Highly tensile and highly conductive hydrogels with layered structures, their preparation methods and applications

Abstract

The application discloses a kind of high tensile high conductive hydrogel with layered structure and its preparation method and application.The method mixes PVA, PEDOT:PSS with EGaIn microparticles, and is prepared by the way of gravity settlement and electrostatic adsorption auxiliary settlement, and the hydrogel with layered structure is obtained.By controlling the proportion of PVA, PEDOT:PSS solution and EGaIn microparticles, the conductive hydrogel with layered structure prepared shows good conductive capacity and mechanical behavior, and can work normally under larger strain and stress conditions, and has wide application prospect in the field of flexible stretchable electronic devices.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of flexible conductive materials, and relates to a high-stretching and high-conducting hydrogel with a layered structure and a preparation method and application thereof. BACKGROUND

[0002] Hydrogels are considered as promising candidates for building soft electronic devices and biomedical devices due to their mechanical flexibility, structural permeability and biocompatibility. However, most hydrogels are not conductive, which limits their application in these fields. The research and development of conductive hydrogels create new possibilities for their application in advanced technology fields, such as implantable bioelectrodes, soft actuators and tissue engineering platforms. Despite extensive research, it is still challenging to achieve high conductivity and mechanical robustness in hydrogels. Traditional ionically conductive hydrogels achieve ion conduction by introducing electrolytes into the aqueous phase, which leads to densification of the polymer network structure due to the Hofmeister effect, and the mechanical properties of ionically conductive hydrogels are enhanced by increasing the crosslinking density. However, due to the solubility of electrolytes and low ion mobility, ionically conductive hydrogels usually exhibit a conductivity of 10 S·m -1 or less, which is several orders of magnitude lower than electronic conductors, greatly limiting the application range of conductive hydrogels.

[0003] To improve the conductivity of hydrogels, adding electronic conductive components can effectively improve the conductivity. The traditional method is to add conductive fillers such as metals or carbon fillers to the hydrogel matrix. However, due to the random distribution of conductive fillers in the hydrogel matrix, it is difficult to construct a three-dimensional conductive network at a low content level (e.g. <10wt%). While adding too much conductive filler will destroy the uniformity of the hydrogel structure, leading to stress concentration, thus causing the failure of the conductive hydrogel at a small strain. Another method to improve the conductivity of hydrogels is to add conductive polymers such as poly(3,4-ethylenedioxythiophene) or polyaniline, which can form a fibrous three-dimensional conductive network in the hydrogel, or attach to the original polymer network to construct a three-dimensional conductive network. Compared with adding conductive fillers, the three-dimensional conductive network formed by conductive polymers has better uniformity and mechanical properties, providing better ductility. However, due to the inherent properties of conductive polymers, the conductivity of related hydrogels is usually limited to 1,000 S·m -1 or less.

[0004] Liquid metal (LM) such as eutectic gallium-indium alloy (EGaIn) has attracted extensive attention in recent years due to its non-toxicity, high thermal and electrical conductivity, large surface tension, low vapor pressure and low viscosity. Although important progress has been made in integrating liquid metal with hydrogels, each material system still needs to make a trade-off between meeting the high conductivity requirements of commercial electronic components and the flexibility and deformability of hydrogels.

[0005] Yan team prepared IM conductive elastomers by adding ultrasonic treated EGaIn nanoparticles into polyvinyl alcohol (PVA), which achieved 50 times larger ductility, but the material's conductivity was poor, which could not meet the application of high-conductive devices (Wang X, Zheng S, Xiong J, et al. Stretch-Induced Conductivity Enhancement in Highly Conductive and Tough Hydrogels [J]. Advanced Materials, 2024: 2313845).

