Double-layer ion enhanced high-range high-linearity fabric-based flexible pressure sensor and preparation method thereof

Abstract

The invention discloses a double-layer ion enhanced high-range high-linearity fabric-based flexible pressure sensor and a preparation method thereof, and belongs to the technical field of underwater flexible pressure sensors. The flexible pressure sensor comprises a first composite layer and a second composite layer, and a porous material is arranged between the first composite layer and the second composite layer. The first composite layer and the second composite layer are symmetrically arranged on the two sides of the porous material; the first composite layer sequentially comprises a flexible substrate, a nickel cloth electrode and an ionic membrane layer from outside to inside, the flexible substrate is formed by thermal bonding of a fabric and a TPU film, and the fabric is located on the outer side; the ionic membrane layer is formed by coating a nickel cloth electrode with a first ionic solution in a silk-screen printing manner; and thermally bonding the first composite layer, the porous material and the second composite layer, and wrapping the outer sides of the first composite layer and the second composite layer with PDMS to obtain the flexible pressure sensor. The flexible pressure sensor has the advantages of ultrahigh measuring range, high linearity, high sensitivity and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of underwater flexible pressure sensors, and in particular to a double-layer ion-enhanced high-range and high-linearity fabric-based flexible pressure sensor and a preparation method thereof. Background Art

[0002] Ocean pressure is a key indicator that reflects a variety of information about the ocean's morphology, structural characteristics, and dynamic behavior. Accurately monitoring this pressure is essential for monitoring marine ecosystems, managing shipping routes, and supporting marine fisheries. Traditional ocean pressure sensors are limited by their rigid structure and have difficulty capturing tiny pressure changes; and the sensor often requires the protection of a pressure chamber to withstand the greater hydrostatic pressure in the ocean, which also limits its flexibility in integration with many platforms and cannot adapt to some application scenarios.

[0003] In recent years, flexible pressure sensors have achieved great development due to their high sensitivity and adaptability. These sensors can be seamlessly integrated into various platforms, including ocean buoys and underwater robots, to achieve high-precision and large-scale ocean pressure monitoring. Moreover, flexible pressure sensors based on soft materials have broad application prospects in deep-sea sensing due to their incompressibility under large hydrostatic pressures and the potential to eliminate pressure cavities. However, the research on the measurement range of these flexible pressure sensors to date is mostly limited to the order of a few kPa, rarely reaching the MPa range, and it is even more difficult to maintain high accuracy in the MPa range, so it is difficult to extend it to deep-sea environments. Summary of the invention

[0004] Based on the above technical problems, the present invention proposes a double-layer ion-enhanced high-range and high-linearity fabric-based flexible pressure sensor and a preparation method thereof.

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

[0006] A double-layer ion-enhanced high-range high-linearity fabric-based flexible pressure sensor, comprising a first composite layer and a second composite layer, wherein a porous material is disposed between the first composite layer and the second composite layer;

[0007] The first composite layer and the second composite layer are symmetrically arranged on both sides of the porous material;

[0008] The first composite layer includes a flexible substrate, a nickel cloth electrode and an ion membrane layer from the outside to the inside, wherein the flexible substrate is made by thermally bonding a fabric and a TPU film, and the fabric is on the outside; the ion membrane layer is formed by coating the first ion solution on the nickel cloth electrode by screen printing;

[0009] The first ionic solution is prepared by the following steps: adding thermoplastic polyurethane elastomer particles into N,N-dimethylformamide, heating and stirring, and dropping ionic liquid, and then adding carbon nanotubes, hexagonal boron nitride or silicon dioxide, and fully dissolving to obtain;

[0010] The first composite layer, the porous material and the second composite layer are thermally bonded, and then the outer sides of the first composite layer and the second composite layer are wrapped with PDMS to obtain the flexible pressure sensor.

[0011] Preferably, the porous material is fully immersed in the second ion solution and then sandwiched between the first composite layer and the second composite layer; the second ion solution is prepared by the following steps: adding the ionic liquid into deionized water and mixing well.

