A highly elastic PEDOT:PSS aerogel and its preparation method and application

Abstract

The present invention belongs to the technical field of aerogel materials and specifically discloses a highly elastic PEDOT:PSS aerogel, a preparation method thereof, and an application thereof. The present invention first mixes a PEDOT:PSS aqueous solution with an acid and stirs to obtain a mixed solution containing bubble clusters; then subjecting the mixed solution to a hydrothermal reaction to obtain a hydrogel; and then subjecting the obtained hydrogel to sequential directional freeze-drying and annealing treatments to obtain a highly elastic PEDOT:PSS aerogel. The aerogel obtained by the present invention is a single-material pure PEDOT:PSS aerogel that does not require additional material reinforcement and has the characteristics of high porosity, good elasticity, and high conductivity, as well as high compressibility, fatigue resistance, and thermal insulation. Sensors based on pure PEDOT:PSS aerogel exhibit both piezoresistive and thermoelectric effects and can be used to manufacture high-performance temperature / pressure dual-mode sensors.

Description

Technical Field

[0001] The present invention relates to the technical field of aerogel materials, and in particular to a high-elasticity PEDOT:PSS aerogel and a preparation method and application thereof. Background Art

[0002] With the rapid development of electronic technology, conductive polymer materials, with their lightweight, flexible, and biocompatible properties, have shown great potential in flexible wearable electronics, health monitoring and diagnostics, and human-computer interaction. Among them, poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid) (PEDOT:PSS) is considered the most promising conductive polymer material due to its unique electronic and ionic conductivity, flexibility, easy processability, versatility, commercial availability, and biocompatibility. Three-dimensional foam structures with low density, high porosity, high elasticity, and mechanical durability have attracted considerable attention in recent years. Unfortunately, due to its brittleness and hygroscopicity, PEDOT:PSS has primarily been used to construct high-performance electronic devices in the form of thin films or hydrogels. For three-dimensional multifunctional sensors, in particular, the three-dimensional interconnected PEDOT:PSS scaffold must possess sufficient toughness, which urgently requires the development of a new method for synthesizing high-strength PEDOT:PSS aerogels.

[0003] Generally speaking, PEDOT:PSS itself can be converted into porous aerogels, usually achieved through supercritical CO2 drying and freeze-drying. However, the resulting foam skeleton is composed of brittle PEDOT:PSS, which severely affects its toughness and compressibility. To improve performance, researchers have attempted to combine various types of reinforcing agents or support materials (such as carbon nanomaterials, polymer matrices, and cellulose nanomaterials) with PEDOT:PSS to achieve a stable network structure and mitigate the irreversible deformation caused by the inherent brittleness and hygroscopicity of PEDOT:PSS foam. However, such composite 3D aerogels more or less affect the electrical conductivity and thermoelectric properties of PEDOT:PSS itself and may bring potential problems such as uneven dispersion and mechanical mismatch. Therefore, how to provide a pure PEDOT:PSS aerogel with stable mechanical and electrical properties without the use of other ingredients is a difficult problem that needs to be solved in this field. Summary of the Invention

[0004] In view of this, the present invention provides a highly elastic PEDOT:PSS aerogel and its preparation method and application, to solve the problem that the preparation of existing elastic PEDOT:PSS aerogel requires doping with other components, and the doped components affect its electrical conductivity and thermoelectric properties.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A method for preparing a highly elastic PEDOT:PSS aerogel comprises the following steps:

[0007] 1) mixing a PEDOT:PSS aqueous solution with an acid and stirring to obtain a mixed solution containing bubble clusters;

[0008] 2) subjecting the mixed solution containing the bubble clusters to a hydrothermal reaction to obtain a hydrogel;

[0009] 3) The hydrogel obtained in step 2) is subjected to directional freeze-drying and annealing treatment in sequence to obtain a highly elastic PEDOT:PSS aerogel.

[0010] Preferably, the concentration of the acid in the mixed solution containing the bubble clusters in step 1) is 0.03 to 0.12 mol / L;

[0011] The acid includes one or more of sulfuric acid, hydrochloric acid, tannic acid, acetic acid, hydrofluoric acid and hypochlorous acid.

[0012] Preferably, the stirring speed in step 1) is 100-500 rpm, and the stirring time is 30-300 s.

