structure and uniformly distributed conductive particles is prepared, comprising:

[0009] A mixed liquid of carbon nanotubes and polydimethylsiloxane is prepared; a curing agent and salt particles ground by evaporation, crystallization and grinding are sequentially added to the mixed liquid, and the mixture is stirred to obtain a first mixture; the first mixture is heated and cured, and the cured first mixture is cooled and then immersed in water to dissolve and remove the salt particles in the mixture to obtain a second mixture; the second mixture is dried to obtain a porous conductive colloid having a porous structure and uniformly distributed conductive particles.

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

[0011] Furthermore, 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 depression.

[0012] Furthermore, the metal foil is copper foil, and the thickness of the copper foil is 5 μm.

[0013] Furthermore, the adhesive adopts 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 high-density ultra-thin flexible pressure sensor array preparation method described in the first aspect.

[0015] On the third aspect, another method for preparing a high-density ultra-thin flexible pressure sensor array is provided, including: preparing a porous conductive colloid with a porous structure and uniformly distributed conductive particles, the components of the porous conductive colloid are carbon nanotubes and polydimethylsiloxane; using an adhesive to fix metal foil on the top and bottom surfaces of the porous conductive colloid by bonding respectively; using a laser to cut the metal foil so that the directions of the metal electrode on the top surface and the metal electrode on the bottom surface of the porous conductive colloid after cutting are crossed and form an angle of 90 degrees; removing the excess metal foil between the array electrodes that has been cut off to obtain a high-density ultra-thin flexible pressure sensor array.

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

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

[0018] It can be seen from the above technical solution that the beneficial technical effects of the present invention are as follows:

[0019] 1. The area can be increased to more than square meters by adjusting the length and width of the mold frame, and it is lightweight. 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 a high-density array, which can measure the pressure distribution of multiple points at the same time, realizing low-cost pressure measurement.

[0020] 2. The entire preparation process is simple and easy to switch between steps. The order of transferring the metal foil and laser cutting the metal foil can be adjusted. Cutting can be performed directly on the transferred copper foil, which can make the electrode units of the sensor cross more accurately and reduce crosstalk during pressure imaging testing. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the specific embodiments or the prior art description. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn according to the actual scale.

[0022] Figure 1 This is a physical picture of the ultra-thin pressure sensor array of Example 1 of the present invention;

[0023] Figure 2 is a sensitivity curve diagram of the ultra-thin pressure sensor array according to Example 1 of the present invention;

[0024] Figure 3 This is a periodic curve diagram of the ultra-thin pressure sensor array of Example 1 of the present invention under pressures of 30 kPa, 45 kPa, 60 kPa, 75 kPa, and 90 kPa;

[0025] Figure 4 This is a diagram of the minimum response pressure of the ultra-thin pressure sensor array according to Example 1 of the present invention;

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

[0027] The following embodiments of the technical solution of the present invention are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and are therefore only used as examples, and cannot be used to limit the protection scope of the present invention.

[0028] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in this application should have the common meanings understood by those skilled in the art to which the present invention belongs.

[0029] Example 1

[0030] The inventors found through research that if the area of ​​the flexible sensor is to be enlarged in the application scenario, more signal transmission paths and contact resistances may be introduced in the process of increasing the area. These factors will 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 complicated, thereby affecting the sensitivity. In terms of material properties, when a wide pressure detection range is to be achieved, the material needs to have a suitable elastic modulus and compressibility. However, in the case of increasing the area, it becomes difficult to keep these properties uniform across the entire large area of ​​the material. For example, for a piezoresistive flexible sensor, it is difficult to ensure that a consistent resistance change can be produced at different positions when a large area of ​​conductive material and substrate material is subjected to pressure to balance high sensitivity and a 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 of the material, the consistency of thickness, etc., and these process defects will also cause the sensor to be unable to balance high sensitivity and a wide pressure detection range.

[0031] In combination with the above research results, this embodiment provides a method for preparing 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 uniformly distributed conductive particles, wherein the components of the porous conductive colloid are carbon nanotubes and polydimethylsiloxane

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

[0034] Step S11: preparing a mixture 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, 0.15 g of carbon nanotubes is poured into 5 g of PDMS (polydimethylsiloxane) main agent, stirred for 5 minutes, and ultrasonically vibrated for 1 hour to obtain a mixed solution of carbon nanotubes and polydimethylsiloxane.

