Pressure sensor and preparation method thereof

Abstract

The invention discloses a pressure sensor and a preparation method thereof. The preparation method comprises the following steps: providing a flexible substrate layer, a frame layer and a packaging layer; an array electrode screen plate and an electrode substrate film are fixed to the corresponding positions of a screen printing machine respectively, the electrode substrate film is located below the array electrode screen plate, then the array electrode screen plate is coated with an electrode material, the electrode material is scraped to the surface of the electrode substrate film through the array electrode screen plate through a scraper, and the electrode material is dried to obtain the electrode. Printing an electrode material on the electrode substrate film to obtain an electrode layer, and bonding the electrode layer on the surface of the flexible substrate layer by using an adhesive; bonding the frame layer on the surface of the electrode layer by using an adhesive; mixing ionic gel with an initiator to obtain an ionic gel solution, dispensing the ionic gel solution in the frame layer, and then carrying out ultraviolet curing treatment to obtain an ionic gel layer; and bonding the packaging layer on the surface of the ionized water gel layer by using an adhesive.

Description

Technical Field

[0001] The present invention relates to the field of flexible electronic technology, and in particular to a pressure sensor and a preparation method thereof. Background Art

[0002] In recent years, ionic hydrogels have attracted extensive attention in the development of flexible tactile sensors due to their unique properties, such as ionic conductivity, flexibility, and tissue similarity. Due to their Young's modulus close to that of human tissue, they can bend and deform their surfaces with applied pressure, enabling them to detect tactile pressure in a more natural and intuitive way. Through the free movement of ions in response to pressure gradients, ionic hydrogels can directly generate ionic currents and achieve self-powered capabilities. This feature gives ionic hydrogels great potential for application in artificial skin sensors, wearable devices, and user-interaction sensing devices.

[0003] In the prior art, ionic hydrogel sensors with self-powered capabilities are mostly whole-piece strain sensing and low-resolution regional pressure sensing due to the material curing sensitivity and immature hydrogel array preparation process. They cannot meet the needs of high-precision pressure point sensing in a small range and are limited in many application scenarios. In addition, the current flexible hydrogel sensors have problems such as modulus mismatch and poor interface stability in the electrode interface bonding process, which will reduce the quality of the sensing signal.

[0004] Therefore, the prior art still needs to be improved and developed. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, the present invention provides a pressure sensor and a method for preparing the same, so as to solve the problem of low resolution of the existing pressure sensor.

[0006] The technical solution adopted by the present invention to solve the above technical problems is as follows:

[0007] A first aspect of the present invention provides a method for preparing a pressure sensor, the method comprising the following steps:

[0008] Providing a flexible substrate layer, a frame layer and a packaging layer;

[0009] The array electrode screen and the electrode base film are fixed to the corresponding positions of the screen printer respectively, the electrode base film is located below the array electrode screen, and then the electrode material is coated on the array electrode screen, and the electrode material is scraped through the array electrode screen to the surface of the electrode base film by a scraper, and the electrode material is printed on the electrode base film to obtain an electrode layer, and the electrode layer is bonded to the surface of the flexible base layer by an adhesive;

[0010] Using an adhesive to bond the frame layer to the surface of the electrode layer;

[0011] The ion gel is mixed with an initiator to obtain an ion gel solution, the ion gel solution is dispensed into the frame layer, and then subjected to ultraviolet curing treatment to obtain an ion hydrogel layer;

[0012] The encapsulation layer is bonded to the surface of the ionic hydrogel layer using an adhesive.

[0013] Preferably, the electrode substrate film is one of a thermoplastic polyurethane rubber film, a thermoplastic polyester material film, and a polyimide film, and the electrode material is one of a silver paste, a carbon paste, and a conductive polymer.

[0014] Preferably, the step of mixing the ion gel with the initiator to obtain the ion gel solution is specifically: dissolving the ion gel pair, the crosslinking agent and the initiator in water, and stirring to obtain the ion gel solution.

[0015] Preferably, the ion gel pair is a pair of acrylamide and acrylic acid, acrylonitrile and N-isopropylacrylamide, the initiator is one of 2959 photoinitiator, APS thermal curing agent, LAP photocuring agent, potassium persulfate, and the crosslinking agent is one of isophthalimide, N,N'-methylenebisacrylamide, and polyethylene glycol diacrylate.

[0016] Preferably, in the ion gel solution, the concentration of the ion gel pair is 5wt%-15wt%, and the concentration of the cross-linking agent is 1wt%-3wt%.

