Pressure sensor based on all-solid-state flexible organic electrochemical transistor and preparation method

Abstract

The invention relates to a pressure sensor based on an all-solid-state flexible organic electrochemical transistor and a preparation method, the pressure sensor comprises a PET substrate layer, a source electrode, a drain electrode, an organic semiconductor layer, a solid electrolyte layer and a gate electrode, and the source electrode and the drain electrode are arranged on the PET substrate layer at an interval; the organic semiconductor layer is positioned on the source electrode and the drain electrode, and is positioned on the PET substrate layer between the source electrode and the drain electrode; the solid electrolyte layer is located on the organic semiconductor layer; the gate electrode is located on the solid electrolyte layer, a pyramid array structure is arranged on the side, facing the solid electrolyte layer, of the gate electrode, and a plurality of pyramids are distributed at intervals in the pyramid array structure. According to the embodiment of the invention, the pressure sensor with low-voltage driving, high-sensitivity response and excellent stability is realized, the problems of high working voltage, easy leakage of liquid electrolyte and weak output signal of a flexible pressure sensor in the prior art are solved, and the performance and reliability of the device are remarkably improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of flexible pressure sensors, and in particular relates to a pressure sensor based on an all-solid-state flexible organic electrochemical transistor and a preparation method thereof. Background Art

[0002] Flexible pressure sensors are key sensing devices in the fields of artificial intelligence, Internet of Things, robotics, etc., and are widely used in wearable devices, medical rehabilitation equipment, and soft robots due to their lightness, softness, deformability (including bending, compression, stretching, or twisting), and good human-computer interaction. However, most of the existing flexible pressure sensors use piezoresistive, capacitive, or piezoelectric sensing mechanisms. Although these sensors have good pressure sensitivity (0.7-100kPa -1 ) and simple device structures, but they are still limited by high voltage / power consumption, inherent charge leakage, or parasitic noise from the body and environment.

[0003] In the field of pressure sensors based on flexible organic transistors, they are mainly divided into organic field-effect transistors (OFETs) and organic electrochemical transistors. Among them, OFETs with microstructured gate dielectrics have demonstrated advanced pressure sensitivity, but their high driving voltage (30-200V) limits integration and portability. In contrast, OECTs are a class of devices that exhibit good electrical performance at low operating voltages (<1V). In OECTs, the organic semiconductor layer is in direct contact with the electrolyte as an ion source, and the reversible ion doping of the organic semiconductor layer is regulated by the applied gate voltage. Since the ion doping occurs over the entire volume of the organic semiconductor layer, OECTs have strong signal amplification capabilities and can achieve significant current modulation at low gate voltages. Therefore, OECTs have attracted increasing attention in applications such as neuromorphic computing, biosensing, cell monitoring, and neural interfaces.

[0004] However, conventional OECTs use liquid electrolytes, which limits their long-term operational stability, reproducibility, and integration capabilities, increasing the need for costly packaging. Furthermore, the use of liquid electrolytes makes OECTs difficult to apply to flexible pressure sensors. Therefore, the development of all-solid-state flexible OECTs is of great significance for improving sensor performance and expanding its application range. Summary of the Invention

[0005] To address the aforementioned problems in the prior art, the present invention provides a pressure sensor based on an all-solid-state flexible organic electrochemical transistor and a method for preparing the same. The technical problems to be solved by the present invention are achieved through the following technical solutions:

[0006] The embodiment of the present invention provides a pressure sensor based on an all-solid-state flexible organic electrochemical transistor, comprising: a PET substrate layer, a source electrode, a drain electrode, an organic semiconductor layer, a solid electrolyte layer, and a gate electrode, wherein:

[0007] The source electrode and the drain electrode are arranged on the PET substrate layer at intervals;

[0008] The organic semiconductor layer is located on the source electrode and the drain electrode, and is located on the PET substrate layer between the source electrode and the drain electrode;

[0009] The solid electrolyte layer is located on the organic semiconductor layer;

[0010] The gate electrode is located on the solid electrolyte layer, and has a pyramid array structure on a side facing the solid electrolyte layer, wherein a plurality of pyramids are distributed at intervals in the pyramid array structure.

[0011] In one embodiment of the present invention, the thickness of the PET substrate layer is 100-125 μm, and the PET substrate layer is obtained by oxygen plasma surface treatment.

[0012] In one embodiment of the present invention, the source electrode and the drain electrode are both made of AgNW material, both have a thickness of 200-300 nm, and the distance between the source electrode and the drain electrode is 20-200 μm.

[0013] In one embodiment of the present invention, the thickness of the organic semiconductor layer is 100-300 nm, and the organic semiconductor layer is formed by spraying a PEDOT:PSS solution doped with an ionic liquid, wherein the ionic liquid includes [EMIM][TFSI].

[0014] In one embodiment of the present invention, the solid electrolyte layer adopts a PEO-based solid electrolyte layer, and the materials of the PEO-based solid electrolyte layer include PEO, NaTFS and [EMIM][TFSI], and the mass ratio of PEO:NaTFSI:[EMIM][TFSI] is 1:0.75:0.44;

[0015] The thickness of the solid electrolyte layer is 150-200 μm.

[0016] In one embodiment of the present invention, the gate electrode is a PDMS composite electrode doped with CNTs, and the sheet resistance is 1-3 kΩ / sq;

[0017] The average height of the pyramids in the pyramid array structure is 180 μm, and the spacing between adjacent pyramids is 50-100 μm.

[0018] In one embodiment of the present invention, a conductive layer is further included, wherein the conductive layer is located between the solid electrolyte layer and the gate electrode;

[0019] The material of the conductive layer includes PEDOT:PSS.

[0020] Another embodiment of the present invention provides a method for preparing a pressure sensor of an all-solid-state flexible organic electrochemical transistor, comprising the steps of:

[0021] Under an inert atmosphere, NaTFSI and [EMIM][TFSI] ionic liquids were dissolved in anhydrous acetonitrile in a certain proportion, stirred, and PEO was added and continued to stir. The mixture was then allowed to stand and remove bubbles before being poured into a container and dried to obtain a solid electrolyte layer.

