An extremely environment-stable fatigue fracture resistant self-adhesive ionic skin and a preparation method and application thereof

Abstract

The application discloses an extreme environment stable fatigue fracture self-adhesion ion skin and a preparation method and application thereof. The ion skin is formed by combination of chemically inert low cross-linked polydimethylsiloxane elastomer and perfluoroether rubber respectively with a stretchable ion conductive elastic fiber network through mechanical interlocking technology; wherein the polydimethylsiloxane elastomer is prepared by polymerization and curing of a silicone elastomer base and a PDMS curing agent, the perfluoroether rubber is obtained after solvent volatilization of a perfluoroether rubber solution, and the stretchable ion conductive elastic fiber network is obtained by electrospinning; the strength of the ion skin is greater than or equal to 9.9 MPa, the toughness is greater than or equal to 10 MJm ‑3 , the tensile strain is greater than or equal to 355%, the tensile toughness is greater than or equal to 5.7 MJm ‑3 , and the breaking energy is greater than or equal to 71.6 kJm ‑2 . The application of the ion skin in preparation of a flexible stretchable electronic device in an extreme environment. The application has simple process, excellent mechanical properties, extreme environment tolerance and self-adaptive surface adhesion capacity.

Description

Technical Field

[0001] The present invention belongs to the technical field of functional materials, and in particular relates to a fatigue-fracture-resistant self-adhesive ionic skin that is stable in extreme environments, and a preparation method and application thereof. Background Art

[0002] With the rapid development of the Internet of Things (IoT) and artificial intelligence (AI), flexible wearable electronic devices that mimic the responses of human skin to various environmental stimuli are gaining increasing attention. Inspired by natural biological systems, iontronics, an emerging interdisciplinary technology based on precise ion control, has greatly enriched the options for next-generation flexible electrode materials, shifting from traditional electronic conductors that require complex manufacturing processes or high costs to easily processable biomimetic ion conductors. Stretchable ion conductors, also known as ion skins, can be used as conformal sensors attached to human skin or the surface of soft robots due to their softness and stretchability to quantify and monitor movement and electrophysiological activities in real time. Among them, hydrogels are considered ideal ion conductors due to their inherent biocompatibility and ionic conductivity. However, the problem of hydrogels freezing or evaporating under extreme temperature conditions severely limits their effectiveness in long-term sensing applications. Therefore, additional sealing measures or the use of anti-dehydration chemicals are often required to address the problem of moisture adsorption / desorption.

[0003] Ionic liquid gels consist of a polymer network and an adsorbed ionic liquid. These gels are considered promising alternatives to hydrogels due to their unique properties of non-volatility, wide operating temperature range, and high ionic conductivity. However, these gels suffer from issues with ionic liquid loss and biocompatibility (Adv. Funct. Mater. 2023, 35, 2314408). Deep eutectic solvents (DES), an emerging alternative to ionic liquids, are formed through hydrogen bonding interactions and possess physicochemical properties similar to ionic liquids, such as high conductivity and low vapor pressure (Adv. Mater. 2023, 36, 2309576). However, DES-based deep eutectic gels are still inherently sensitive to humidity and temperature and cannot match the environmental tolerance of ionic liquid gels. In addition, the aforementioned stretchable ionic conductors are susceptible to contamination and damage by certain organic solvents. Overall, all current types of stretchable ionic conductors have not yet adapted to the extremely harsh environments that soft robots may encounter, including underwater, extreme high and low temperatures, vacuum, and corrosive environments.

[0004] In addition, although previous studies have made important progress in the basic mechanical properties of stretchable ion conductors, such as stretchability and flexibility, the soft chain network formed by solvent swelling or salt plasticization and its relatively uniform structural design have resulted in these ion conductors being mostly poor in mechanical strength and robustness. In particular, this defect limits their ability to effectively resist damage and seriously affects their service life (PNAS2024,16,e2322684121). In view of the defects that may occur during use and the reversible deformation that requires the material to have good durability, these ion conductors are also required to have excellent fatigue fracture resistance. The current existing technologies for ion conductors are as follows:

[0005] CN116246815A discloses an ion conductor with high transparency and conductivity, and its preparation method and application. The method directly mixes a crosslinking agent, an initiator, a monomer and an ionic liquid and obtains the ion conductor through a polymerization reaction.

[0006] CN116239852A discloses an ion conductor, its preparation method, and application. The preparation method for the ion conductor precursor solution comprises the following steps: mixing polyvinyl alcohol, phytic acid, and water; wherein the mass ratio of polyvinyl alcohol to phytic acid is less than 0.4. The preparation method for the ion conductor comprises the following steps: drying the ion conductor precursor solution at 20-120°C.