[0013] Preferably, the temperature of the hydrothermal reaction in step 2) is 60-95° C., and the time of the hydrothermal reaction is 3-5 hours.

[0014] Preferably, the directional freeze-drying in step 3) is achieved by contacting the substrate with one side of the hydrogel to conduct heat, thereby achieving directional freeze-drying.

[0015] Preferably, the temperature of the directional freeze-drying is -55 to -65°C, the pressure of the directional freeze-drying is ≤10 Pa, and the time of the directional freeze-drying is 36 to 48 hours.

[0016] Preferably, the annealing temperature is 120-160° C., and the annealing time is 2-12 hours.

[0017] Preferably, the hydrogel further comprises removing the outer skin before the directional freeze-drying.

[0018] Another object of the present invention is to provide a highly elastic PEDOT:PSS aerogel prepared by the above preparation method.

[0019] Another object of the present invention is to provide a highly elastic PEDOT:PSS aerogel for use in sensors.

[0020] It can be seen from the above technical solutions that compared with the prior art, the present invention has the following beneficial effects:

[0021] The present invention introduces bubble templates and ice templates into the pure PEDOT:PSS self-assembled physically cross-linked gel, and the acid acts as both a dopant and a foaming agent, so that a single material pure PEDOT:PSS aerogel with high porosity, good elasticity and high conductivity can be obtained without the need for additional material reinforcement. The combination of soft and hard templates allows the interior of the foam to present a multi-scale pore structure with neatly arranged layered porous structures and embedded bubble cavities, resulting in the PEDOT:PSS aerogel exhibiting high compressibility, fatigue resistance and thermal insulation. Sensors based on pure PEDOT:PSS aerogel have both piezoresistive effect and thermoelectric effect, and can be used to manufacture high-performance temperature / pressure dual-mode sensors. The pressure sensor exhibits 171.23kPa -1 Ultra-high sensitivity, wide detection range of 0-3.5kPa, fast response / recovery time of less than 65ms and excellent sensing stability. At the same time, temperature sensing also has high sensitivity (18.7μV K -1 ), fast response time, and good cycling stability. Furthermore, thanks to different sensing mechanisms, sensors based on highly elastic PEDOT:PSS aerogels can simultaneously detect dual stimuli of pressure and temperature within a small pressure range. The excellent signal decoupling properties broaden the application prospects of highly elastic PEDOT:PSS aerogels in fields such as artificial intelligence, medical monitoring, and integrated soft robotics. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0023] Figure 1 These are SEM images of the highly elastic PEDOT:PSS aerogel prepared in Example 1 of the present invention at different magnifications; wherein, Figure 1 a in the figure corresponds to the SEM image at 50 times magnification. Figure 1 b in the figure corresponds to the SEM image at 300 times magnification. Figure 1 c in the figure corresponds to the SEM images at 300 times magnification at different positions;

[0024] Figure 2 This is a compression recovery performance diagram of the highly elastic PEDOT:PSS aerogel prepared in Example 1 of the present invention; wherein, Figure 2 a in the figure is the stress-strain curve at different compression cycles. Figure 2 b in the figure represents the height retention, maximum stress loss, and energy loss coefficient of the aerogel sample after different compression times;

[0025] Figure 3 This is a graph showing the thermal insulation performance of the highly elastic PEDOT:PSS aerogel prepared in Example 1 of the present invention;

[0026] Figure 4 This is a piezoresistive characteristic diagram of the highly elastic PEDOT:PSS aerogel prepared in Example 1 of the present invention; wherein, Figure 4 a is the piezoresistive sensitivity of the pressure sensor of the highly elastic PEDOT:PSS aerogel, Figure 4 b is the resistance response time and recovery time of the pressure sensor of highly elastic PEDOT:PSS aerogel, Figure 4 c in the figure is the real-time resistance change of the pressure sensor of the highly elastic PEDOT:PSS aerogel under compression at different frequencies. Figure 4 d in the figure is the real-time resistance change of the pressure sensor of the highly elastic PEDOT:PSS aerogel under different pressure compressions;