[0022] The PET substrate layer is sequentially cleaned and treated with oxygen plasma to obtain a pretreated PET substrate layer;

[0023] Spraying the diluted AgNW on the pretreated PET substrate layer to form a source electrode and a drain electrode spaced apart;

[0024] Spraying an ionic liquid-doped PEDOT:PSS solution on the source electrode, the drain electrode, and the PET substrate layer between the source electrode and the drain electrode, and annealing to form an organic semiconductor layer; wherein the ionic liquid comprises [EMIM][TFSI], and the mass fraction of the ionic liquid [EMIM][TFSI] in the total mass of the ionic liquid-doped PEDOT:PSS solution is 20-50 wt%;

[0025] transferring the solid electrolyte layer onto the organic semiconductor layer;

[0026] CNTs are sprayed on a silicon template with a pyramid array structure, followed by spin coating of PDMS, which is then cured and demolded to form a gate electrode with a pyramid array structure.

[0027] transferring the gate electrode onto the solid electrolyte layer so that the pyramid array structure faces the solid electrolyte layer;

[0028] Silver paste is used to connect the wires to the source electrode, the drain electrode and the gate electrode respectively and lead them out.

[0029] In one embodiment of the present invention, the spraying conditions of the source electrode and the drain electrode are: the distance between the spray gun and the substrate is 10-20 cm, the spraying pressure is 1-2 bar, the spraying temperature is 90° C., and the spraying time is 15-30 s;

[0030] The spraying conditions of the organic semiconductor layer are as follows: the distance between the spray gun and the substrate is 10-20 cm, the spraying pressure is 1-2 bar, the spraying temperature is 100° C., and the spraying time is 15-30 s;

[0031] The spraying conditions of the CNTs are as follows: the distance between the spray gun and the substrate is 10-20 cm, the spraying pressure is 1-2 bar, the spraying temperature is 90° C., and the spraying time is 60-90 s.

[0032] In one embodiment of the present invention, before transferring the gate electrode to the solid electrolyte layer, the method further comprises the following steps:

[0033] A PEDOT:PSS solution is sprayed on the surface of the solid electrolyte layer to form a conductive layer.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] 1. The pressure sensor of the present invention uses a solid electrolyte layer instead of the traditional liquid electrolyte. At the same time, a pyramid array structure is introduced on the side of the gate electrode facing the solid electrolyte layer, which significantly improves the sensitivity and response speed of the sensor to pressure. Thus, a pressure sensor with low-voltage drive, high sensitivity response and excellent stability is realized. This solves the problems of high operating voltage, easy leakage of liquid electrolyte and weak output signal in the flexible pressure sensor of the prior art, and significantly improves the performance and reliability of the device.

[0036] 2. The preparation method of the present invention adopts a full solution method to prepare the various components of the pressure sensor, and combines it with spray patterning technology. It not only has a simple process and low cost, but also can achieve large area, flexibility and transparency; this preparation method avoids complex processes such as traditional vacuum evaporation, reduces equipment investment and maintenance costs; in addition, the full solution method combined with spraying technology can achieve high-precision patterning, improve device performance and production efficiency, and is particularly suitable for large-scale industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 A schematic structural diagram of a pressure sensor based on an all-solid-state flexible organic electrochemical transistor provided by an embodiment of the present invention;

[0038] Figure 2 A schematic structural diagram of another pressure sensor based on an all-solid-state flexible organic electrochemical transistor provided by an embodiment of the present invention;

[0039] Figure 3 A schematic diagram of a method for preparing a pressure sensor of an all-solid-state flexible organic electrochemical transistor provided by an embodiment of the present invention;

[0040] Figure 4A schematic structural diagram of an all-solid-state flexible organic electrochemical transistor provided by the present invention;

[0041] Figure 5 1 is the transfer characteristic curve of the all-solid-state flexible organic electrochemical transistor with different solid electrolyte components in the embodiment of the present invention;

[0042] Figure 6 A schematic structural diagram of another all-solid-state flexible organic electrochemical transistor provided by the present invention;

[0043] Figure 7 2 are the transfer characteristic curve and output characteristic curve of the all-solid-state flexible organic electrochemical transistor in an embodiment of the present invention;

[0044] Figure 8 These are the transfer characteristic curves and output characteristic curves of the pressure sensor based on the all-solid-state flexible organic electrochemical transistor (OECT) under different pressures in an embodiment of the present invention. DETAILED DESCRIPTION

[0045] The present invention will be further described in detail below with reference to specific examples, but the embodiments of the present invention are not limited thereto.

[0046] See Figure 1 , Figure 1 A schematic diagram of the structure of a pressure sensor based on an all-solid-state flexible organic electrochemical transistor provided by an embodiment of the present invention. The pressure sensor adopts an all-solid-state flexible organic electrochemical transistor structure, comprising: a PET substrate layer 1, a source electrode 2, a drain electrode 3, an organic semiconductor layer 4, a solid electrolyte layer 5, and a gate electrode 6. The source electrode 2 and the drain electrode 3 are spaced apart on the PET substrate layer 1; the organic semiconductor layer 4 is located on the source electrode 2 and the drain electrode 3, and is located on the PET substrate layer 1 between the source electrode 2 and the drain electrode 3; the solid electrolyte layer 5 is located on the organic semiconductor layer 4; and the gate electrode 6 is located on the solid electrolyte layer 5 and has a pyramid array structure on the side facing the solid electrolyte layer 5, with several pyramids spaced apart in the pyramid array structure.

[0047] Specifically, the pressure sensor functional layers described above are all prepared using a full solution process. The PET substrate layer 1 is a flexible, transparent substrate. The source and drain electrodes 2 and 3 are made of highly conductive materials, offering excellent flexibility and flex resistance. The organic semiconductor layer 4 is composed of a material that combines high conductivity with flexibility. The solid electrolyte layer 5 utilizes a PEO-based solid electrolyte. The gate electrode 6 is a highly elastic composite electrode with a pyramidal array structure designed on its surface to enhance pressure sensitivity.

[0048] Specifically, the thickness of the PET substrate layer 1 is 100-125 μm. The PET substrate layer 1 is subjected to oxygen plasma surface treatment to enhance adhesion with the source and drain electrodes and the organic semiconductor layer 4 .

[0049] Specifically, the source electrode 2 and the drain electrode 3 are both made of silver nanowire (AgNW) material, and both have a thickness of 200-300 nm. The distance between the source electrode 2 and the drain electrode 3 is 20-200 μm.