[0006] Xuan team introduced microchannels into PDMS elastomers, and realized reversible circuit conduction through microchannels between LM droplets, which could be applied to switches and other devices under small stress, but the material had low ductility and failed under large stress, which could not meet the requirements of wearable devices (He X, Wu J, Xuan S, et al. Stretchable and recyclable liquid metal droplets embedded elastomer composite with high mechanically sensitive conductivity [J]. ACS Applied Materials & Interfaces, 2022, 14(7): 9597-9607).

[0007] Therefore, it has good scientific significance and application prospect to develop a simple method to prepare liquid metal-based conductive hydrogel with good mechanical behavior and conductivity. SUMMARY

[0008] The application aims to provide a high-stretch and high-conductivity hydrogel with a layered structure and a preparation method and application thereof. The hydrogel takes polyvinyl alcohol and PEDOT:PSS as monomer solutions, adds EGaIn micro-nanoparticles after mixing, obtains a mixed solution after ultrasonic dispersion, and obtains the high-stretch and high-conductivity hydrogel with a layered structure after injection molding. The PEDOT:PSS nanoparticles have a Zeta potential opposite to that of the liquid metal particles, can be adsorbed with the liquid metal particles, and promote the deposition of smaller size liquid metal particles. The deposited liquid metal forms a dense conductive layer at the bottom, which provides excellent conductivity for the hydrogel. At the same time, the liquid metal nanoparticles dispersed in the PVA hydrogel layer together with the PEDOT:PSS nanoparticles and PVA crystalline domains serve as crosslinking points to improve the mechanical properties of the material. The hydrogel prepared by the application has a typical layered structure, good mechanical properties and conductivity, and can meet the use requirements of different scenes, thereby expanding the working range and application scenarios of the flexible electronic devices based on the conductive hydrogel.

[0009] The technical solution for achieving the object of the application is as follows:

[0010] The preparation method of the high-stretch and high-conductivity hydrogel with a layered structure specifically comprises the following steps:

[0011] (1) The monomer solution is obtained by adding 1.0% PEDOT:PSS solution in the PVA solution according to the mass ratio of PEDOT:PSS solution to PVA of 1:1-3:1, and then adding water and stirring uniformly;

[0012] (2) The mixed solution is obtained by adding EGaIn micro-nanoparticles in the monomer solution according to the mass ratio of EGaIn micro-nanoparticles to PVA of 0.5-1.5:1, and then ultrasonic dispersion;

[0013] (3) The mixed solution is injected into a mold, heated and solidified at 70±5℃ for 30-40min, and then demolded to obtain the high-stretch and high-conductivity hydrogel with a layered structure.

[0014] Preferably, in step (1), the mass concentration of the PVA solution is 10%, and the mass ratio of PEDOT:PSS solution to PVA is 2:1.

[0015] Preferably, in step (1), the mass ratio of PVA to water in the monomer solution is 0.1:1.494.

[0016] The application further provides the high-stretch and high-conductivity hydrogel with a layered structure prepared by the above preparation method.

[0017] Further, the application provides the use of the high-stretch and high-conductivity hydrogel with a layered structure in the preparation of a flexible wearable capacitive sensor.

[0018] Preferably, the specific method of the use is that two hydrogel layers of the high-stretch and high-conductivity hydrogel with a layered structure are contacted with each other, the conductive layers of the two hydrogels are used as the upper and lower electrodes of the sensor respectively, and then a VHB tape is used for packaging, so that a flexible wearable capacitive sensor is prepared.

[0019] Further, the application provides the use of the high-stretch and high-conductivity hydrogel with a layered structure in the preparation of a biological electrode.

[0020] The hydrogel prepared by the application is a conductive hydrogel with a layered structure, has a unique composition, and has EGaIn micro / nano droplets on one side and a polyvinyl alcohol hydrogel on the other side. In order to achieve high conductivity in the liquid metal conductive layer and prevent liquid metal particles (LMPs) from gathering in the PVA hydrogel, PEDOT: PSS nanoparticles with opposite Zeta potential to the LMPs are introduced. Under the combined action of gravity sedimentation and electrostatic auxiliary sedimentation, the liquid metal conductive layer forms a network with large particle liquid metal particles as the main framework and small particles as the network interconnectors.