[0017] Preferably, the mass ratio of the acrylic acid to acrylamide is 1:1 to 3:1, and the mass ratio of acrylonitrile to N-isopropylacrylamide is 1:1 to 3:1.

[0018] Preferably, the UV curing treatment is specifically: irradiating with a UV lamp with a wavelength of 365nm-380nm and a power of 20W-25W for 10min-15min.

[0019] Preferably, after bonding the frame layer to the surface of the electrode layer using an adhesive, the method further comprises the steps of: immersing the bonded flexible substrate layer, electrode layer and frame layer in a benzophenone-ethanol solution for 15 min-20 min, and then performing plasma treatment for 20 s-1 min.

[0020] Preferably, the thickness of the frame layer is 0.05-2 cm.

[0021] According to a second aspect of the present application, a pressure sensor is provided. The pressure sensor is prepared by the above-mentioned preparation method.

[0022] Beneficial effects:

[0023] The present invention discloses a pressure sensor and a preparation method thereof. The pressure sensor prepared by the present invention is composed of a flexible substrate layer, an electrode layer, a frame layer, an ion gel layer and an encapsulation layer. The frame layer is used to increase the isolation between the sensing units, avoid signal crosstalk, and improve the sensing quality. The ion gel sensing layer is prepared by dispensing glue in the frame layer and performing UV curing to achieve a small-area high-density sensing array, thereby solving the problem of low sensing resolution of common hydrogel devices. By using electrode materials to prepare the electrode layer on the electrode substrate film through a screen printing process, a stable interface bonding can be achieved, thereby solving the problem of poor signal quality caused by the interface. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The overall structure diagram of the pressure sensor provided in Example 1 of the present invention;

[0025] Figure 2 A schematic diagram of the electrode pattern of the pressure sensor prepared in Example 1 of the present invention;

[0026] Figure 3 This is a schematic diagram of the frame layer of the pressure sensor prepared in Example 1 of the present invention;

[0027] Figure 4 A schematic diagram of the combination of a flexible substrate layer, an electrode layer and a frame layer of a pressure sensor prepared in Example 1 of the present invention;

[0028] Figure 5 This is an overall physical picture of the pressure sensor prepared in Example 1 of the present invention;

[0029] Figure 6 A layered decomposition structure diagram of the pressure sensor provided in Example 1 of the present invention; wherein 1 is a packaging layer, 2 is an ion gel layer, 3 is a frame layer, 4 is a connection portion between the FPC and the electrode layer, 5 is a connection portion between the FPC and the adapter board, 6 is an electrode layer, 7 is a negative electrode on the electrode layer, 8 is a positive electrode on the electrode layer, and 9 is a flexible substrate layer;

[0030] Figure 7 A flowchart of a pressure positioning visualization program of a pressure sensor provided by a preferred embodiment of the present invention;

[0031] Figure 8 An application effect diagram of a pressure sensor provided by a preferred embodiment of the present invention;

[0032] Fig. 9 The voltage output curve of the pressure sensor prepared in Examples 1-4 of the present invention;

[0033] Fig.10 Response recovery curves of the pressure sensors prepared in Examples 1 and 5-7 of the present invention. DETAILED DESCRIPTION

[0034] The present invention provides a pressure sensor and a method for preparing the same. To make the purpose, technical solution and effect of the present invention clearer and more specific, the present invention is further described in detail below. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0035] An embodiment of the present invention provides a method for preparing a pressure sensor, the method comprising the following steps:

[0036] Providing a flexible substrate layer, a frame layer and a packaging layer;

[0037] The array electrode screen and the electrode base film are fixed to the corresponding positions of the screen printer respectively, the electrode base film is located below the array electrode screen, and then the electrode material is coated on the array electrode screen, and the electrode material is scraped through the array electrode screen to the surface of the electrode base film by a scraper, and the electrode material is printed on the electrode base film to obtain an electrode layer, and the electrode layer is bonded to the surface of the flexible base layer by an adhesive;

[0038] Using an adhesive to bond the frame layer to the surface of the electrode layer;

[0039] The ion gel is mixed with an initiator to obtain an ion gel solution, the ion gel solution is dispensed into the frame layer, and then subjected to ultraviolet curing treatment to obtain an ion hydrogel layer;

[0040] The encapsulation layer is bonded to the surface of the ionic hydrogel layer using an adhesive.