[0027] Figure 5 This is a temperature-sensitive characteristic diagram of the highly elastic PEDOT:PSS aerogel prepared in Example 1 of the present invention; wherein, Figure 5 a is the temperature sensitivity of the temperature sensor of the highly elastic PEDOT:PSS aerogel, Figure 5 b in the figure is the voltage value of the temperature sensor of the highly elastic PEDOT:PSS aerogel under continuous temperature gradients. Figure 5 Figure c represents the changes in voltage and resistance of the temperature sensor of highly elastic PEDOT:PSS aerogel under constant pressure and continuous pressure at a fixed temperature difference. DETAILED DESCRIPTION

[0028] The present invention provides a method for preparing a highly elastic PEDOT:PSS aerogel, and the preparation steps are as follows:

[0029] 1) mixing a PEDOT:PSS aqueous solution with an acid and stirring to obtain a mixed solution containing bubble clusters;

[0030] 2) subjecting the mixed solution to a hydrothermal reaction to obtain a hydrogel;

[0031] 3) The hydrogel obtained in step 2) is subjected to directional freeze-drying and annealing treatment in sequence to obtain a highly elastic PEDOT:PSS aerogel.

[0032] In the present invention, the concentration of the PEDOT:PSS aqueous solution is preferably 1.3 wt %.

[0033] In the present invention, the PEDOT:PSS aqueous solution further includes filtering and ultrasonic treatment in sequence before mixing with the acid.

[0034] In the present invention, the filtration is preferably carried out using a PVDF microporous filter, and the filtration pore size is preferably 0.45 μm.

[0035] In the present invention, the power of the ultrasonic treatment is preferably 60-120 W, specifically 70 W, 80 W, 90 W, 100 W, and 110 W; the time of the ultrasonic treatment is preferably 5-30 min, specifically 10 min, 15 min, 20 min, and 25 min.

[0036] In the present invention, the concentration of acid in the mixed solution containing bubble clusters in step 1) is 0.03-0.12 mol / L, specifically 0.04 mol / L, 0.05 mol / L, 0.06 mol / L, 0.08 mol / L, or 0.1 mol / L.

[0037] In the present invention, the acid includes one or more of sulfuric acid, hydrochloric acid, tannic acid, acetic acid, hydrofluoric acid and hypochlorous acid.

[0038] In the present invention, the stirring speed in step 1) is 100-500 rpm, specifically 120 rpm, 150 rpm, 180 rpm, 200 rpm, 250 rpm, 300 rpm, 350 rpm, 400 rpm, or 450 rpm; the stirring time is 30-300 s, specifically 60 s, 90 s, 120 s, 150 s, 180 s, 210 s, 240 s, or 270 s.

[0039] In the present invention, the temperature of the hydrothermal reaction in step 2) is 60-95°C, specifically 65°C, 70°C, 75°C, 80°C, 85°C, or 90°C; the time of the hydrothermal reaction is 3-5h, specifically 3.5h, 4h, or 4.5h.

[0040] In the present invention, the directional freeze-drying in step 3) is achieved by utilizing the contact between the substrate and one side of the hydrogel to conduct heat and thus realize directional freeze-drying.

[0041] In the present invention, the substrate is preferably a copper block.

[0042] In the present invention, the hydrogel is preferably placed on a copper block, which is placed in liquid nitrogen, and the hydrogel is not in contact with the liquid nitrogen.

[0043] In the present invention, it is preferred that the side surface of the hydrogel be in contact with the copper block, where the side surface is the surface of the hydrogel perpendicular to the vertical direction. For example, the side surface of a cylindrical hydrogel prepared in a cylindrical container is the side surface of the cylinder, not the circular bottom surface.

[0044] In the present invention, the temperature of the directional freeze-drying is -55 to -65°C, specifically -56°C, -58°C, -60°C, -62°C, and -64°C; the pressure of the directional freeze-drying is ≤10Pa, specifically 0.1Pa, 1Pa, 2Pa, 4Pa, 5Pa, 6Pa, and 8Pa; the time of the directional freeze-drying is 36 to 48h, specifically 38h, 40h, 42h, 44h, 45h, and 46h.

[0045] In the present invention, the annealing temperature is 120-160°C, specifically 125°C, 130°C, 135°C, 140°C, 145°C, 150°C, 155°C; the annealing time is 2-12h, specifically 4h, 5h, 6h, 8h, 10h.

[0046] In the present invention, the annealing treatment is preferably performed under an inert atmosphere, which includes one or more of a nitrogen atmosphere and a rare gas atmosphere.