[0021] Compared with the prior art, the application has the following advantages:

[0022] (1) In order to achieve high conductivity in the liquid metal conductive layer and prevent liquid metal particles from gathering in the hydrogel layer, the application introduces PEDOT: PSS nanoparticles with opposite Zeta potential to the LMPs into the hydrogel precursor solution. The introduction of PEDOT: PSS nanoparticles allows electrostatic adsorption on the surface of small liquid metal particles, and auxiliary sedimentation is achieved by increasing the size of the liquid metal particles.

[0023] (2) Under the combined action of gravity sedimentation and electrostatic auxiliary sedimentation, the liquid metal conductive layer forms a network with large liquid metal particles as the main framework and small particles as the conductive network interconnectors. The liquid metal layer with this configuration has excellent conductivity (1.67*10 5 S·m -1 ) and maintains stable resistance under a tensile strain of 617%.

[0024] (3) Due to the existence of various cross-linking mechanisms, including PVA crystalline domains, PEDOT: PSS nanoparticles and liquid metal particles, the prepared conductive hydrogel exhibits high Young's modulus (~ 178.14 MPa), stretchability (~ 818%) and toughness (~ 185.9 MJ·m -3), which is superior to most existing tough gels, biological tissues and natural rubbers.

[0025] (4) The unique layered structure of the hydrogel of the present application enables the flexible wearable capacitive sensor assembled therefrom to have excellent sensing performance. The flexible wearable capacitive sensor is prepared by laminating two pieces of the layered conductive hydrogel, wherein the PVA hydrogel layer can serve as the dielectric layer of the capacitive sensor due to its insulating property, and thus the PVA hydrogel layers are in contact with each other during the lamination process, and the liquid metal conductive layer serves as the upper and lower electrodes of the capacitive sensor and transmits signals through external wires. This capacitive sensor, which is assembled without an additional dielectric layer, has ultra-thin and ultra-fast detection capability, and can accurately and quickly (~ 20 ms) detect the movement of different joint parts of the human body during the test, and can generate a signal corresponding to a 0.05 g micro-mass object.

[0026] (5) The hydrogel of the present application can also be used to prepare a bioelectrode, which can accurately monitor human movement and bioelectric signals, such as attaching around the human eye to measure the electrooculogram EOG, or attaching to the pulse of the human wrist to measure the electrocardiogram ECG, and exhibits high sensitivity and accuracy, showing great application potential in the field of soft electronics and wearable technology. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is a structural diagram of the layered conductive hydrogel;

[0028] Figure 2 is a tensile stress-strain curve of the layered conductive hydrogel prepared in Examples 1-7;

[0029] Figure 3 is a toughness and elastic modulus graph of the layered conductive hydrogel prepared in Examples 1-7;

[0030] Figure 4 is a stress-strain curve of the layered conductive hydrogel prepared in Examples 3, 8-11;

[0031] Figure 5 is a toughness and elastic modulus graph of the layered conductive hydrogel prepared in Examples 3, 8-11;

[0032] Figure 6 is an initial resistance graph of the layered conductive hydrogel prepared in Examples 3, 9-11;

[0033] Figure 7 is a tensile resistance graph of the layered conductive hydrogel prepared in Examples 3, 9-11;

[0034] Figure 8This is a graph showing the relative change rate of resistance of the conductive hydrogel with a layered structure prepared in Example 10 under heavy pressure.

[0035] Figure 9 This is a graph showing the relative change rate of resistance of the conductive hydrogel with a layered structure prepared in Example 10 when it is bent.

[0036] Figure 10 This is a graph showing the relative change rate of resistance of the conductive hydrogel with a layered structure prepared in Example 10 during torsion;

[0037] Figure 11 The response curve of the capacitance change of the flexible capacitive sensor prepared based on the conductive hydrogel with a layered structure as the finger is bent, as shown in Example 10.