[0036] Step S12: Add the curing agent and the salt particles ground by evaporation, crystallization and grinding to the mixed solution in sequence, and stir to obtain a first mixture.

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

[0038] The salt particles after evaporation, crystallization and grinding are prepared in the following manner: 200 ml of water is added to an evaporating dish, and salt is slowly added to prepare a saturated solution; then, evaporation and crystallization are performed on a heating table at 350° C. to obtain crystallized salt; and then, the crystallized salt is poured into a mortar in small amounts and ground several times to prepare fine-grained salt. Preferably, the particle size of the salt is 100 mesh.

[0039] Step S13, heating and curing the first mixture, cooling the cured first mixture, and soaking it in water to dissolve and remove salt particles in the mixture to obtain a second mixture

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

[0041] Pour the first mixture into the mold and flatten the surface, then place the mold on a heating table set at 130-150°C for 10 minutes for heat treatment. Wait for the first mixture to solidify, take it out of the mold, and let it cool naturally at room temperature. After the solidified first mixture cools down, soak it 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 mixture of carbon nanotubes and polydimethylsiloxane containing salt particles does not adhere well enough to the metal electrode.

[0042] Step S14: drying the second mixture to obtain a porous conductive colloid having a porous structure and uniformly distributed conductive particles.

[0043] In a specific embodiment, the second mixture is placed in an oven at 60° C. to dry the moisture, thereby obtaining a porous conductive colloid having a porous structure and conductive particles evenly distributed therein, wherein the porous conductive colloid is a whole square.

[0044] In this step, a porous conductive colloid is made by a customized mold. The thickness of the porous conductive colloid is controlled by changing the depth of the mold while ensuring good performance of the porous conductive colloid. The weight of the entire flexible sensor is controlled while ensuring the sensitivity of the sensor. This process has the advantages of strong controllability of the preparation process, high material utilization, short preparation cycle, high efficiency, and wide application range. Multiple repeated experiments can be carried out in a short time.

[0045] Step S2: Use double-sided thermal release tape and water-soluble tape to flatly fix the metal foil on the glass sheet, and perform laser cutting on the metal foil to prepare the array metal electrode.

[0046] In a specific embodiment, the metal foil is copper (Cu) foil, and the thickness is preferably 5 μm. The copper foil is cut into a suitable size according to the processing requirements, and then a layer of double-sided thermal release tape, a layer of water-soluble tape, and a layer of copper foil are sequentially adhered to the surface of the glass sheet from bottom to top, so that the copper foil / water-soluble tape composite material is evenly fixed on the glass sheet through the double-sided thermal release tape. The gaps between the copper foil, the water-soluble tape, and the glass sheet are removed by pressing to prevent the subsequent laser cutting quality from being affected by the presence of surface protrusions.

[0047] Ultraviolet laser can irradiate the surface of the material through high-density and high-energy laser beams, destroy the molecular bonds of the material, and form cutting. At the same time, ultraviolet laser is a cold processing form. The laser emitter emits high-energy ultraviolet photons to hit the surface of the material, directly destroying the molecular bonds on the surface of the material without generating high heat. It is suitable for preparing high-density electrode arrays.

[0048] In a specific implementation, a high-density array design drawing is imported through laser marking software, and the cutting speed of the ultraviolet laser cutting machine is set to 300, the cutting power is set to 35%, and the number of cuts is set to 22. Turn on the red light profile, aim at the copper foil for cutting, and the cutting effect is that the laser only cuts the surface copper foil of the transparent copper foil / water-soluble adhesive tape composite material, and does not cut the underlying water-soluble adhesive tape. Then use tools, such as tweezers, to slowly clip out the excess copper foil that has been cut between the array electrodes, so that only the high-density array copper electrodes remain on the water-soluble adhesive tape.

[0049] Step S3: Use adhesive to fix the array metal electrodes on the top and bottom surfaces of the porous conductive colloid by bonding, so that the array metal electrodes cross each other at a 90-degree angle in the direction of the top and bottom surfaces.