[0047] In the present invention, the outer skin of the hydrogel is removed before the directional freeze-drying.

[0048] In the present invention, the outer skin is the outermost layer of the hydrogel, and the thickness of the outer skin is not zero.

[0049] The present invention also provides a high-elasticity PEDOT:PSS aerogel prepared by the above preparation method.

[0050] The present invention also provides an application of a highly elastic PEDOT:PSS aerogel in a sensor.

[0051] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0052] Example 1

[0053] A certain amount of PEDOT:PSS aqueous solution (Heraeus PH1000 model) was filtered through a PVDF microporous filter (pore size 0.45 μm) and ultrasonically treated at 100 W for 20 minutes. The treated PEDOT:PSS aqueous solution was magnetically stirred and a certain amount of sulfuric acid was added while stirring to mix the two (control the acid concentration to 0.12 mol / L) to obtain a mixed solution.

[0054] The resulting mixed solution was stirred at 500 rpm for 120 seconds to obtain a mixed solution containing bubble clusters. The solution was then quickly transferred to a polytetrafluoroethylene container and subjected to a hydrothermal reaction in an oven at 90°C for 4 hours, forming a cylindrical hydrogel. The hydrogel was washed with deionized water, and the outer surface of the hydrogel was removed (cutting off with a knife).

[0055] The treated hydrogel was directionally freeze-dried at -60°C and 8 Pa for 40 hours (the directional freeze-drying technology is to place the treated hydrogel on its side on a copper block, which is placed in liquid nitrogen), and then annealed at 150°C under helium gas for 6 hours to obtain a highly elastic PEDOT:PSS aerogel with a porosity of >99%.

[0056] Example 2

[0057] A certain amount of PEDOT:PSS aqueous solution (Heraeus PH1000) was filtered through a PVDF microporous filter (pore size 0.45 μm) and ultrasonically treated at 70 W for 25 minutes. The treated PEDOT:PSS aqueous solution was magnetically stirred and a certain amount of hydrofluoric acid was added while stirring to mix the two (control the acid concentration to 0.08 mol / L) to obtain a mixed solution.

[0058] The resulting mixed solution was stirred at 100 rpm for 200 seconds to obtain a mixed solution containing bubble clusters. The solution was then quickly transferred to a polytetrafluoroethylene container and subjected to a hydrothermal reaction in an oven at 60°C for 5 hours, forming a cylindrical hydrogel. The hydrogel was washed with deionized water, and the outer surface of the hydrogel was removed (cutting off with a knife).

[0059] The treated hydrogel was directionally freeze-dried at -60°C and 10 Pa for 48 hours (the directional freeze-drying technology is to place the treated hydrogel on its side on a copper block, which is placed in liquid nitrogen), and then annealed at 120°C under helium gas for 12 hours to obtain a highly elastic PEDOT:PSS aerogel with a porosity of >99%.

[0060] Example 3

[0061] A certain amount of PEDOT:PSS aqueous solution (Heraeus PH1000) was filtered through a PVDF microporous filter (pore size 0.45 μm) and sonicated at 120 W for 5 minutes. The treated PEDOT:PSS aqueous solution was magnetically stirred, and a certain amount of sulfuric acid was added while stirring to mix the two (control the acid concentration to 0.03 mol / L) to obtain a mixed solution.

[0062] The resulting mixed solution was stirred at 300 rpm for 120 seconds to obtain a mixed solution containing bubble clusters. The solution was then quickly transferred to a polytetrafluoroethylene container and subjected to a hydrothermal reaction in an oven at 90°C for 3 hours, forming a cylindrical hydrogel. The hydrogel was washed with deionized water, and the outer surface of the hydrogel was removed (cutting off with a knife).

[0063] The treated hydrogel was directionally freeze-dried at -60°C and 5Pa for 36 hours (the directional freeze-drying technology is to place the treated hydrogel on its side on a copper block, which is placed in liquid nitrogen), and then annealed at 160°C for 2 hours under helium gas to obtain a highly elastic PEDOT:PSS aerogel with a porosity of >99%.