[0012] Preferably, the ionic liquid is 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt; and the porous material is polyurethane sponge.

[0013] Preferably, a gold layer is pre-sputtered on one side of the screen-printed ion membrane layer of the nickel cloth electrode.

[0014] The present invention also provides a method for preparing the double-layer ion-enhanced high-range and high-linearity fabric-based flexible pressure sensor as described above, comprising the following steps:

[0015] (1) Thermally bonding the fabric and TPU film to obtain a flexible substrate;

[0016] (2) Assembling a nickel cloth electrode on the flexible substrate and on the side of the TPU film;

[0017] (3) sputtering a gold layer on the surface of the nickel cloth electrode, and then screen printing an ion membrane layer to assemble the first composite layer;

[0018] (4) Repeat steps (1) to (3) to assemble a second composite layer;

[0019] (5) selecting a porous material and fully immersing the porous material in a second ion solution to obtain a soaked porous material;

[0020] (6) sandwiching the soaked porous material between the first composite layer and the second composite layer, thermally bonding them to form a whole, and then completely wrapping them with PDMS to obtain the flexible pressure sensor;

[0021] In step (3), the first ion solution used for screen printing the ion membrane layer is prepared by the following steps: adding thermoplastic polyurethane elastomer particles to N,N-dimethylformamide, heating and stirring, and dropping ionic liquid, and then adding carbon nanotubes, hexagonal boron nitride or silicon dioxide, stirring and dissolving, and obtaining;

[0022] In step (5), the second ionic solution is prepared by the following steps: adding the ionic liquid into deionized water and mixing well.

[0023] Preferably, in step (2): the nickel cloth electrode is an unplated high-purity nickel cloth or a gold-plated, platinum-plated, copper-plated, or silver-plated high-purity nickel cloth.

[0024] Preferably, in step (3): based on 2 g of thermoplastic polyurethane elastomer particles, the amount of N,N-dimethylformamide is 3-6 ml, the amount of ionic liquid is 0.8-1.2 ml, and the amount of carbon nanotubes, hexagonal boron nitride or silicon dioxide is 0.1-0.3 g;

[0025] The heating and stirring temperature is controlled at 90-120°C, and the heating and stirring time is 30-45 minutes; the sufficient stirring and dissolving time is 2-3 hours.

[0026] Preferably, the ionic liquid is 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, the mass ratio of the ionic liquid to deionized water in the second ionic solution is 1:5-1:20; and the porous material is polyurethane sponge.

[0027] The total thickness of the flexible pressure sensor does not exceed 0.5 mm; it can measure data of 0-400 meters water depth; the minimum detection line is 0.2 grams and the response time is 20 milliseconds.

[0028] The beneficial technical effects of the present invention are as follows:

[0029] The total thickness of the fabric-based flexible pressure sensor of the present invention does not exceed 0.5 mm, and it can measure underwater water depth data of 0-400 meters. It has the advantages of ultra-high range, high linearity, high sensitivity, etc. It can be conformal with underwater unmanned equipment, which is of great significance for achieving high-precision and large-scale ocean pressure monitoring.

[0030] The flexible pressure sensor of the present invention realizes double-layer ion enhancement by screen-printing an ion membrane layer on the electrode and sandwiching a porous polyurethane sponge soaked in ionic liquid in the middle, thereby effectively improving the sensitivity and detection range of the sensor, especially ensuring high sensitivity in deeper underwater environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 An overall exploded view of a double-layer ion-enhanced high-range and high-linearity fabric-based flexible pressure sensor according to an embodiment of the present invention;

[0032] Figure 2 This is a flow chart for preparing a double-layer ion-enhanced high-range and high-linearity fabric-based flexible pressure sensor in an embodiment of the present invention;

[0033] Figure 3It is a flowchart of a method for preparing a double-layer ion-enhanced high-range and high-linearity fabric-based flexible pressure sensor in an embodiment of the present invention;