[0041] Currently, most of the existing pressure sensors that can achieve high-resolution pressure sensing are array sensors based on the piezoresistive effect and the piezoceramic effect. This type of sensor responds to the pressure gradient based on the change in resistance or capacitance when subjected to external pressure. Therefore, an external power supply is required to convert this change into a voltage output in order to achieve further acquisition and processing of the sensing signal. The embodiment of the present invention uses a self-powered piezoresistive effect sensor for improvement to achieve lower power consumption. However, most sensors based on the piezoresistive effect currently use a whole-piece structure and array electrodes, which are used for body strain sensing or low-resolution position sensing, and it is difficult to achieve high-resolution pressure sensing applications. This is because the hydrogel sensor array faces two difficult-to-solve problems: anti-crosstalk and array consistency.

[0042] The embodiment of the present invention improves the crosstalk problem of array sensing. The crosstalk problem originates from the conductive paths formed by the wires between the sensing units being connected in parallel, which can easily generate leakage current in other circuits, thereby generating interference signals. However, if each unit is collected separately, there will be problems such as high wire density and insufficient spatial resolution. The embodiment of the present invention adopts the method of screen printing array electrodes, which can achieve high-density electrode printing in a small area, and adopts the structure of measurement / reference pair electrodes. Each sensing unit is individually collected with a measurement electrode, and each reference electrode is connected to a common ground, thereby isolating the crosstalk between signals.

[0043] In addition, the pressure sensor of the embodiment of the present invention is based on the piezoelectric effect. The hydrogen ions ionized by the hydrolysis of the ion gel in the ion hydrogel layer are separated instantaneously under the applied mechanical stress, thereby generating an ion current that can respond to external mechanical pressure. Specifically, when external stress is applied, a pressure gradient will be generated inside the ion gel material, thereby generating a water flux carrying ions and applying fluid dynamics to the ions. The measurement method is to place the test electrode at the center of the sensing point at the pressing position, and place the reference electrode at the edge of the sensing point at the pressing position. When subjected to pressure, the ions inside the ion hydrogel layer diffuse to the reference electrode area under the action of pressure, thereby generating an ion current between the two electrodes, realizing the self-powered function. The pressure sensor provided by the embodiment of the present invention improves the pressure sensing resolution of the self-powered hydrogel device through the design of the array; through the isolation of the screen printing electrode process and the frame layer, the interface bonding stability is improved and the signal crosstalk is reduced, thereby realizing high-quality sensor signal transmission.

[0044] In some embodiments, the electrode substrate film is one of a thermoplastic polyurethane rubber film, a thermoplastic polyester material film, and a polyimide film, and the electrode material is one of a silver paste, a carbon paste, and a conductive polymer.

[0045] In some embodiments, the step of mixing the ion gel with the initiator to obtain the ion gel solution is specifically: dissolving the ion gel pair, the crosslinking agent and the initiator in water, and stirring to obtain the ion gel solution.

[0046] In some embodiments, the ion gel pair is a pair of acrylamide and acrylic acid, acrylonitrile and N-isopropylacrylamide, the initiator is one of 2959 photoinitiator, APS thermal curing agent, LAP photocuring agent, potassium persulfate, and the crosslinking agent is one of isophthalimide, N,N'-methylenebisacrylamide, and polyethylene glycol diacrylate.

[0047] In some embodiments, in the ion gel solution, the concentration of the ion gel pair is 5 wt %-15 wt %, and the concentration of the cross-linking agent is 1 wt %-3 wt %.

[0048] The ratio of ion gel pairs affects the response recovery time of the output voltage. The greater the ratio of ion gel pairs in the ion gel solution, the longer the response recovery time of the voltage under pressure. The smaller the ratio, the shorter the response recovery time of the voltage under pressure. Changes in the cross-linking agent content will affect the flexibility of the ion hydrogel layer. The lower the content, the lower the modulus of the ion hydrogel layer and the easier it is to deform.

[0049] In some embodiments, the mass ratio of acrylic acid to acrylamide is 1:1 to 3:1, and the mass ratio of acrylonitrile to N-isopropylacrylamide is 1:1 to 3:1.

[0050] The mass ratio of acrylic acid to acrylamide affects the hardness of the sensing unit. The greater the hardness, the smaller the voltage output generated under the same pressure.

[0051] In some embodiments, the UV curing treatment is specifically: irradiating with a UV lamp with a wavelength of 365nm-380nm and a power of 20W-25W for 10min-15min.