[0064] Example 4

[0065] A certain amount of PEDOT:PSS aqueous solution (Heraeus PH1000) was filtered through a PVDF microporous filter (pore size 0.45 μm) and sonicated at 80 W for 15 minutes. The treated PEDOT:PSS aqueous solution was magnetically stirred and a certain amount of acetic acid was added while stirring to mix the two (control the acid concentration to 0.12 mol / L) to obtain a mixed solution.

[0066] The resulting mixed solution was stirred at 500 rpm for 30 seconds to obtain a mixed solution containing bubble clusters. The solution was then quickly transferred to a polytetrafluoroethylene container and subjected to a hydrothermal reaction in an oven at 80°C for 4 hours, forming a cylindrical hydrogel. The hydrogel was washed with deionized water, and the outer surface of the hydrogel was removed (cutting off with a knife).

[0067] The treated hydrogel was directionally freeze-dried at -60°C and 5 Pa for 42 hours (the directional freeze-drying technology is to place the treated hydrogel on its side on a copper block, which is placed in liquid nitrogen), and then annealed at 140°C for 8 hours under helium gas to obtain a highly elastic PEDOT:PSS aerogel with a porosity of >99%.

[0068] Experimental Example 1

[0069] The SEM images of the highly elastic PEDOT:PSS aerogel prepared in Example 1 at different magnifications are shown in FIG. Figure 1 As shown, Figure 1 The a in the number corresponds to 50 times, Figure 1 The b in the equation corresponds to 300 times. Figure 1 The c in the equation corresponds to 300 times, from Figure 1 It can be seen that the interior of the PEDOT:PSS aerogel prepared by the present invention is composed of oriented pores and bubble cavities.

[0070] The compression recovery performance of the highly elastic PEDOT:PSS aerogel prepared in Example 1 was tested by using a universal testing machine to compress the aerogel sample at a speed of 0.05 mm / s to a compression degree of 50%, while recording the change in force. Figure 2 As shown, Figure 2 a in the figure is the stress-strain curve at 1, 50, 100, and 200 compression cycles. Figure 2 b in the figure represents the height retention, maximum stress loss and energy loss coefficient of the aerogel sample after different compression times. Figure 2 It can be seen that the aerogel's height retention reaches 96.7% and its stress remains at 91% of its original stress, indicating minimal damage to the internal structure. Furthermore, due to effective stress transfer, the aerogel's energy loss coefficient remains at 0.5, resulting in minimal energy dissipation.

[0071] The thermal insulation performance of the highly elastic PEDOT:PSS aerogel prepared in Example 1 was tested by placing the aerogel on a hot plate at a set temperature and photographing the surface temperature of the aerogel with an infrared thermal imager. Figure 3 As shown, through Figure 3 It can be seen that on a 150°C hot plate, the instantaneous surface temperature of the PEDOT:PSS aerogel is 44.3°C, rising to 48.4°C after ten minutes. On a 200°C hot plate, the instantaneous temperature rises from 63.2°C to 69.5°C after ten minutes. This demonstrates that the prepared aerogel has excellent thermal insulation properties over a wide temperature range.

[0072] The piezoresistive properties of the highly elastic PEDOT:PSS aerogel prepared in Example 1 were tested by connecting the aerogel to a multimeter and monitoring its resistance change while compressing it. Figure 4 As shown, Figure 4 a is the piezoresistive sensitivity of the pressure sensor based on PEDOT:PSS aerogel, Figure 4 b in the figure is the resistance response time and recovery time of the pressure sensor based on PEDOT:PSS aerogel. Figure 4 c in the figure is the real-time resistance change of the pressure sensor based on PEDOT:PSS aerogel under compression at different frequencies. Figure 4 The d in the figure is the real-time resistance change of the pressure sensor based on PEDOT:PSS aerogel under different pressure compression. Figure 4 It can be seen that the piezoresistive sensitivity of the pressure sensor based on PEDOT:PSS aerogel is divided into three linear regions. The sensitivities in the pressure ranges of 0-0.28kPa, 0.28-1.26kPa and 1.26-3.5kPa are 171.23, 32.74 and 4.9kPa respectively. -1. Obviously, based on the unique bubble-enhanced layered porous structure and excellent conductivity of aerogel, the sensor can show ultra-high sensitivity under ultra-low pressure conditions. The pressure sensor can continuously detect the pressure change process from a small pressure of 50Pa to a gradual increase of 2kPa, and the relative resistance decreases steadily with the increase of pressure. Even under rapid pressing at different frequencies and degrees, the sensor still maintains an excellent real-time monitoring capability. Thanks to the multi-scale pore structure inside the aerogel, it can show a fast response time (52ms) and recovery time (62ms).