[0034] Figure 4 This is a performance comparison diagram of the flexible pressure sensor obtained by changing the concentration of different ionic liquids in the second ionic solution according to an embodiment of the present invention;

[0035] Figure 5 The lowest detection line diagram of the double-layer ion-enhanced high-range and high-linearity fabric-based flexible pressure sensor prepared in an embodiment of the present invention;

[0036] Figure 6 This is a response time diagram of a double-layer ion-enhanced high-range and high-linearity fabric-based flexible pressure sensor manufactured according to an embodiment of the present invention;

[0037] Figure 7 This is a long-term cycle diagram of 4650 times of the double-layer ion-enhanced high-range and high-linearity fabric-based flexible pressure sensor produced in an embodiment of the present invention under a pressure of 1 MPa;

[0038] Figure 8 This is an experimental test diagram of the underwater pressure 0-5MPa of the double-layer ion-enhanced high-range and high-linearity fabric-based flexible pressure sensor made in an embodiment of the present invention;

[0039] Fig. 9 This is a performance comparison diagram of the double-layer ion-enhanced high-range and high-linearity fabric-based flexible pressure sensor made in an embodiment of the present invention and the existing flexible pressure sensor;

[0040] Fig.10 This is a sensitivity curve diagram of the double-layer ion-enhanced high-range and high-linearity fabric-based flexible pressure sensor produced in an embodiment of the present invention.

[0041] In the figure: 1-porous material, 2-nickel cloth electrode, 3-ion membrane layer, 4-textile, 5-TPU film, 6-gold layer. DETAILED DESCRIPTION

[0042] The invention discloses a double-layer ion-enhanced high-range and high-linearity fabric-based flexible pressure sensor and a preparation method thereof. The flexible pressure sensor comprises a flexible substrate formed by thermal bonding of a TPU film and a fabric on one side; a nickel cloth electrode is assembled on the flexible substrate, and the nickel cloth electrode can be cut into different shapes (such as circle, rectangle, triangle, etc.) by a small ultraviolet laser cutting machine according to actual needs; then gold is sputtered on the nickel cloth electrode by a high vacuum magnetron ion sputtering instrument, which can improve the underwater performance of the pressure sensor; the prepared ion solution is screen-printed into an ion layer; the other side of the flexible pressure sensor is prepared by the same method, and finally a porous polyurethane sponge is sandwiched between the two sides, and the porous polyurethane sponge needs to be fully soaked in the ion solution and then taken out. Finally, it is wrapped with PDMS to obtain a double-layer ion-enhanced high-range and high-linearity fabric-based flexible pressure sensor. The flexible pressure sensor has an ultra-high range, high linearity, and high sensitivity, and can be conformal with underwater unmanned equipment, which is of great significance for realizing high-precision and large-scale ocean pressure monitoring.

[0043] The present invention will be further described below in conjunction with the accompanying drawings and specific implementations.

[0044] Example 1

[0045] like Figure 1 As shown, a double-layer ion-enhanced high-range high-linearity fabric-based flexible pressure sensor includes a first composite layer and a second composite layer, and a porous material 1 is arranged between the first composite layer and the second composite layer. The first composite layer and the second composite layer are symmetrically arranged on both sides of the porous material. The first composite layer includes a flexible substrate, a nickel cloth electrode 2 and an ion membrane layer 3 from the outside to the inside, and the flexible substrate is made by thermal bonding of a fabric 4 and a TPU film 5, and the fabric 4 is on the outermost side. The first composite layer, the porous material and the second composite layer are thermally bonded to form a whole, and then placed in a mold, and the outer sides of the first composite layer and the second composite layer are wrapped with PDMS to obtain the flexible pressure sensor.