[0050] Specifically, the organic semiconductor layer 4 is formed by spraying a poly (3,4-ethylenedioxythiophene): polystyrene sulfonic acid) (PEDOT:PSS) solution doped with an ionic liquid, wherein the ionic liquid includes 1-ethyl-3-methylimidazolium bis (trifluoromethanesulfonyl imide) ([EMIM][TFSI]), wherein the mass ratio of PEDOT:PSS to [EMIM][TFSI] is 1:1.

[0051] Specifically, solid electrolyte layer 5 utilizes a polyethylene oxide (PEO)-based solid electrolyte layer, prepared by solution casting. The PEO-based solid electrolyte layer comprises PEO, sodium bis(trifluoromethylsulfonyl)imide (NaTFS), and [EMIM][TFSI], with a mass ratio of PEO:NaTFSI:[EMIM][TFSI] of 1:0.75:0.44. Solid electrolyte layer 5 has a thickness of 150-200 μm.

[0052] Specifically, gate electrode 6 is a carbon nanotube (CNT)-doped polydimethylsiloxane (PDMS) composite electrode with a sheet resistance of 1-3 kΩ / sq and an overall thickness of 300-700 μm, for example, 500 μm. In the pyramid array structure of gate electrode 6, the average height of the pyramids is 180 μm, and the spacing between adjacent pyramids is 50-100 μm.

[0053] See Figure 2 , Figure 2 A schematic structural diagram of another pressure sensor based on an all-solid-state flexible organic electrochemical transistor provided in an embodiment of the present invention.

[0054] The pressure sensor includes a PET substrate layer 1, a source electrode 2, a drain electrode 3, an organic semiconductor layer 4, a solid electrolyte layer 5, a gate electrode 6, and a conductive layer 7. The conductive layer 7 is located between the solid electrolyte layer 5 and the gate electrode 6; the conductive layer 7 is made of PEDOT:PSS.

[0055] In this embodiment, a PEDOT:PSS conductive layer is provided between the solid electrolyte layer 5 and the gate electrode 6 , which can reduce the electrochemical impedance and potential drop between the gate and electrolyte interface and improve the gate control capability of the device.

[0056] This embodiment designs a polydimethylsiloxane (PDMS) composite electrode doped with carbon nanotubes (CNTs) to have a pyramid array structure, which significantly improves the sensitivity and response speed of the sensor to pressure. This structural design not only enhances the mechanical properties of the electrode, but also optimizes the electrical properties. Under pressure, the tip of the pyramid structure will produce local stress concentration, resulting in a rapid change in the contact area, thereby rapidly changing the resistance between the electrode and the electrolyte. This process effectively shortens the response time of the sensor, achieves a fast electrical response, enables it to work efficiently at low voltage, and significantly improves the overall performance of the sensor.

[0057] This embodiment uses a PEO-based solid electrolyte instead of a traditional liquid electrolyte, addressing the issues of leaks and poor stability of liquid electrolytes. PEO-based electrolytes offer excellent mechanical properties and flexibility, significantly improving the long-term operational capability and integration of devices. Furthermore, PEO-based electrolytes offer the advantages of low cost and ease of large-scale production.

[0058] The sensor of this embodiment uses an organic electrochemical transistor (OECT) to replace the traditional pressure sensor. The operating voltage is lower than 1V, which significantly reduces power consumption, has a switching ratio of up to 1000, and a transconductance of 4.73mS, showing high sensitivity, low power consumption and excellent stability. OECT exhibits superior performance due to its low operating voltage, high sensitivity and strong signal amplification capability. In addition, OECT also has fast response, high signal-to-noise ratio and good biocompatibility, which makes it have broad application prospects in the field of biomedical sensors. These characteristics make OECT a key technology for the development of high-performance bioelectronic devices. It is suitable for wearable devices, medical monitoring and soft robots and other fields, showing broad application prospects.

[0059] It should be noted that Figure 1 and Figure 2 The illustrated embodiment only schematically shows a positional relationship diagram of the PET substrate layer 1, source electrode 2, drain electrode 3, organic semiconductor layer 4, solid electrolyte layer 5, gate electrode 6 and conductive layer 7, and does not represent the actual size.

[0060] See Figure 3 , Figure 3 A schematic diagram of a method for preparing a pressure sensor of an all-solid-state flexible organic electrochemical transistor provided by an embodiment of the present invention. The method for preparing a pressure sensor of an all-solid-state flexible organic electrochemical transistor comprises the following steps:

[0061] S101. Using a solution casting method, under an inert atmosphere, NaTFSI and [EMIM][TFSI] ionic liquids are dissolved in anhydrous acetonitrile in a certain proportion, stirred, and PEO is added and continued to stir. The mixture is then allowed to stand and bubbles are removed before being poured into a container and dried to obtain a solid electrolyte layer 5.

[0062] Specifically, in an argon-filled glove box, 0.75 g of NaTFSI and [EMIM][TFSI] were each dissolved in anhydrous acetonitrile. After stirring for 1-2 hours, 1 g of PEO was added and stirring continued at a low speed for 12-24 hours. The mixture was allowed to stand for a period of time to remove some bubbles. After vacuuming to remove any remaining bubbles, the mixture was poured into a Petri dish with a PDMS substrate at the bottom and dried at room temperature for 48-72 hours to obtain a PEO-based solid electrolyte layer 5. The mass of [EMIM][TFSI] accounted for 20% of the total mass of NaTFSI, [EMIM][TFSI], and PEO, i.e., the mass ratio of PEO:NaTFSI:[EMIM][TFSI] was 1:0.75:0.44.

[0063] Specifically, the thickness of the prepared solid electrolyte layer 5 is 150-200 μm.

[0064] S102 , sequentially cleaning and oxygen plasma treating the PET substrate layer 1 to obtain a pretreated PET substrate layer 1 .

[0065] Specifically, the PET substrate layer 1 is cleaned in an ultrasonic bath using deionized water, acetone, and ethanol, followed by oxygen plasma treatment at 10-50W for 5-10 minutes to enhance adhesion to the source electrode 2, drain electrode 3, and organic semiconductor layer 4. The thickness of the PET substrate layer 1 is 100-125 μm.

[0066] S103 , spraying the diluted AgNW onto the pre-treated PET substrate layer 1 to form a source electrode 2 and a drain electrode 3 that are spaced apart.