[0052] In some embodiments, after the frame layer is bonded to the surface of the electrode layer using an adhesive, the method further includes: immersing the bonded flexible substrate layer, electrode layer and frame layer in a benzophenone-ethanol solution for 15 min-20 min, and then performing plasma treatment for 20 s-1 min.

[0053] The embodiment of the present invention improves the array consistency problem in the existing pressure sensor through the design of the ionic hydrogel layer. Most hydrogel sensors are difficult to control the consistency of the array units. This is because the bonding between different array units of the hydrogel and the contact interface is not strong, resulting in inconsistent curing levels. The embodiment of the present invention enhances the hydrophilicity of the gel contact interface through air plasma treatment, and uses benzophenone chemical treatment to achieve bonding between the gel and the contact interface. Finally, the dispensing process is used to improve the consistency of array curing.

[0054] In some embodiments, the thickness of the frame layer is 0.05 cm-2 cm.

[0055] The thickness of the frame layer will directly affect the thickness of the ionic hydrogel layer after curing, and therefore will affect the amplitude of the voltage generated by the pressure sensor. The thinner the thickness, the greater the voltage output, and the thicker the thickness, the smaller the voltage output.

[0056] An embodiment of the present invention provides a pressure sensor, which is prepared by the above-mentioned preparation method.

[0057] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments, and are only for illustrating the present invention but not limiting the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention.

[0058] Example 1

[0059] A pressure sensor, the overall structure of which is shown in FIG. Figure 1 As shown, the preparation method comprises the following steps:

[0060] Step 1: Prepare a flexible substrate layer: Use a 3D printer to print a PLA mold groove of 3×3×0.1 cm, take Ecoflex00-30 precursor and cross-linking agent in a mass ratio of 1:1, mix them, use a glass rod to stir for 5 minutes and then cast them into the mold, vacuum degas for 10 minutes to remove bubbles, and cure at 70°C in a drying oven for 30 minutes before taking out the mold for use.

[0061] Step 2: Prepare the electrode layer: First, prepare the electrode screen, fix the prefabricated array electrode screen on the screen printer, take a 5×5cm (length×width) TPU film (electrode base film), place the TPU film and align the position and fix it, where the TPU film is located below the array electrode screen, pour a certain amount of stretchable silver paste (filling material) on the array electrode screen, and use a special brush to scrape the silver paste through the array electrode screen to the surface of the TPU film. After printing, use an oven at 110℃ to dry for 20 minutes. The screen-printed electrode pattern is divided into a sensing part and an FPC connection part. In the sensing part, since it is an electrode designed for a 4×4 array, each sensing unit corresponds to two point electrodes (positive and negative), the electrode diameter is 1mm, and the center distance between the electrodes is 7mm. Each electrode extends to one end of the TPU film as an FPC connection part for extracting the sensing signal. The positive electrode serves as the subsequent voltage collection end, and the negative electrode is connected as a common ground end. The electrode width of the FPC connection part is 1.5mm, and the electrode center distance is 2.0mm. The electrode pattern diagram is as follows Figure 2 shown.

[0062] Step 3: Prepare the frame layer: Use a 3D printer to print a 3×3×0.1cm PLA mold. There are 4×4 cylindrical protrusions in the mold grooves to correspond to the 4×4 sensor array points. Take Ecoflex00-30 and mix and cast it in the mold according to the method in step 1. Vacuum degassing for 10 minutes to remove bubbles, and then cure it in a drying oven at 70℃ for 30 minutes before taking it out. Use Smooth-On release agent to demold it for later use. The schematic diagram of the frame layer is as follows Figure 3 shown.

[0063] Step 4: Bonding and surface treatment of the flexible substrate layer, electrode layer and frame layer: The flexible substrate layer, electrode layer and frame layer are bonded with sil poxy adhesive, and then cured at room temperature for 4 hours to form a stable adhesion effect. After the adhesive is cured, it is soaked in 5wt% benzophenone-ethanol solution for 15 minutes to facilitate chemical bonding between Ecoflex and poly (acrylamide-acrylic acid) hydrogel in step 5 to improve the interface stability, and then PLASMA plasma treatment is performed for 20s to enhance the hydrophilicity of the interface. Combined with the actual picture as shown Figure 4 shown.