[0046] The above-mentioned ion membrane layer is formed by coating the first ion solution on the nickel cloth electrode 2 by screen printing. The first ion solution is prepared by the following steps: 2g of thermoplastic polyurethane elastomer particles (TPU) are added to 5ml of N,N-dimethylformamide, magnetic beads are added, heated to 100 degrees Celsius, and magnetically stirred at this temperature for 30 minutes; 1ml of ionic liquid (1-ethyl-3-methylimidazole bistrifluoromethanesulfonyl imide salt) is added dropwise during the stirring process, and 0.1g of carbon nanotubes is added after magnetic stirring for a period of time, and magnetic stirring is continued for 2 hours to fully dissolve it. The addition of carbon nanotubes can effectively increase the stiffness of TPU and reduce hysteresis. In addition, it can significantly prevent the material loss of the ion membrane when the sensor is under pressure.

[0047] The porous material 1 is fully immersed in the second ion solution and then sandwiched between the first composite layer and the second composite layer. The second ion solution is prepared by the following steps: adding ionic liquid to deionized water and mixing well.

[0048] The ionic liquid is 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt; and the porous material is polyurethane sponge.

[0049] Example 2

[0050] A double-layer ion-enhanced high-range and high-linearity fabric-based flexible pressure sensor has a basic structure similar to that of Example 1, except that a gold layer 6 is pre-sputtered on one side of the screen-printed ion membrane layer of the nickel cloth electrode to further improve the sensitivity and stability of the pressure sensor in underwater depth detection.

[0051] The total thickness of the flexible pressure sensor of the present invention does not exceed 0.5 mm, and it can measure data of 0-400 meters of water depth. The flexible pressure sensor has the advantages of ultra-high range, high linearity, high sensitivity, high stability, etc., and can be conformal with underwater unmanned equipment, which is of great significance for realizing high-precision and large-scale ocean pressure monitoring.

[0052] The flexible pressure sensor can further transmit data to the device via a Bluetooth module.

[0053] In the above-mentioned flexible pressure sensor, the outermost layer is made of PDMS (polydimethylsiloxane, also known as dimethyl silicone oil) poured into the mold. It looks like a colorless, transparent and extremely high viscosity liquid or silicone. It is odorless, highly transparent, and has the advantages of heat resistance, cold resistance, small viscosity change with temperature, waterproofness, small surface tension and good thermal conductivity. PDMS is used to wrap the flexible sensor, so that the corresponding structure has good waterproof and corrosion resistance.

[0054] Example 3

[0055] like Figure 2 , Figure 3 As shown, a method for preparing a double-layer ion-enhanced high-range and high-linearity fabric-based flexible pressure sensor comprises the following steps:

[0056] (1) The fabric 4 and the TPU film 5 are thermally bonded to obtain a flexible substrate. The fabric can be made of natural fibers such as cotton and linen, or synthetic fibers such as polyester. The fabric can be cut into any desired shape by a small UV laser cutting machine.

[0057] (2) Assemble a nickel cloth electrode 2 on the flexible substrate and on one side of the TPU film 5. The nickel cloth electrode is similar to an adhesive tape, and one side of the nickel cloth electrode can be directly bonded to the TPU film.

[0058] (3) Gold is sputtered on the surface of the nickel cloth electrode 2 by using a high vacuum magnetron ion sputtering apparatus, and then the ion membrane layer 3 is screen-printed to assemble and obtain the first composite layer.

[0059] (4) Repeat steps (1) to (3) to assemble a second composite layer.

[0060] (5) Select the porous material 1, and fully immerse it in the second ion solution to obtain the immersed porous material.

[0061] (6) The soaked porous material is sandwiched between the first composite layer and the second composite layer, thermally bonded to form a whole, and then completely wrapped with PDMS to obtain the flexible pressure sensor.

[0062] In the above step (2): the nickel cloth electrode is a non-plated high-purity nickel cloth.