[0038] Figure 12 The response curve of the flexible capacitive sensor prepared based on a conductive hydrogel with a layered structure, as the knee bends, is shown in Example 10.

[0039] Figure 13 The response curve of the flexible capacitive sensor prepared based on the conductive hydrogel with a layered structure, as a function of swallowing, is shown in Example 10.

[0040] Figure 14 The response time curve of the flexible capacitive sensor prepared based on the conductive hydrogel with a layered structure, as described in Example 10, under a single press.

[0041] Figure 15 The capacitance change response curves of the flexible capacitive sensor prepared based on the conductive hydrogel with a layered structure, as described in Example 10, are shown below under different pressing times.

[0042] Figure 16 The capacitance change response curves of the flexible capacitive sensor prepared in Example 10 based on a conductive hydrogel with a layered structure under different pressures are shown.

[0043] Figure 17 The EOG signal test curve is based on the conductive hydrogel with a layered structure prepared in Example 10.

[0044] Figure 18 The ECG signal test curve is based on the bioelectrode prepared in Example 10, which is a conductive hydrogel with a layered structure. Detailed Implementation

[0045] The technical solutions of the present application are further described below in combination with the drawings and specific embodiments, but are not limited thereto. Any modification or equivalent replacement of the technical solutions of the present application without departing from the spirit and scope of the present application shall be covered in the protection scope of the present application.

[0046] Preparation of hydrogel PLSM 0.5

[0047] (1) 1.0 g of PVA was dissolved in 9 g of deionized water at 90°C to obtain a PVA solution with a concentration of 10%. 0.594 g of deionized water was added to a glass bottle and continuously stirred at a speed of 1500 rpm for 30 min to obtain a monomer solution.

[0048] (2) 0.05 g of EGaIn micro-nanoparticles was added to 1.0 g of the PVA solution, and a mixed solution was obtained after ultrasonic dispersion.

[0049] (3) The mixed solution was injected into a mold, and after heating and curing at 70±5°C for 30-40 min, the mold was removed to obtain a conductive hydrogel PLSM 0.5 .

[0050] Preparation of hydrogel PPS1LM with layered structure and high stretchability and high conductivity 0.5

[0051] (1) 1.0 g of PVA was dissolved in 9 g of deionized water at 90°C to obtain a PVA solution with a concentration of 10%. According to the mass ratio of PEDOT:PSS solution to PVA of 1:1, 1.0 g of PVA solution, 0.1 g of PEDOT:PSS solution with a mass concentration of 1%, and 0.495 g of deionized water were continuously stirred at a speed of 1500 rpm for 30 min and added to a glass bottle to obtain a monomer solution.

[0052] (2) 0.05 g of EGaIn micro-nanoparticles was added to the monomer solution, and a mixed solution was obtained after ultrasonic dispersion.

[0053] (3) The mixed solution was injected into a mold, and after heating and curing at 70±5°C for 30-40 min, the mold was removed to obtain a conductive hydrogel PPS1LM with layered structure 0.5 .

[0054] Preparation of hydrogel PPS2LM with layered structure and high stretchability and high conductivity 0.5

[0055] ​​​The embodiment is basically the same as embodiment 2, except that the mass ratio of PEDOT:PSS solution to PVA in step (1) is 2:1, and specifically: 1.0 g of PVA solution, 0.2 g of PEDOT:PSS solution with a mass concentration of 1%, and 0.396 g of deionized water are continuously stirred at a speed of 1500 rpm for 30 min and added into a glass bottle to obtain a monomer solution.