[0064] Step 5: Preparation of ionic hydrogel layer: 0.75g acrylic acid, 0.75g acrylamide, 0.015g isophthalimide (MBAA), 8.485g water and 0.03g 2959 photoinitiator were mixed, ultrasonicated for 10 minutes, and prepared into 10mL poly (acrylamide-acrylic acid) solution (ionic gel solution). The ionic gel solution was sucked with a pipette and then dispensed into the frame layer to ensure the consistency of the solution content of each sensor unit, and then irradiated with a UV lamp with a wavelength of 365nm and a power of 25W for 15 minutes to completely cure.

[0065] Step 6: Preparation based on the encapsulation layer: The size, thickness and process operation of the encapsulation layer are the same as those in step 1.

[0066] Step 7: Encapsulation: The encapsulation layer and the ion gel layer are bonded with sil poxy adhesive to improve the water retention of the hydrogel and extend the service life of the device. After bonding, they are cured at room temperature for 4 hours to form a stable adhesion effect to obtain the pressure sensor. The overall physical picture is as follows Figure 5 shown.

[0067] Step 8: Leading out the sensing signal: Use ACF electrical tape to stick to the FPC connection part of the TPU electrode layer, and use 200℃ hot pressing for 1 minute to achieve reliable electrical connection. And ACF tape has anisotropic conductivity and will not cause short circuits between conductive paths.

[0068] The layered decomposition structure of the pressure sensor prepared in Example 1 is shown in FIG. Figure 6 As shown, 1 is a packaging layer, 2 is an ion gel layer, 3 is a frame layer, 4 is a connecting portion between the FPC and the electrode layer, 5 is a connecting portion between the FPC and the adapter board, 6 is an electrode layer, 7 is a negative electrode on the electrode layer, 8 is a positive electrode on the electrode layer, and 9 is a flexible substrate layer.

[0069] Example 2

[0070] This embodiment provides a preparation method for a pressure sensor, which is basically the same as the preparation method of Embodiment 1, except that the thickness of the frame layer in step 3 is 0.05 cm.

[0071] Example 3

[0072] This embodiment provides a preparation method for a pressure sensor, which is basically the same as the preparation method of Embodiment 1, except that the thickness of the frame layer in step 3 is 1.5 cm.

[0073] Example 4

[0074] This embodiment provides a preparation method for a pressure sensor, which is basically the same as the preparation method of Embodiment 1, except that the thickness of the frame layer in step 3 is 2 cm.

[0075] Example 5

[0076] This embodiment provides a preparation method of a pressure sensor, which is basically the same as the preparation method of Example 1, except that in step 5, 0.5 g of acrylic acid, 0.5 g of acrylamide, 0.05 g of isophthalic acid imide (MBAA), and 9.85 g of water are taken to prepare a 10 wt % poly (acrylamide-acrylic acid) solution.

[0077] Example 6

[0078] This embodiment provides a preparation method of a pressure sensor, which is basically the same as the preparation method of Example 1, except that in step 5, 1 g of acrylic acid, 1 g of acrylamide, 0.01 g of isophthalic acid imide (MBAA), and 9.79 g of water are taken to prepare a 20 wt % poly (acrylamide-acrylic acid) solution.

[0079] Example 7

[0080] This embodiment provides a preparation method of a pressure sensor, which is basically the same as the preparation method of Example 1, except that in step 5, 1.5 g of acrylic acid, 1.5 g of acrylamide, 0.3 g of isophthalic acid imide (MBAA), and 6.7 g of water are taken to prepare a 30 wt % poly (acrylamide-acrylic acid) solution.

[0081] In addition, in order to meet the needs of flexible device preparation, the embodiments of the present invention all use a flexible substrate and packaging layer, a flexible electrode layer, a flexible frame layer, and an ion hydrogel layer. The overall device thickness is within 5 mm, and the flexibility is guaranteed. Compared with the common ion hydrogel sensor, the ion gel monomer material of the present invention can hydrolyze and ionize to produce an ion current that responds to the pressure gradient, and has self-powered capability. Compared with the application limitations of the existing self-powered hydrogel pressure sensing technology with lower resolution, the present invention realizes high-resolution pressure sensing in a small area through the form of a sensor array.

[0082] The pressure sensor prepared by the present invention does not require an external power supply. The FPC can be connected to the conversion board, and the signal can be led out to a multi-channel acquisition system such as an NI acquisition board, Arduino, PBC acquisition circuit, etc. by using a Dupont line to realize the acquisition of voltage signals. The collected signal is programmed in data analysis software such as LABVIEW, Python, MATLAB, etc. to realize pressure positioning visualization. The intensity of the voltage signal can be controlled by adjusting the acrylic acid content and thickness in the hydrogel.