[0063] In the above step (3), the first ion solution used for screen-printed ion membrane layer is prepared by the following steps: 2g of thermoplastic polyurethane elastomer particles (TPU) are added to 5ml of N,N-dimethylformamide, magnetic beads are added, heated to 100 degrees Celsius, and magnetically stirred at this temperature for 30 minutes. During the stirring process, 1ml of ionic liquid (1-ethyl-3-methylimidazole bis(trifluoromethanesulfonyl)imide) is added dropwise, and after magnetic stirring for a period of time, 0.1g of carbon nanotubes is added, and magnetic stirring is continued for 2 hours to fully dissolve. The addition of carbon nanotubes and the like effectively increases the stiffness of TPU and reduces hysteresis. In addition, it can significantly prevent the material loss of the ion membrane when the sensor is under pressure.

[0064] In step (5), the second ion solution is prepared by the following steps: adding the ionic liquid into deionized water and mixing well. The mass ratio of the ionic liquid to the deionized water is 1:10.

[0065] In step (6), the entire sensor is first thermally bonded and then the entire sensor is wrapped with PDMS.

[0066] The porous material 1 is made of polyurethane sponge.

[0067] The flexible pressure sensor of the present invention realizes double-layer ion enhancement by screen-printing an ion membrane layer on the electrode and sandwiching a porous polyurethane sponge soaked in ionic liquid in the middle, thereby effectively improving the sensitivity and detection range of the sensor, especially ensuring that it still has high sensitivity in deeper underwater environments. The total thickness of the flexible pressure sensor is no more than 0.5 mm; it can measure data of 0-400 meters of water depth; the minimum detection line is 0.2 grams, and the response time is 20 milliseconds.

[0068] Example 4

[0069] The preparation method is the same as that of Example 3. The difference is that:

[0070] In step (2): the nickel cloth electrode is a platinum-plated high-purity nickel cloth to further increase the service life of the nickel cloth electrode in water.

[0071] In step (3), the first ion solution used for screen printing the ion membrane layer is prepared by the following steps: 2 g of thermoplastic polyurethane elastomer particles (TPU) are added to 4 ml of N,N-dimethylformamide, magnetic beads are added, heated to 120 degrees Celsius, and magnetically stirred at this temperature for 40 minutes. During the stirring process, 1.2 ml of ionic liquid (1-ethyl-3-methylimidazole bis(trifluoromethanesulfonyl)imide) is added dropwise, and after magnetic stirring for a period of time, 0.2 g of hexagonal boron nitride is added, and magnetic stirring is continued for 3 hours to fully dissolve it.

[0072] Example 5

[0073] The preparation method is the same as that of Example 3, except that:

[0074] In step (5), when preparing the second ionic solution, the mass ratio of the ionic liquid to the deionized water is adjusted to 1:5, the mass ratio of the ionic liquid to the deionized water is adjusted to 1:15, and the mass ratio of the ionic liquid to the deionized water is adjusted to 1:20.

[0075] like Figure 4 As shown, the porous polyurethane sponge soaked in a mixed solution of deionized water and ionic liquid in different concentration ratios was tested, and it was found that a concentration ratio of 1:10 made the flexible pressure sensor perform best.

[0076] In the above embodiment, the nickel cloth electrode can be cut into different shapes by a small UV laser cutting machine, such as circle, rectangle, triangle, etc. Of course, the porous polyurethane sponge can also be cut into a shape compatible with the nickel cloth electrode by a small UV laser cutting machine.

[0077] The flexible pressure sensor of the present invention is an ionization pressure sensor (also known as supercapacitive sensing), the principle of which is the double-layer effect formed by ion-sensitive materials with high ion density and electrodes. Under pressure load, the contact area and spacing (nanometer order) between the sensitive material and the electrode change, resulting in changes in the interface capacitance. Compared with traditional capacitive sensors, the ionization sensor based on the double layer of the present invention increases the capacitance value by more than 1,000 times, which can greatly improve the sensitivity and detection range of the sensor. In addition, the electrostatic interference carried by the device itself during the signal acquisition process will affect the sensitivity of the sensor, while the ionization sensor has the advantages of high signal-to-noise ratio and reduced parasitic noise and environmental electromagnetic field interference.