[0067] Specifically, first, the AgNW dispersion is diluted with ethanol, and the volume ratio of the AgNW dispersion to ethanol is 1:4, wherein the AgNW dispersion refers to a solution of AgNWs dispersed in ethanol with an original concentration of 1wt%. Then, a spray gun is used to spray the patterned source electrode 2 and drain electrode 3 on the treated PET substrate layer 1, and the spray gun parameters are adjusted to ensure the uniformity and consistency of the electrodes. Among them, the spray gun parameters during spraying are set according to the following conditions: the distance between the spray gun and the substrate is 10-20cm, the spraying pressure is 1-2bar, the spraying temperature is 90°C, and the spraying time is 15-30s. The thickness of the source electrode 2 and the drain electrode 3 is 200-300nm, and the spacing between the source electrode 2 and the drain electrode 3 is 20-200μm.

[0068] S104 , spraying an ionic liquid-doped PEDOT:PSS solution on the source electrode 2 , the drain electrode 3 , and the PET substrate layer 1 between the source electrode 2 and the drain electrode 3 , and performing annealing to form an organic semiconductor layer 4 .

[0069] Specifically, an ionic liquid-doped PEDOT:PSS solution is sprayed onto the source electrode 2, the drain electrode 3, and the PET substrate layer 1 between the source and drain electrodes 2 and 3 to form an organic semiconductor layer 4. The ionic liquid is [EMIM][TFSI], and the mass fraction of [EMIM][TFSI] in the total mass of the ionic liquid-doped PEDOT:PSS solution is 20-50 wt%. During spraying, the distance between the spray gun and the substrate is 10-20 cm, the spraying pressure is 1-2 bar, the spraying temperature is 100°C, and the spraying time is 15-30 seconds. The organic semiconductor layer 4 has a thickness of 100-300 nm and is annealed at 100-150°C for 20-60 minutes to optimize its electrical properties.

[0070] S105 , transferring the solid electrolyte layer 5 onto the organic semiconductor layer 4 .

[0071] Specifically, the solid electrolyte layer 5 prepared in step S101 is cut into a preset size, and then the solid electrolyte layer 5 is adhered to the organic semiconductor layer 4, and the PDMS substrate is peeled off.

[0072] S106, spraying CNTs on the silicon template with the pyramid array structure and then spin-coating PDMS, curing and demolding to form a gate electrode 6 with a pyramid array structure; and transferring the gate electrode 6 to the solid electrolyte layer 5 so that the pyramid array structure faces the solid electrolyte layer 5.

[0073] Specifically, after spraying CNTs on a silicon template with a pyramid array structure, PDMS is spin-coated, and after curing and demolding, a microstructured gate electrode 6 is formed. When spraying CNTs, the distance between the spray gun and the substrate is 10-20 cm, the spraying pressure is 1-2 bar, the spraying temperature is 90°C, and the spraying time is 60-90 s. The average height of the pyramid array structure of the gate electrode 6 is 180 μm, the spacing between adjacent pyramids is 50-100 μm, and the square resistance of the gate electrode 6 is 1-3 kΩ / sq. The microstructured gate electrode 6 is transferred to the top of the PEO-based solid electrolyte layer 5 so that the microstructure faces the PEO-based solid electrolyte layer 5.

[0074] S107, using silver paste to connect the wires to the source electrode 2, the drain electrode 3 and the gate electrode 6 respectively and lead them out to complete the assembly of the device, and prepare the following Figure 1 The device shown.

[0075] In a specific embodiment, the steps between step S105 and step S106 may further include: spraying a PEDOT:PSS solution on the surface of the solid electrolyte layer 5 to form a conductive layer 7, and preparing the Figure 2 The device shown.

[0076] The preparation method of this embodiment adopts a full solution method to prepare the various components of the pressure sensor, and combines it with spray patterning technology. It not only has a simple process and low cost, but also can achieve large area, flexibility and transparency. This preparation method avoids complex processes such as traditional vacuum evaporation, reducing equipment investment and maintenance costs. In addition, the full solution method combined with spray technology can achieve high-precision patterning, improve device performance and production efficiency, and is particularly suitable for large-scale industrial production.

[0077] Therefore, this embodiment proposes a pressure sensor based on an all-solid-state flexible organic electrochemical transistor and a preparation method thereof. The efficient preparation of the device is achieved through the full solution method and spraying technology. By adopting spraying technology to prepare each functional layer, using a solid electrolyte layer to replace the traditional liquid electrolyte, and introducing a pyramid array structure gate electrode, a pressure sensor with low voltage drive, high sensitivity response and excellent stability is realized, which solves the problems of high operating voltage, easy leakage of liquid electrolyte and weak output signal of flexible pressure sensors in the prior art, and significantly improves the performance and reliability of the device.

[0078] For the convenience of understanding the present invention, the present invention is given below with examples. It should be understood by those skilled in the art that the examples are only for the purpose of helping to understand the present invention and should not be regarded as specific limitations of the present invention.

[0079] Example 1

[0080] In this embodiment, the preparation of an all-solid-state flexible organic electrochemical transistor is achieved through the following steps.

[0081] S101. Preparation of solid electrolyte

[0082] In an argon-filled glove box, 0.75 g of NaTFSI was dissolved in anhydrous acetonitrile and stirred for 1 hour. Then, 1 g of PEO was added and stirred at a low speed for 8 hours. The mixture was allowed to stand and vacuumed to remove bubbles. The mixture was then poured into a Petri dish with a PDMS substrate and dried at room temperature for 48 hours to obtain a PEO-based solid electrolyte layer 5. The thickness of the solid electrolyte layer 5 was 150-200 μm.

[0083] S102, pretreatment of PET substrate layer

[0084] The PET substrate layer 1 was cleaned in an ultrasonic bath using deionized water, acetone, and ethanol, followed by oxygen plasma treatment at 40 W for 10 minutes to enhance adhesion to the source electrode 2, drain electrode 3, and organic semiconductor layer 4. The thickness of the PET substrate layer 1 was 100 μm.

[0085] S103. Preparation of source and drain electrodes

[0086] After diluting the AgNW dispersion with ethanol (the volume ratio of AgNW dispersion to ethanol was 1:4), patterned source and drain electrodes 2 and 3 were sprayed onto the treated PET substrate layer 1 using a spray gun. The spray gun was held at a distance of 12 cm from the substrate, with a pressure of 1.6 bar, a temperature of 90°C, and a spraying time of 15 seconds. The thickness of the source and drain electrodes was 300 nm, and the spacing between them was 200 μm.