[0073] The temperature-sensing properties of the highly elastic PEDOT:PSS aerogel prepared in Example 1 were tested by providing a temperature difference between the upper and lower ends of the aerogel using a temperature controller and measuring the voltage generated by the aerogel using a multimeter. Figure 5 As shown, Figure 5 a in the figure is the temperature sensitivity of the temperature sensor based on PEDOT:PSS aerogel. Figure 5 b in the figure is the voltage value of the temperature sensor based on PEDOT:PSS aerogel under continuous temperature gradients. Figure 5 c is the change of voltage and resistance value of the temperature sensor based on PEDOT:PSS aerogel under fixed temperature difference, continuous pressing and continuous pressing. Figure 5 It can be seen that the temperature sensitivity of the temperature sensor based on PEDOT:PSS aerogel is 18.7μVK -1 . When the temperature gradient increases continuously from 5K to 30K, the temperature sensor exhibits a stable voltage output characteristic. This shows that it can accurately detect a wide range of temperature changes. Under a constant temperature gradient of 10K, a constant pressure and a continuous cyclic pressure are applied to the sensor respectively. As can be seen from the figure, the output voltage of the sensor gradually rises to a stable value as the temperature gradient increases, and is not affected by the pressure. At the same time, the relative resistance change does not cause a mismatch in dynamic pressure detection due to the generation of the temperature gradient. The above results show that the sensor based on PEDOT:PSS aerogel has good dual-mode sensing decoupling capability.

[0074] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0075] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing highly elastic PEDOT:PSS aerogel, characterized in that: The method comprises the following preparation steps: 1) mixing a PEDOT:PSS aqueous solution with an acid and stirring to obtain a mixed solution containing bubble clusters; 2) subjecting the mixed solution containing the bubble clusters to a hydrothermal reaction to obtain a hydrogel; 3) performing directional freeze-drying and annealing treatment on the hydrogel obtained in step 2) to obtain a highly elastic PEDOT:PSS aerogel; Highly elastic PEDOT:PSS aerogel is applied to temperature / pressure dual-mode sensors.

2. The method for preparing a highly elastic PEDOT:PSS aerogel according to claim 1, characterized in that: The concentration of the acid in the mixed solution containing the bubble clusters in step 1) is 0.03-0.12 mol / L; The acid includes one or more of sulfuric acid, hydrochloric acid, tannic acid, acetic acid, hydrofluoric acid and hypochlorous acid.

3. The method for preparing a highly elastic PEDOT:PSS aerogel according to claim 2, characterized in that: In the step 1), the stirring speed is 100-500 rpm, and the stirring time is 30-300 s.

4. The method for preparing a highly elastic PEDOT:PSS aerogel according to any one of claims 1 to 3, characterized in that: The temperature of the hydrothermal reaction in step 2) is 60-95° C., and the time of the hydrothermal reaction is 3-5 hours.

5. The method for preparing a highly elastic PEDOT:PSS aerogel according to claim 4, characterized in that: The directional freeze-drying in step 3) is achieved by utilizing the contact between the substrate and one side of the hydrogel to conduct heat and thus realize directional freeze-drying.

6. The method for preparing a highly elastic PEDOT:PSS aerogel according to claim 5, characterized in that: The temperature of the directional freeze drying is -55 to -65°C, the pressure of the directional freeze drying is ≤10Pa, and the time of the directional freeze drying is 36 to 48 hours.

7. The method for preparing a highly elastic PEDOT:PSS aerogel according to claim 5 or 6, characterized in that: The annealing temperature is 120-160° C., and the annealing time is 2-12 hours.

8. The method for preparing a highly elastic PEDOT:PSS aerogel according to claim 7, characterized in that: The method further comprises removing the outer skin of the hydrogel before the directional freeze drying.

9. Highly elastic PEDOT:PSS aerogel prepared by the preparation method according to any one of claims 1 to 8.

10. Use of the highly elastic PEDOT:PSS aerogel according to claim 9 in a sensor.

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