[0050] In a specific embodiment, the adhesive is a composite viscose comprising Ecoflex and carbon nanotubes, and Ecoflex is a plastic material with good flexibility, cold resistance, heat resistance and chemical resistance. The composite viscose of Ecoflex and carbon nanotubes is prepared in the following manner: a mixed solution of Ecoflex and carbon nanotubes is prepared, oscillated and mixed, mixed again, and bubbles are removed to obtain a uniformly mixed Ecoflex / carbon nanotube composite viscose. In some embodiments, in the Ecoflex / carbon nanotube composite viscose, the mass ratio of Ecoflex and carbon nanotubes is 1:15-1:20. For example, 0.24g of carbon nanotubes is poured into 2g of EcoflexA agent and 2g of EcoflexB agent. Due to the high concentration of carbon nanotubes, the Ecoflex / carbon nanotube composite viscose has excellent conductivity, and its resistance is much smaller than the resistance of the porous conductive colloid itself. Therefore, when preparing the pressure sensor array, the inherent 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 carefully pressed to make the copper electrode and the porous conductive colloid tightly bonded. In some embodiments, the porous conductive colloid is cut into square blocks of the same size as the array copper electrode using laser cutting; during operation, the ultraviolet laser cutting machine has a cutting speed of 300, a cutting power of 100%, and a cutting number of 40 times.

[0052] The porous conductive colloid with the array copper electrode bonded on the top surface is transferred to a drying table, and the temperature is set to 120-150°C for 10 minutes, and the copper electrode is fixed on the top surface of the porous conductive colloid. The heat release tape that fails due to heating is removed to separate the array copper electrode from the glass sheet.

[0053] Relative to the already bonded array copper electrode, rotate the direction of another array copper electrode by 90 degrees, and then repeat the above-mentioned operation to bond and fix the array metal electrode on the bottom surface of the porous conductive colloid, and obtain a porous conductive colloid with the top and bottom copper electrodes intersecting at a 90-degree angle. The cross electrodes are distributed in a grid pattern, which can achieve large-area sensing effect; the overlapping area of ​​the upper and lower electrode layers is used as a sensing unit, and these units are distributed in an array form to achieve large-area sensing effect.

[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 through specific process steps by utilizing the difference in binding energy between interfaces of different materials.

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

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

[0057] By adopting the technical solution of this embodiment, a high-density ultra-thin pressure sensor array is prepared. Figure 1 As shown, the sensor array is a square with a side length of 5 cm and a thickness of 0.8 mm, which is an ultra-thin flexible pressure sensor. Each electrode is a 3 mm square, and the interval between electrodes is 1 mm.

[0058] Slowly pressurize the universal pressure testing machine until the pressure reaches 12N and then return. When pressurizing, the contact area is 1 square millimeter. The source meter is used to measure the pressure and the relationship between the pressure and resistance is measured as follows: Figure 1 As shown in the figure, the ultra-thin pressure sensor array has a 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, a universal pressure testing machine applies 3N, 4.5N, 6N, 7.5N, and 9N pressures to the pressure sensor. The pressures are 30kPa, 45kPa, 60kPa, 75kPa, and 90kPa respectively. After reaching the highest point, it returns and repeats several times to obtain the following results: Figure 2 As shown in the repeatability curve, 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 multiple cycle tests, the resistance change rate tested by the sensor showed obvious differences; this shows that the flexible pressure sensor provided in this embodiment has good repeatability for pressure sensing.

[0060] Figure 4 This is the minimum response pressure of the ultra-thin pressure sensor array of Example 1. It can be seen from the figure that the ultra-thin pressure sensor array still exhibits a complete response when subjected to a pressure of 790Pa.

[0061] Figure 5 The sensor response time test data is from Figure 5 It can be seen that after the ultra-thin pressure sensor array receives the load, the resistance changes accordingly within 0.15 seconds. 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) with a response time of about 0.4 seconds; this shows that the flexible pressure sensor provided in this embodiment has a faster response speed.

[0062] The ultra-thin pressure sensor array prepared by this embodiment can be made larger than square meters in area by adjusting the length and width of the mold frame, and is lightweight. Figure 2-5 The test data shows 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 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 entire preparation process is simple, the manufacturing cost is low, and it is suitable for large-scale and batch manufacturing.

[0063] Example 2

[0064] This embodiment provides a method for preparing a high-density ultra-thin flexible pressure sensor array, comprising the following steps:

[0065] Step 1: Prepare 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.

[0066] The specific implementation of step 1 of this embodiment is basically the same as step S1 of embodiment 1.