[0087] S104. Preparation of organic semiconductor layer

[0088] An ionic liquid-doped PEDOT:PSS solution (the mass fraction of the ionic liquid [EMIM][TFSI] in the doping liquid was 50 wt%) was sprayed onto the source electrode 2 and drain electrode 3 to form the organic semiconductor layer 4. During spraying, the spray gun was held at a distance of 15 cm from the substrate, the spray pressure was 1 bar, the spray temperature was 100°C, and the spraying time was 15 seconds. The organic semiconductor layer had a thickness of 200 nm and was annealed at 120°C for 30 minutes to optimize its electrical properties.

[0089] S105. Transfer of solid electrolyte layer

[0090] The prepared PEO-based solid electrolyte layer 5 is transferred onto the organic semiconductor layer 4 .

[0091] S106. Preparation of gate electrode

[0092] After diluting the CNTs, a patterned gate electrode 6 was sprayed onto the treated PET substrate layer 1 using a spray gun. The CNTs were sprayed at a distance of 12 cm from the substrate, a pressure of 1.6 bar, a temperature of 90°C, a spray time of 90 seconds, and a sheet resistance of 1-3 kΩ / sq. The gate electrode was then transferred onto the PEO-based solid electrolyte layer 5.

[0093] S107, Wire connection and device assembly

[0094] Silver paste is used to connect the wires to the source electrode 2 , the drain electrode 3 , and the gate electrode 6 respectively and lead them out to complete the assembly of the device.

[0095] Example 2

[0096] In this embodiment, the preparation of an all-solid-state flexible organic electrochemical transistor is achieved through the following steps.

[0097] S101. Preparation of solid electrolyte

[0098] In an argon-filled glove box, 0.75 g of NaTFSI and 20 wt% of the total mass of [EMIM][TFSI], representing [EMIM][TFSI], and PEO, were dissolved in anhydrous acetonitrile. After stirring for 1 hour, 1 g of PEO was added and stirring continued at low speed for 8 hours. The mixture was allowed to stand and vacuumed to remove bubbles before being poured into a Petri dish with a PDMS substrate. The mixture was dried at room temperature for 48 hours to obtain a PEO-based solid electrolyte layer 5. The thickness of the solid electrolyte layer was 150-200 μm.

[0099] S102, pretreatment of PET substrate layer

[0100] The PET substrate layer 1 was cleaned in an ultrasonic bath using deionized water, acetone, and ethanol, followed by oxygen plasma treatment at 40 W for 10 min to enhance adhesion to the source electrode 2, drain electrode 3, and organic semiconductor layer 4. The thickness of the PET substrate layer was 100 μm.

[0101] S103. Preparation of source and drain electrodes

[0102] After diluting the AgNW dispersion with ethanol (the volume ratio of AgNW dispersion to ethanol was 1:4), patterned source and drain electrodes 2 and 3 were sprayed onto the treated PET substrate layer 1 using a spray gun. The spray gun was held at a distance of 12 cm from the substrate, with a pressure of 1.6 bar, a temperature of 90°C, and a spraying time of 15 seconds. The source and drain electrodes were 300 nm thick, with a 200 μm spacing.

[0103] S104. Preparation of organic semiconductor layer

[0104] An ionic liquid-doped PEDOT:PSS solution (the mass fraction of the ionic liquid [EMIM][TFSI] in the doping liquid was 50 wt%) was sprayed onto the source electrode 2 and drain electrode 3 to form the organic semiconductor layer 4. During spraying, the spray gun was held at a distance of 15 cm from the substrate, the spray pressure was 1 bar, the spray temperature was 100°C, and the spraying time was 15 seconds. The organic semiconductor layer had a thickness of 200 nm and was annealed at 120°C for 30 minutes to optimize its electrical properties.

[0105] S105. Transfer of solid electrolyte layer

[0106] The prepared PEO-based solid electrolyte layer 5 is transferred onto the organic semiconductor layer 4 .

[0107] S106. Preparation of gate electrode

[0108] After diluting the CNTs, a patterned gate electrode 6 was sprayed onto the treated PET substrate layer 1 using a spray gun. The CNTs were sprayed at a distance of 12 cm from the substrate, a pressure of 1.6 bar, a temperature of 90°C, a spray time of 90 seconds, and a sheet resistance of 1-3 kΩ / sq. The gate electrode was then transferred onto the PEO-based solid electrolyte layer 5.

[0109] S107, Wire connection and device assembly

[0110] Silver paste is used to connect the wires to the source electrode 2 , the drain electrode 3 , and the gate electrode 6 respectively and lead them out to complete the assembly of the device.

[0111] Example 3

[0112] In this embodiment, the preparation of the all-solid-state flexible organic electrochemical transistor is achieved through the following steps.

[0113] S101. Preparation of solid electrolyte

[0114] In an argon-filled glove box, 0.25 g of NaTFSI and 20 wt% of the total mass of [EMIM][TFSI], representing 20 wt% of the total mass of NaTFSI, [EMIM][TFSI], and PEO, were dissolved in anhydrous acetonitrile. After stirring for 1 hour, 1 g of PEO was added and stirring continued at low speed for 8 hours. The mixture was allowed to stand and vacuumed to remove bubbles before being poured into a Petri dish with a PDMS substrate. The mixture was dried at room temperature for 48 hours to obtain a PEO-based solid electrolyte layer 5. The thickness of the solid electrolyte layer was 150-200 μm.

[0115] S102, pretreatment of PET substrate layer

[0116] The PET substrate layer 1 was cleaned in an ultrasonic bath using deionized water, acetone, and ethanol, followed by oxygen plasma treatment at 40 W for 10 min to enhance adhesion to the source electrode 2, drain electrode 3, and organic semiconductor layer 4. The thickness of the PET substrate layer was 100 μm.

[0117] S103. Preparation of source and drain electrodes

[0118] After diluting the AgNW dispersion with ethanol (the volume ratio of AgNW dispersion to ethanol was 1:4), patterned source and drain electrodes 2 and 3 were sprayed onto the treated PET substrate layer 1 using a spray gun. The spray gun was held at a distance of 12 cm from the substrate, with a pressure of 1.6 bar, a temperature of 90°C, and a spraying time of 15 seconds. The source and drain electrodes were 300 nm thick, with a 200 μm spacing.