[0083] As an application, the FPC is connected to the adapter board, and the signal is led out to the NI-6268 acquisition board using the DuPont line. The acquisition board can realize the single-ended acquisition of 16 voltage signals. The collected signals are imported into LABVIEW to write the pressure positioning visualization program. The program flow chart is as follows Figure 7 As shown in the figure. When a finger presses the surface of the sensor device, the visualization program will also display the specific point on the pressing array and the stress magnitude. At the same time, due to the flexibility of the device itself, high-resolution pressure positioning can be achieved in different scenarios, such as curved surfaces. Figure 8 shown.

[0084] The performance of the pressure sensors prepared in Examples 1-7 was tested by connecting the sensor signal lead wires to an electrometer, performing a constant load pressure test using a universal testing machine, and observing the voltage amplitude and duration of the outputs of different samples.

[0085] Examples 1-4 compare the voltage output curves of pressure sensors with different frame layer thicknesses. Fig. 9 Examples 1, 5-7 compare the response recovery curves of pressure sensors with different ion gel concentrations under the same pressure. The results are shown in Fig.10 shown.

[0086] It should be understood that the application of the present invention is not limited to the above examples. For ordinary technicians in this field, improvements or changes can be made based on the above description. All these improvements and changes should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A method for preparing a pressure sensor, characterized in that: The preparation method comprises the following steps: Providing a flexible substrate layer, a frame layer and a packaging layer; The array electrode screen and the electrode base film are fixed to the corresponding positions of the screen printer respectively, the electrode base film is located below the array electrode screen, and then the electrode material is coated on the array electrode screen, and the electrode material is scraped through the array electrode screen to the surface of the electrode base film by a scraper, and the electrode material is printed on the electrode base film to obtain an electrode layer, and the electrode layer is bonded to the surface of the flexible base layer by an adhesive; Using an adhesive to bond the frame layer to the surface of the electrode layer; The ion gel is mixed with an initiator to obtain an ion gel solution, the ion gel solution is dispensed into the frame layer, and then subjected to ultraviolet curing treatment to obtain an ion hydrogel layer; The encapsulation layer is bonded to the surface of the ionic hydrogel layer using an adhesive.

2. The method for preparing a pressure sensor according to claim 1, characterized in that: The electrode substrate film is one of a thermoplastic polyurethane rubber film, a thermoplastic polyester material film, and a polyimide film, and the electrode material is one of a silver paste, a carbon paste, and a conductive polymer.

3. The method for preparing a pressure sensor according to claim 1, characterized in that: The step of mixing the ion gel and the initiator to obtain the ion gel solution is specifically: dissolving the ion gel pair, the crosslinking agent and the initiator in water, stirring, and obtaining the ion gel solution.

4. The method for preparing a pressure sensor according to claim 3, characterized in that: The ion gel pair is a pair of acrylamide and acrylic acid, acrylonitrile and N-isopropylacrylamide, the initiator is one of 2959 photoinitiator, APS thermal curing agent, LAP photocuring agent, and potassium persulfate, and the crosslinking agent is one of isophthalimide, N,N'-methylenebisacrylamide, and polyethylene glycol diacrylate.

5. The method for preparing a pressure sensor according to claim 3, characterized in that: In the ion gel solution, the concentration of the ion gel pair is 5wt%-15wt%, and the concentration of the cross-linking agent is 1wt%-3wt%.

6. The method for preparing a pressure sensor according to claim 4, characterized in that: The mass ratio of the acrylic acid to acrylamide is 1:1 to 3:1, and the mass ratio of the acrylonitrile to N-isopropylacrylamide is 1:1 to 3:

1.

7. The method for preparing a pressure sensor according to claim 1, characterized in that: The ultraviolet curing treatment is specifically: using an ultraviolet lamp with a wavelength of 365nm-380nm and a power of 20W-25W to irradiate for 10min-15min.

8. The method for preparing a pressure sensor according to claim 1, characterized in that: After the frame layer is bonded to the surface of the electrode layer using an adhesive, the method further includes the steps of: immersing the bonded flexible substrate layer, electrode layer and frame layer in a benzophenone-ethanol solution for 15 minutes to 20 minutes, and then performing plasma treatment for 20 seconds to 1 minute.

9. The method for preparing a pressure sensor according to claim 1, characterized in that: The thickness of the frame layer is 0.05cm-2cm.

10. A pressure sensor, characterized in that: The pressure sensor is prepared by the preparation method according to any one of claims 1 to 9.

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