[0078] The porous polyurethane sponge is sandwiched in the sensor of the present invention, which can effectively increase the range of water depth detection and prevent the flexible sensor from being squeezed when placed in water and losing its function due to the inability to form a compressed space. At the same time, on this basis, the porous polyurethane sponge is soaked in ionic liquid and an ion membrane is screen-printed on the electrode to improve the sensitivity of the flexible sensor, thereby ensuring that it still has high sensitivity in a deeper underwater environment.

[0079] The performance test of the double-layer ion-enhanced high-range and high-linearity fabric-based flexible pressure sensor obtained by the present invention is carried out, and the results are as follows: Figure 5-Figure 9 shown.

[0080] like Figure 5 As shown in the figure, the lowest detection line of the flexible pressure sensor is 0.2 grams, which means that the sensor is extremely sensitive and can capture tiny pressure changes and achieve high-precision measurement. Figure 6 As shown in Figure 1, the response time of the flexible pressure sensor is 20 milliseconds, and it can even detect tiny vibration signals underwater. Figure 7 As shown in Figure 2, the flexible pressure sensor can maintain consistency and stability after 4650 long-term cycles at a pressure of 1 MPa. Figure 8 As shown, the flexible pressure sensor was tested under simulated underwater pressure of 0-5MPa, indicating that the flexible pressure sensor can measure data at a water depth of 0-400 meters, and can further transmit the data to the device through a Bluetooth module.

[0081] Fig. 9 This is a performance comparison chart of the double-layer ion-enhanced high-range and high-linearity fabric-based flexible pressure sensor made in the embodiment of the present invention and the existing flexible pressure sensor. In the figure, reference 1 is a capacitive pressure sensor inspired by the biologically inspired KAPOK structure, with a wide detection range and high sensitivity, and the highest sensitivity is 2.38kPa -1 , response range 10kPa; Reference 2 is a rugged, self-repairing, high-sensitivity pressure sensor based on insertion, with a maximum sensitivity of 0.125kPa -1 , response range 700kPa. Fig. 9 As shown, by comparing the flexible pressure sensor with the existing conventional flexible pressure sensors, it can be seen that the sensitivity and the pressure range that the flexible pressure sensor can withstand are better than those of the existing conventional flexible pressure sensors, especially the pressure range that can be withstand is particularly outstanding, thereby verifying that the flexible pressure sensor of the present invention has the characteristics of high sensitivity and high range.

[0082] Fig.10This is a sensitivity curve of the double-layer ion-enhanced high-range high-linearity fabric-based flexible pressure sensor made in an embodiment of the present invention. The three stages in the figure have extremely high linearity, up to 0.999. High linearity means more stability and can better predict the value of a certain depth to be reached later.

[0083] The parts not mentioned in the above methods can be realized by adopting or drawing on existing technologies.

[0084] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any improvements, equivalent substitutions, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A double-layer ion-enhanced high-range and high-linearity fabric-based flexible pressure sensor, characterized in that: It includes a first composite layer and a second composite layer, wherein a porous material is disposed between the first composite layer and the second composite layer; The first composite layer and the second composite layer are symmetrically arranged on both sides of the porous material; The first composite layer includes a flexible substrate, a nickel cloth electrode and an ion membrane layer from the outside to the inside, wherein the flexible substrate is made by thermally bonding a fabric and a TPU film, and the fabric is on the outside; the ion membrane layer is formed by coating the first ion solution on the nickel cloth electrode by screen printing; The first ionic solution is prepared by the following steps: adding thermoplastic polyurethane elastomer particles into N,N-dimethylformamide, heating and stirring, and dropping ionic liquid, and then adding carbon nanotubes, hexagonal boron nitride or silicon dioxide, and fully dissolving to obtain; The first composite layer, the porous material and the second composite layer are thermally bonded, and then the outer sides of the first composite layer and the second composite layer are wrapped with PDMS to obtain the flexible pressure sensor.