[0119] S104. Preparation of organic semiconductor layer

[0120] An ionic liquid-doped PEDOT:PSS solution (the mass fraction of the ionic liquid [EMIM][TFSI] in the doping liquid was 50 wt%) was sprayed onto the source electrode 2 and drain electrode 3 to form the organic semiconductor layer 4. During spraying, the spray gun was held at a distance of 15 cm from the substrate, the spray pressure was 1 bar, the spray temperature was 100°C, and the spraying time was 15 seconds. The organic semiconductor layer had a thickness of 200 nm and was annealed at 120°C for 30 minutes to optimize its electrical properties.

[0121] S105. Transfer of solid electrolyte layer

[0122] The prepared PEO-based solid electrolyte layer 5 is transferred onto the organic semiconductor layer 4 .

[0123] S106. Preparation of gate electrode

[0124] After diluting the CNTs, a patterned gate electrode 6 was sprayed onto the treated PET substrate layer 1 using a spray gun. The CNTs were sprayed at a distance of 12 cm from the substrate, a pressure of 1.6 bar, a temperature of 90°C, a spray time of 90 seconds, and a sheet resistance of 1-3 kΩ / sq. The electrode was then transferred onto the PEO-based solid electrolyte layer 5.

[0125] S107, Wire connection and device assembly

[0126] Silver paste is used to connect the wires to the source electrode 2 , the drain electrode 3 , and the gate electrode 6 respectively and lead them out to complete the assembly of the device.

[0127] The devices prepared in Example 1, Example 2 and Example 3 are as follows Figure 4 As shown, Figure 4 This is a schematic structural diagram of an all-solid-state flexible organic electrochemical transistor provided by the present invention.

[0128] See Figure 5 , Figure 5 The transfer characteristic curves of all-solid-state flexible organic electrochemical transistors with different solid electrolyte components in the embodiments of the present invention. In order to explore the effects of solid electrolytes with different components on the performance of organic electrochemical transistors, the present invention designed three embodiments. In Example 1, the mass ratio of PEO to NaTFSI is 1:0.75, and [EMIM][TFSI] is not added; in Example 2, the mass ratio of PEO to NaTFSI is also 1:0.75, but the mass fraction of [EMIM][TFSI] is 20wt%; in Example 3, the mass ratio of PEO to NaTFSI is adjusted to 1:0.2, and the mass fraction of [EMIM][TFSI] is maintained at 20wt%. The transfer curves of these components were experimentally studied, and the experimental results are as follows. Figure 5 shown.

[0129] A comparison of Examples 1 and 2 reveals that, while the mass ratio of PEO to NaTFSI remains constant, the addition of [EMIM][TFSI] shifts the transfer curve toward lower gate voltages. This phenomenon suggests that the addition of [EMIM][TFSI] further increases the ionic conductivity of the electrolyte, generating more cations and enhancing the device's electrical performance.

[0130] Further comparison of Examples 2 and 3 reveals that, when the mass fraction of [EMIM][TFSI] is fixed at 20 wt%, the off-state of the transfer curve shifts toward lower gate voltages as the NaTFSI content increases. This indicates that increasing the NaTFSI content generates more cations in the electrolyte. At the same gate voltage, these cations can more efficiently enter the PEDOT:PSS film, making it easier to control the output current and improving signal amplification.

[0131] Example 4

[0132] In this embodiment, the preparation of an all-solid-state flexible organic electrochemical transistor is achieved through the following steps.

[0133] S101. Preparation of solid electrolyte

[0134] In an argon-filled glove box, 0.75 g of NaTFSI and 20 wt% of the total mass of [EMIM][TFSI], representing [EMIM][TFSI], and PEO, were dissolved in anhydrous acetonitrile. After stirring for 1 hour, 1 g of PEO was added and stirring continued at low speed for 8 hours. The mixture was allowed to stand and vacuumed to remove bubbles before being poured into a Petri dish with a PDMS substrate. The mixture was dried at room temperature for 48 hours to obtain a PEO-based solid electrolyte layer 5. The thickness of the solid electrolyte layer was 150-200 μm.

[0135] S102, pretreatment of PET substrate layer

[0136] The PET substrate layer 1 was cleaned in an ultrasonic bath using deionized water, acetone, and ethanol, followed by oxygen plasma treatment at 40 W for 10 min to enhance adhesion to the source electrode 2, drain electrode 3, and organic semiconductor layer 4. The thickness of the PET substrate layer was 100 μm.

[0137] S103. Preparation of source and drain electrodes

[0138] After diluting the AgNW dispersion with ethanol (the volume ratio of AgNW dispersion to ethanol was 1:4), patterned source and drain electrodes 2 and 3 were sprayed onto the treated PET substrate layer 1 using a spray gun. The spray gun was held at a distance of 12 cm from the substrate, with a pressure of 1.6 bar, a temperature of 90°C, and a spraying time of 15 seconds. The source and drain electrodes were 300 nm thick, with a 200 μm spacing.

[0139] S104. Preparation of organic semiconductor layer

[0140] An ionic liquid-doped PEDOT:PSS solution (the mass fraction of the ionic liquid [EMIM][TFSI] in the doping liquid was 50 wt%) was sprayed onto the source electrode 2 and drain electrode 3 to form the organic semiconductor layer 4. During spraying, the spray gun was held at a distance of 15 cm from the substrate, the spray pressure was 1 bar, the spray temperature was 100°C, and the spraying time was 15 seconds. The organic semiconductor layer had a thickness of 200 nm and was annealed at 120°C for 30 minutes to optimize its electrical properties.

[0141] S105. Transfer of solid electrolyte layer

[0142] The prepared PEO-based solid electrolyte layer 5 is transferred onto the organic semiconductor layer 4 .

[0143] Subsequently, a PEDOT:PSS solution was sprayed on the solid electrolyte surface near the gate to form a conductive layer 7. During spraying, the distance between the spray gun and the substrate was 15 cm, the spraying pressure was 1.6 bar, the spraying temperature was 100°C, and the spraying time was 8 s.

[0144] S106. Preparation of gate electrode

[0145] After diluting the CNTs, a patterned gate electrode 6 was sprayed onto the treated PET substrate layer 1 using a spray gun. The CNTs were sprayed at a distance of 12 cm from the substrate, a pressure of 1.6 bar, a temperature of 90°C, a spray time of 90 seconds, and a sheet resistance of 1-3 kΩ / sq. The gate electrode was then transferred onto the PEO-based solid electrolyte layer 5.