[0067] Step 2: Use adhesive to fix the metal foil on the top and bottom surfaces of the porous conductive colloid by bonding

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

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

[0070] Step 3: Use ultraviolet laser to cut the metal foil so that the metal electrode on the top and the metal electrode on the bottom of the porous conductive colloid are crossed and form a 90-degree angle.

[0071] In a specific implementation, a high-density array design drawing is imported through laser marking software, and the cutting speed of the ultraviolet laser cutting machine is set to 300, the cutting power is 30%, and the number of cutting times is 26 times; the red light profile is turned on, and the copper foil is aligned for cutting. The above parameters can be used to control the cutting effect so that the laser only cuts through the copper foil, and does not cut the porous conductive colloid under the copper foil.

[0072] Step 4: Remove the excess metal foil between the array electrodes to obtain a high-density ultra-thin flexible pressure sensor array.

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

[0074] The process method of this embodiment, compared with embodiment 1, mainly differs in that the order of transferring the metal foil and laser cutting the metal foil is adjusted, and cutting is performed directly on the transferred copper foil, which can make the electrode units of the sensor cross more accurately and reduce crosstalk during pressure imaging testing.

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

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. 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 invention, and they should all be included in the scope of the claims and specification of the present invention.

Claims

1. A method for preparing a high-density ultra-thin flexible pressure sensor array, characterized in that: include: A porous conductive colloid with a porous structure and uniformly distributed conductive particles is prepared, wherein the components of the porous conductive colloid are carbon nanotubes and polydimethylsiloxane; The metal foil is fixed flatly on the glass sheet using double-sided thermal release tape and water-soluble tape, and the metal foil is laser cut to prepare array metal electrodes; Using an adhesive to fix the array metal electrodes on the top and bottom surfaces of the porous conductive colloid by bonding, respectively, so that the array metal electrodes are crossed in the direction of the top and bottom surfaces and form a 90-degree angle; The hydrosol tape is dissolved by water flow and then dried to obtain a high-density ultra-thin flexible pressure sensor array.

2. The method for preparing a high-density ultra-thin flexible pressure sensor array according to claim 1, characterized in that: A porous conductive colloid having a porous structure and uniformly distributed conductive particles is prepared, comprising: preparing a mixed solution of carbon nanotubes and polydimethylsiloxane; Adding a curing agent and salt particles ground by evaporation, crystallization and grinding to the mixed solution in sequence, stirring the mixture to obtain a first mixture; The first mixture is heated and solidified, and after the solidified first mixture is cooled, it is immersed in water to dissolve and remove salt particles in the mixture to obtain a second mixture; The second mixture is dried to obtain a porous conductive colloid having a porous structure and conductive particles evenly distributed.

3. The method for preparing a high-density ultra-thin flexible pressure sensor array according to claim 2, characterized in that: The mass ratio of carbon nanotubes to polydimethylsiloxane is 1:30-1:40, and the particle size of the salt is 100 mesh.

4. The method for preparing a high-density ultra-thin flexible pressure sensor array according to claim 2, characterized in that: 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 depression.

5. The method for preparing a high-density ultra-thin flexible pressure sensor array according to claim 1, characterized in that: The metal foil is copper foil, and the thickness of the copper foil is 5 μm.

6. The method for preparing a high-density ultra-thin flexible pressure sensor array according to claim 1, characterized in that: The adhesive is a composite adhesive containing Ecoflex and carbon nanotubes.

7. 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 preparation method of any one of claims 1 to 6.

8. A method for preparing a high-density ultra-thin flexible pressure sensor array, characterized in that: include: A porous conductive colloid with a porous structure and uniformly distributed conductive particles is prepared, wherein the components of the porous conductive colloid are carbon nanotubes and polydimethylsiloxane; Using an adhesive to fix the metal foil on the top and bottom surfaces of the porous conductive colloid by bonding; The metal foil is cut by using a laser so that the metal electrode on the top surface and the metal electrode on the bottom surface of the porous conductive colloid are crossed and form a 90-degree angle. The excess metal foil that is cut off between the array electrodes is removed to obtain a high-density ultra-thin flexible pressure sensor array.

9. The method for preparing a high-density ultra-thin flexible pressure sensor array according to claim 1, characterized in that: The laser is an ultraviolet laser, and the cutting speed of the ultraviolet laser cutting machine is set to 300, the cutting power is 30%, and the number of cutting times is 26.

10. 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 preparation method of claim 8 or 9.

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