2. According to claim 1, a double-layer ion-enhanced high-range and high-linearity fabric-based flexible pressure sensor is characterized in that: The porous material is fully immersed in the second ion solution and then sandwiched between the first composite layer and the second composite layer; the second ion solution is prepared by the following steps: adding ionic liquid into deionized water and mixing well.

3. According to claim 2, a double-layer ion-enhanced high-range high-linearity fabric-based flexible pressure sensor is characterized in that: The ionic liquid is 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt; and the porous material is polyurethane sponge.

4. According to claim 1, a double-layer ion-enhanced high-range high-linearity fabric-based flexible pressure sensor is characterized by: A gold layer is pre-sputtered on one side of the screen-printed ion membrane layer of the nickel cloth electrode.

5. The double-layer ion-enhanced high-range and high-linearity fabric-based flexible pressure sensor according to claim 1, characterized in that: The total thickness of this flexible pressure sensor does not exceed 0.5 mm; it can measure data from 0-400 meters of water depth.

6. The method for preparing a double-layer ion-enhanced high-range and high-linearity fabric-based flexible pressure sensor as described in any one of claims 1 to 5, characterized in that The following steps are involved: (1) Thermally bonding the fabric and TPU film to obtain a flexible substrate; (2) Assembling a nickel cloth electrode on the flexible substrate and on the side of the TPU film; (3) sputtering a gold layer on the surface of the nickel cloth electrode, and then screen printing an ion membrane layer to assemble the first composite layer; (4) Repeat steps (1) to (3) to assemble a second composite layer; (5) selecting a porous material and fully immersing the porous material in a second ion solution to obtain a soaked porous material; (6) sandwiching the soaked porous material between the first composite layer and the second composite layer, thermally bonding them to form a whole, and then completely wrapping them with PDMS to obtain the flexible pressure sensor; In step (3), the first ion solution used for screen printing the ion membrane layer is prepared by the following steps: adding thermoplastic polyurethane elastomer particles to N,N-dimethylformamide, heating and stirring, and dropping ionic liquid, and then adding carbon nanotubes, hexagonal boron nitride or silicon dioxide, stirring and dissolving, and obtaining; In step (5), the second ionic solution is prepared by the following steps: adding the ionic liquid into deionized water and mixing well.

7. The method for preparing a double-layer ion-enhanced high-range and high-linearity fabric-based flexible pressure sensor according to claim 6, characterized in that: In step (2): the nickel cloth electrode is an unplated high-purity nickel cloth or a gold-plated, platinum-plated, copper-plated, or silver-plated high-purity nickel cloth.

8. The method for preparing a double-layer ion-enhanced high-range and high-linearity fabric-based flexible pressure sensor according to claim 6, characterized in that: In step (3): based on 2 g of thermoplastic polyurethane elastomer particles, the amount of N,N-dimethylformamide is 3-6 ml, the amount of ionic liquid is 0.8-1.2 ml, and the amount of carbon nanotubes, hexagonal boron nitride or silicon dioxide is 0.1-0.3 g; The heating and stirring temperature is controlled at 90-120°C, and the heating and stirring time is 30-45 minutes; the sufficient stirring and dissolving time is 2-3 hours.

9. The method for preparing a double-layer ion-enhanced high-range and high-linearity fabric-based flexible pressure sensor according to claim 6, characterized in that: The ionic liquid is 1-ethyl-3-methylimidazole bis(trifluoromethanesulfonyl)imide salt, the mass ratio of the ionic liquid to deionized water in the second ionic solution is 1:5-1:20; and the porous material is polyurethane sponge.

10. The method for preparing a double-layer ion-enhanced high-range and high-linearity fabric-based flexible pressure sensor according to claim 6, characterized in that: The total thickness of the flexible pressure sensor does not exceed 0.5 mm; it can measure water depth data from 0 to 400 meters; The minimum detection line is 0.2g and the response time is 20ms.

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