[0146] S107, Wire connection and device assembly

[0147] Silver paste is used to connect the wires to the source electrode 2 , the drain electrode 3 , and the gate electrode 6 respectively and lead them out to complete the assembly of the device.

[0148] The device prepared in Example 4 is as follows Figure 6 As shown, Figure 6 A schematic structural diagram of another all-solid-state flexible organic electrochemical transistor provided by the present invention.

[0149] See Figure 5 and Figure 7 , Figure 7 : are the transfer characteristic curve and output characteristic curve of the all-solid-state flexible organic electrochemical transistor in the embodiment of the present invention, Figure 7 (a) is the transfer characteristic curve, and (b) is the output characteristic curve. In order to further improve the gate control capability of the organic electrochemical transistor (OECT), a layer of PEDOT:PSS is added between the gate and the electrolyte. This design aims to reduce the electrochemical impedance and potential drop between the gate and the electrolyte interface. By comparing two devices with different structures: Example 2 (without PEDOT:PSS layer) and Example 5 (with PEDOT:PSS layer), the changes in the transfer curve are shown in the figure. Figure 5 and Figure 7 The results show that after adding the PEDOT:PSS layer, the transfer curve shifts significantly toward lower gate voltages, indicating that the gate control capability of the device has been significantly improved, with an on / off ratio as high as 1000 and a transconductance of 4.73mS.

[0150] Example 5

[0151] In this embodiment, the preparation of a pressure sensor of an all-solid-state flexible organic electrochemical transistor is achieved through the following steps.

[0152] S101. Preparation of solid electrolyte

[0153] In an argon-filled glove box, 0.75 g of NaTFSI and 20 wt% of the total mass of [EMIM][TFSI], representing [EMIM][TFSI], and PEO, were dissolved in anhydrous acetonitrile. After stirring for 1 hour, 1 g of PEO was added and stirring continued at low speed for 8 hours. The mixture was allowed to stand and vacuumed to remove bubbles before being poured into a Petri dish with a PDMS substrate. The mixture was dried at room temperature for 48 hours to obtain a PEO-based solid electrolyte layer 5. The thickness of the solid electrolyte layer was 150-200 μm.

[0154] S102, pretreatment of PET substrate layer

[0155] The PET substrate layer 1 was cleaned in an ultrasonic bath using deionized water, acetone, and ethanol, followed by oxygen plasma treatment at 40 W for 10 min to enhance adhesion to the source electrode 2, drain electrode 3, and organic semiconductor layer 4. The thickness of the PET substrate layer was 100 μm.

[0156] S103. Preparation of source and drain electrodes

[0157] After diluting the AgNW dispersion with ethanol (the volume ratio of AgNW dispersion to ethanol was 1:4), patterned source and drain electrodes 2 and 3 were sprayed onto the treated PET substrate layer 1 using a spray gun. The spray gun was held at a distance of 12 cm from the substrate, with a pressure of 1.6 bar, a temperature of 90°C, and a spraying time of 15 seconds. The source and drain electrodes were 300 nm thick, with a 200 μm spacing.

[0158] S104. Preparation of organic semiconductor layer

[0159] An ionic liquid-doped PEDOT:PSS solution (the mass fraction of the ionic liquid [EMIM][TFSI] in the doping liquid was 50 wt%) was sprayed onto the source electrode 2 and drain electrode 3 to form the organic semiconductor layer 4. During spraying, the spray gun was held at a distance of 15 cm from the substrate, the spray pressure was 1 bar, the spray temperature was 100°C, and the spraying time was 15 seconds. The organic semiconductor layer had a thickness of 200 nm and was annealed at 120°C for 30 minutes to optimize its electrical properties.

[0160] S105. Transfer of solid electrolyte layer

[0161] The prepared PEO-based solid electrolyte layer 5 is transferred onto the organic semiconductor layer 4 .

[0162] Then, a PEDOT:PSS solution was sprayed on the solid electrolyte surface near the gate to form a conductive layer 7. During spraying, the distance between the spray gun and the substrate was 15 cm, the spraying pressure was 1.6 bar, the spraying temperature was 100°C, and the spraying time was 8 s.

[0163] S106. Preparation of gate electrode

[0164] After spraying CNTs onto a silicon template with a pyramid array structure, PDMS was spin-coated, cured, and then released from the mold to form a microstructured gate electrode 6. During CNT spraying, the spray gun was positioned at a distance of 12 cm from the substrate, with a spray pressure of 1.6 bar, a spray temperature of 90°C, and a spraying time of 90 seconds. The average height of the pyramid array structure of the gate electrode was 180 μm, with a spacing of 85 μm between adjacent pyramids and a sheet resistance of 1-3 kΩ / sq. The microstructured gate electrode was then transferred onto the PEO-based solid electrolyte layer 5.

[0165] S107, Wire connection and device assembly

[0166] Silver paste is used to connect the wires to the source electrode 2 , the drain electrode 3 , and the gate electrode 6 respectively and lead them out to complete the assembly of the device.

[0167] The device structure prepared in Example 5 is as follows Figure 2 shown.

[0168] See Figure 8 , Figure 8 The transfer characteristic curves and output characteristic curves of the pressure sensor based on the all-solid-state flexible organic electrochemical transistor (OECT) in Example 5 of the present invention under different pressures are shown, wherein: Figure 8 (a) is the transfer characteristic curve, and (b) is the output characteristic curve. When there is no external pressure, the OECT is in a modulation state by applying source-drain voltage and gate voltage. When a uniform pressure perpendicular to the plane direction is applied to the transistor, the micro-pyramid structure on the gate will deform, thereby changing the contact area and distance between the gate and the PEDOT:PSS layer, causing the resistance between the two to change, and ultimately affecting the modulation effect. Therefore, the external pressure is output in the form of source-drain current. Figure 8 As shown in the figure, as the pressure increases, the deformation of the gate becomes more significant and the output source-drain current gradually decreases. This shows that the pressure sensor can sensitively respond to pressure changes through the micro-pyramid structure of the gate and detect pressure signals in the form of current changes.

[0169] In summary, the embodiments of the present invention achieve a significant improvement in the performance of all-solid-state flexible OECTs by optimizing the components and structural design of the solid-state electrolyte. Specifically, by adjusting the ratio of PEO, NaTFSI and [EMIM][TFSI], it is found that the addition of [EMIM][TFSI] can improve the ionic conductivity of the electrolyte, thereby enhancing the electrical performance of the device. Furthermore, adding a PEDOT:PSS layer between the gate and the electrolyte effectively reduces the interfacial electrochemical impedance and significantly improves the gate control capability. In addition, the gate design with a micro-pyramid structure enables the pressure sensor to respond sensitively to pressure changes and detect pressure signals in the form of current changes.