[0056] Preparation of high-stretching and high-conducting hydrogel PPS3LM with layered structure 0.5 Preparation of high-stretching and high-conducting hydrogel PPS3LM with layered structure

[0057] The embodiment is basically the same as embodiment 2, except that the mass ratio of PEDOT:PSS solution to PVA in step (1) is 3:1, and specifically: 1.0 g of PVA solution, 0.3 g of PEDOT:PSS solution with a mass concentration of 1%, and 0.297 g of deionized water are continuously stirred at a speed of 1500 rpm for 30 min and added into a glass bottle to obtain a monomer solution.

[0058] Preparation of high-stretching and high-conducting hydrogel PPS4LM with layered structure 0.5 Preparation of high-stretching and high-conducting hydrogel PPS4LM with layered structure

[0059] The embodiment is basically the same as embodiment 2, except that the mass ratio of PEDOT:PSS solution to PVA in step (1) is 4:1, and specifically: 1.0 g of PVA solution, 0.4 g of PEDOT:PSS solution with a mass concentration of 1%, and 0.198 g of deionized water are continuously stirred at a speed of 1500 rpm for 30 min and added into a glass bottle to obtain a monomer solution.

[0060] Preparation of high-stretching and high-conducting hydrogel PPS5LM with layered structure 0.5 Preparation of high-stretching and high-conducting hydrogel PPS5LM with layered structure

[0061] The embodiment is basically the same as embodiment 2, except that the mass ratio of PEDOT:PSS solution to PVA in step (1) is 5:1, and specifically: 1.0 g of PVA solution, 0.5 g of PEDOT:PSS solution with a mass concentration of 1%, and 0.099 g of deionized water are continuously stirred at a speed of 1500 rpm for 30 min and added into a glass bottle to obtain a monomer solution.

[0062] Preparation of high-stretching and high-conducting hydrogel PPS6LM with layered structure 0.5 Preparation of high-stretching and high-conducting hydrogel PPS6LM with layered structure

[0063] This embodiment is basically the same as embodiment 2, except that in step (1), the mass ratio of PEDOT:PSS solution to PVA is 6:1. Specifically, according to the mass ratio of PEDOT:PSS solution to PVA of 6:1, 1.0g of PVA solution and 0.6g of PEDOT:PSS solution with a mass concentration of 1% are added to a glass bottle and stirred continuously at 1500rpm for 30min to obtain a monomer solution.

[0064] Mechanical property testing of conductive hydrogels with layered structures and different monomer ratios

[0065] Mechanical property tests were performed on the hydrogels with layered structures obtained in Examples 1-7, and their stress-strain curves are shown below. Figure 2 As shown, the toughness and modulus diagrams are as follows: Figure 3 As shown, the fracture strain range of the conductive hydrogel with a layered structure is 200%–770%. With increasing PEDOT:PSS monomer ratio, the fracture strain of the conductive hydrogel with a layered structure decreases, while the toughness initially increases but then decreases, although the modulus increases. This is because PEDOT:PSS, as a nanofiller, can coordinate with PVA to form crosslinking points. Therefore, with increasing PEDOT:PSS content, the crosslinking density of PVA increases. Furthermore, due to the rigidity of PEDOT:PSS, the ductility of the conductive hydrogel with a layered structure continuously decreases while its strength continuously increases. When the mass ratio of PEDOT:PSS solution to PVA is 2:1, the conductive hydrogel with a layered structure exhibits the greatest toughness; therefore, this ratio was chosen for subsequent tests.

[0066] Example 8: Preparation of PPS2LM0 hydrogel with a layered structure

[0067] (1) Dissolve 1.0g PVA in 9g deionized water at 90℃ to obtain a 10% PVA solution. According to the mass ratio of PEDOT:PSS solution to PVA of 2:1, add 1.0g PVA solution, 0.2g PEDOT:PSS solution with a mass concentration of 1% and 0.396g deionized water to a glass bottle while stirring continuously at 1500rpm for 30min to obtain a monomer solution.

[0068] (2) The above mixed solution is injected into the mold, and after being heated and cured at 70±5℃ for 30 to 40 minutes, it is demolded to obtain a conductive hydrogel with high mechanical properties and a layered structure.