[0170] In the description of this specification, the reference terms "one embodiment," "some embodiments," "example," "specific example," or "some examples" mean that the specific features or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features or characteristics described can be combined in any suitable manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification.

[0171] The above is a further detailed description of the present invention in conjunction with specific preferred embodiments, and the specific implementation of the present invention should not be considered to be limited to these descriptions. For those skilled in the art of the present invention, without departing from the concept of the present invention, several simple deductions or substitutions can be made, which should be considered to fall within the scope of protection of the present invention.

Claims

1. A pressure sensor based on an all-solid-state flexible organic electrochemical transistor, characterized in that: include: PET substrate layer (1), source electrode (2), drain electrode (3), organic semiconductor layer (4), solid electrolyte layer (5) and gate electrode (6), wherein, The source electrode (2) and the drain electrode (3) are arranged on the PET substrate layer (1) at intervals; The organic semiconductor layer (4) is located on the source electrode (2) and the drain electrode (3), and is located on the PET substrate layer (1) between the source electrode (2) and the drain electrode (3); The solid electrolyte layer (5) is located on the organic semiconductor layer (4); The gate electrode (6) is located on the solid electrolyte layer (5), and has a pyramid array structure on a side facing the solid electrolyte layer (5), wherein a plurality of pyramids are distributed at intervals in the pyramid array structure.

2. The all-solid-state flexible organic electrochemical transistor pressure sensor according to claim 1, characterized in that: The thickness of the PET substrate layer (1) is 100-125 μm, and the PET substrate layer (1) is obtained by oxygen plasma surface treatment.

3. The all-solid-state flexible organic electrochemical transistor pressure sensor according to claim 1, characterized in that: The source electrode (2) and the drain electrode (3) are both made of AgNW material, both have a thickness of 200-300 nm, and the distance between the source electrode (2) and the drain electrode (3) is 20-200 μm.

4. The all-solid-state flexible organic electrochemical transistor pressure sensor according to claim 1, characterized in that: The thickness of the organic semiconductor layer (4) is 100-300 nm. The organic semiconductor layer (4) is formed by spraying a PEDOT:PSS solution doped with an ionic liquid, wherein the ionic liquid comprises [EMIM][TFSI].

5. The all-solid-state flexible organic electrochemical transistor pressure sensor according to claim 1, characterized in that: The solid electrolyte layer (5) adopts a PEO-based solid electrolyte layer, wherein the materials of the PEO-based solid electrolyte layer include PEO, NaTFS and [EMIM][TFSI], and the mass ratio of PEO:NaTFSI:[EMIM][TFSI] is 1:0.75:0.44; The thickness of the solid electrolyte layer (5) is 150-200 μm.

6. The all-solid-state flexible organic electrochemical transistor pressure sensor according to claim 1, characterized in that: The gate electrode (6) is a PDMS composite electrode doped with CNTs, and has a sheet resistance of 1-3 kΩ / sq; The average height of the pyramids in the pyramid array structure is 180 μm, and the spacing between adjacent pyramids is 50-100 μm.

7. The all-solid-state flexible organic electrochemical transistor pressure sensor according to claim 1, characterized in that: It also includes a conductive layer (7), wherein the conductive layer (7) is located between the solid electrolyte layer (5) and the gate electrode (6); The material of the conductive layer (7) includes PEDOT:PSS.

8. A method for preparing a pressure sensor of an all-solid-state flexible organic electrochemical transistor, characterized in that: Including steps: Under an inert atmosphere, NaTFSI and [EMIM][TFSI] ionic liquids are dissolved in anhydrous acetonitrile in a certain proportion, stirred, and PEO is added and continued to be stirred. The mixture is then allowed to stand and bubbles are removed before being poured into a container and dried to obtain a solid electrolyte layer (5); The PET substrate layer (1) is sequentially cleaned and treated with oxygen plasma to obtain a pretreated PET substrate layer (1); Spraying the diluted AgNW onto the pre-treated PET substrate layer (1) to form a source electrode (2) and a drain electrode (3) that are spaced apart; An ionic liquid-doped PEDOT:PSS solution is sprayed onto the source electrode (2), the drain electrode (3), and the PET substrate layer (1) between the source electrode (2) and the drain electrode (3), and annealed to form an organic semiconductor layer (4); wherein the ionic liquid comprises [EMIM][TFSI], and the mass fraction of the ionic liquid [EMIM][TFSI] in the total mass of the ionic liquid-doped PEDOT:PSS solution is 20-50 wt%; transferring the solid electrolyte layer (5) onto the organic semiconductor layer (4); Spraying CNTs on a silicon template having a pyramid array structure and then spin-coating PDMS, and curing and demoulding to form a gate electrode (6) having a pyramid array structure; Transferring the gate electrode (6) onto the solid electrolyte layer (5) so that the pyramid array structure faces the solid electrolyte layer (5); Silver paste is used to connect the wires to the source electrode (2), the drain electrode (3) and the gate electrode (6) respectively and lead them out.

9. The method for preparing a pressure sensor of an all-solid-state flexible organic electrochemical transistor according to claim 8, characterized in that: The spraying conditions of the source electrode (2) and the drain electrode (3) are as follows: the distance between the spray gun and the substrate is 10-20 cm, the spraying pressure is 1-2 bar, the spraying temperature is 90° C., and the spraying time is 15-30 s; The spraying conditions of the organic semiconductor layer (4) are as follows: the distance between the spray gun and the substrate is 10-20 cm, the spraying pressure is 1-2 bar, the spraying temperature is 100° C., and the spraying time is 15-30 s; The spraying conditions of the CNTs are as follows: the distance between the spray gun and the substrate is 10-20 cm, the spraying pressure is 1-2 bar, the spraying temperature is 90° C., and the spraying time is 60-90 s.

10. The method for preparing a pressure sensor of an all-solid-state flexible organic electrochemical transistor according to claim 8, characterized in that: Before transferring the gate electrode (6) to the solid electrolyte layer (5), the method further comprises the following steps: A PEDOT:PSS solution is sprayed on the surface of the solid electrolyte layer (5) to form a conductive layer (7).

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