[0069] Example 9: Highly tensile and highly conductive hydrogel PPS2LM with a layered structure 1.0 Preparation

[0070] This embodiment is basically the same as embodiment 3, except that the mass ratio of EGaIn micro-nano particles to PVA in step (2) is 1:1. Specifically, 0.1g of EGaIn micro-nano particles are added to the monomer solution and then ultrasonically dispersed to obtain a mixed solution.

[0071] Example 10: Highly tensile and highly conductive hydrogel PPS2LM with a layered structure 1.5 Preparation

[0072] This embodiment is basically the same as embodiment 3, except that the mass ratio of EGaIn micro / nanoparticles to PVA in step (2) is 1.5:1. Specifically, 0.15g of EGaIn micro / nanoparticles is added to the monomer solution and then ultrasonically dispersed to obtain a mixed solution.

[0073] Example 11 Preparation of PPS2LM2 hydrogel with layered structure

[0074] This embodiment is basically the same as embodiment 3, except that the mass ratio of EGaIn micro-nano particles to PVA in step (2) is 2:1. Specifically, 0.2g of EGaIn micro-nano particles are added to the monomer solution and then ultrasonically dispersed to obtain a mixed solution.

[0075] Mechanical property testing of conductive hydrogels with layered structures and high mechanical properties at different monomer concentrations

[0076] Mechanical properties were tested on the conductive hydrogels with layered structures obtained in Examples 3, 8, 9, 10, and 11, and their stress-strain curves are shown below. Figure 4 As shown, with the increase of the EGaIn micro / nanoparticle content, the fracture strain of the layered conductive hydrogel first increases and then decreases. When the mass ratio of EGaIn micro / nanoparticles to PVA is 1.5, the fracture strain of the conductive hydrogel reaches a maximum of 820%. This is because EGaIn micro / nanoparticles have a low modulus. The EGaIn micro / nanoparticles located in the PVA polymer layer can coordinate with the hydroxyl groups on the PVA. When the material is deformed by external force, the EGaIn micro / nanoparticles can deform along the tensile direction, playing a role in stress dissipation, thus improving the ductility of the layered conductive hydrogel. However, with the increase of EGaIn micro / nanoparticle content, too many particles will destroy the PVA network, forming defects and causing a decrease in the mechanical properties of the PPSLM gel.

[0077] Electrical property testing of conductive hydrogels with layered structures and high mechanical properties at different monomer concentrations

[0078] The electrical properties of the conductive hydrogels with layered structures prepared in Examples 3, 9, 10, and 11 were tested, and their initial resistance diagrams are shown below. Figure 6As shown, the corresponding strain resistance diagram is as follows: Figure 7 As shown, with the increase of the EGaIn micro / nanoparticle content ratio, the LM nanoparticle layer at the bottom thickens, thus forming a denser conductive network upon activation, thereby achieving lower resistance.

[0079] Test of the relative resistance change rate of a high-mechanical-performance conductive hydrogel with a layered structure under different operations

[0080] The relative change rate of resistance of the conductive hydrogel with a layered structure prepared in Example 10 was tested under different operations. The test results are as follows: Figure 8 , 9 As shown in Figure 10, the test results show that when weights of different masses (from 200g to 1000g) are placed on the layered conductive hydrogel, the relative resistance change is less than 0.75%. After 150 torsion cycles, the relative resistance change is less than 0.6%. Furthermore, the relative resistance change remains below 0.75% when subjected to bending tests at different angles. Therefore, this hydrogel exhibits high stability in maintaining conductivity under various deformation conditions.

[0081] Application Example 1

[0082] 1. Fabrication of ultrathin wearable capacitive sensors

[0083] Two layers of conductive hydrogel prepared in Example 10 were brought into contact with each other, so that the liquid metal conductive layers of the two hydrogels served as the upper and lower electrodes of the sensor, respectively. Then, they were encapsulated with VHB tape to prepare an ultrathin wearable capacitive sensor.

[0084] 2. Strain response testing of ultra-thin wearable capacitive sensors

[0085] The strain response of this ultra-thin wearable capacitive sensor to finger bending, knee bending, and swallowing modes was tested as follows: Figure 11 , 12 As shown in Figure 13, the results demonstrate that the ultrathin wearable capacitive sensor maintains a stable and sensitive response to different strains.

[0086] 3. Stress response test of ultra-thin wearable capacitive sensors

[0087] The response time of this ultra-thin wearable capacitive sensor under a single press was tested, and the results are as follows: Figure 14 As shown, the sensor responds quickly and is highly sensitive.

[0088] The response of this ultra-thin wearable capacitive sensor to repeated stress at different pressing times was tested, and the results are as follows: Figure 15As shown, the sensor maintains a stable and sensitive response under the same stress.

[0089] The response of this ultra-thin wearable capacitive sensor to repeated stress under different pressures was tested, and the results are as follows: Figure 16 As shown, the sensor maintains a stable and sensitive response under the same stress.

[0090] Application Example 2

[0091] 1. Preparation of bioelectrodes

[0092] The conductive hydrogel with a layered structure prepared in Example 10 can be used as a bioelectrode to measure electrooculography (EOG) signals by attaching it around the human eye and to measure electrocardiogram (ECG) signals by attaching it to the wrist pulse point. It exhibits high sensitivity and accuracy.

[0093] 2. EOG signal testing of bioelectrodes

[0094] The conductive hydrogel with a layered structure prepared in Example 10 was used as a bioelectrode for EOG signal testing, and the results are as follows: Figure 17 As shown, the different signal responses are displayed when looking to the left and to the right.

[0095] 3. ECG signal testing of bioelectrodes

[0096] The conductive hydrogel with a layered structure prepared in Example 10 was used as a bioelectrode for ECG signal testing, and the results are as follows: Figure 18 As shown, the different signal responses are displayed under normal conditions and after exercise.

Claims

1. A method for preparing a high-stretch high-conductivity hydrogel having a layered structure, characterized by, Specifically comprising the following steps: (1) according to the mass ratio of PEDOT:PSS solution to PVA is 1:1~3:1, first in the PVA solution is added to the mass concentration of 1.0% PEDOT:PSS solution, then add water and mix well to obtain monomer solution; (2) according to the mass ratio of EGaIn micro-nanoparticles to PVA is 0.5~1.5:1, EGaIn micro-nanoparticles are added to the monomer solution, and the mixed solution is obtained after ultrasonic dispersion; (3) the mixed solution is injected into the mold, heated and cured at 70±5℃ for 30~40min, then demolded, to obtain high-stretching and high-conducting hydrogel with layered structure.

2. The production method according to claim 1, characterized by, In step (1), the mass concentration of PVA solution is 10%, and the mass ratio of PEDOT:PSS solution to PVA is 2:

1.

3. The production method according to claim 1, characterized by, In step (1), the mass ratio of PVA and water in the monomer solution is 0.1:1.

494.

4. The high-stretching and high-conducting hydrogel with layered structure prepared by the preparation method of any one of claims 1-3.

5. The application of the high-stretching and high-conducting hydrogel with layered structure in claim 4 in the preparation of flexible wearable capacitive sensors.

6. Use according to claim 5, characterized in that, The specific method of application is: two pieces of the above-mentioned high-stretching and high-conducting hydrogel with layered structure are contacted with each other, and the conductive layers of the two pieces of hydrogel are respectively used as the upper and lower electrodes of the sensor, then packaged with VHB tape, to prepare a flexible wearable capacitive sensor.

7. The application of the high-stretching and high-conducting hydrogel with layered structure in claim 4 in the preparation of biological electrodes.

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