[0007] It can be seen from the above patented technology that although existing ion conductors have good ionic conductivity, excellent biocompatibility, high sensitivity, good energy storage performance and piezoresistive response capabilities, the preparation process is complex and the cost is high. Most importantly, the tolerance performance in extreme environments is still a defect, which significantly limits the application of ion conductors. Therefore, how to improve the mechanical properties (such as strain hardening, tear resistance and fatigue fracture resistance), environmental stability (high and low temperature resistance, waterproof and vacuum resistance) and adaptive surface adhesion of ion conductors based on their existing advantages, so that they can be used in extreme environments, has become a difficult problem that technical personnel in the field of functional materials urgently need to solve. Summary of the Invention

[0008] In view of the shortcomings of the existing technology, the technical problem to be solved by the present invention is to provide an extreme environment stable fatigue fracture resistant self-adhesive ionic skin with simple process, excellent mechanical properties, extreme environment tolerance and adaptive surface adhesion ability, and its preparation method and application.

[0009] To solve the above technical problems, the technical solution adopted by the present invention is: a fatigue-resistant and fracture-resistant self-adhesive ion skin that is stable in extreme environments, characterized in that: the ion skin is formed by combining a chemically inert low-crosslinked polydimethylsiloxane elastomer and perfluoroether rubber with a stretchable ion-conductive elastic fiber mesh through mechanical interlocking technology; wherein the polydimethylsiloxane elastomer is prepared by polymerization and curing of a silicone elastomer matrix and a PDMS curing agent, the perfluoroether rubber is obtained by evaporating the solvent of the perfluoroether rubber solution, and the stretchable ion-conductive elastic fiber mesh is obtained by electrostatic spinning, and the strength of the ion skin is ≥9.9MPa and the toughness is ≥10MJm -3 , tensile strain ≥355%, tensile toughness ≥5.7MJm -3 , fracture energy ≥71.6kJm -2 .

[0010] The above-mentioned extreme environment stable fatigue fracture resistant self-adhesive ionic skin, the mass ratio of the silicone elastomer matrix to the PDMS curing agent is 45:1-50:1; the loading concentration of the perfluoroether rubber solution is 0.8-1.2mLcm -2 The solvent evaporation conditions were set at 25°C for 10 minutes; the stretchable ion conductive elastic fiber mesh was prepared by electrospinning a spinning solution composed of a mixture of polyurethane particles, N,N-dimethylformamide, tetrahydrofuran and 1-ethyl-3-methylimidazole-bis(trifluoromethylsulfonyl)imide salt ionic liquid.

[0011] A method for preparing a fatigue-resistant and fracture-resistant self-adhesive ionic skin that is stable in extreme environments comprises the following steps:

[0012] 1. Preparation of ion conductive elastic fiber mesh:

[0013] (1) dissolving polyurethane particles in a mixture solution consisting of N,N-dimethylformamide and tetrahydrofuran, stirring at room temperature to obtain a uniform transparent polyurethane solution for standby use;

[0014] (2) adding 1-ethyl-3-methylimidazolium-bis(trifluoromethylsulfonyl)imide salt ionic liquid to the polyurethane solution and stirring uniformly to obtain a spinning solution;

[0015] (3) Using electrospinning technology, spinning under certain conditions to obtain a stretchable ion conductive elastic fiber mesh;

[0016] 2. Curing interlocking treatment:

[0017] (4) uniformly mixing the silicone elastomer matrix and the PDMS curing agent to prepare a PDMS prepolymer for later use;

[0018] (5) squeegeeing PDMS prepolymer onto oil paper, covering either side of the ion conductive elastic fiber mesh on the oil paper squeegeeed with PDMS prepolymer, and pre-curing the PDMS prepolymer so that it penetrates into the pores on one side of the ion conductive elastic fiber mesh by capillary action;

[0019] (6) Place the side of the prepolymer that has been infiltrated on oil paper coated with a certain thickness of PDMS prepolymer to form an adhesion layer on the surface of the PDMS prepolymer that has been infiltrated;

[0020] 3. Double-layer mechanical interlocking treatment:

[0021] (7) preparing a perfluoroether rubber solution of a certain concentration and injecting it into one side of the ion conductive elastic fiber mesh not filled with PDMS prepolymer to evaporate the solvent;

[0022] (8) The entire device is thermally cured in an oven to obtain a fatigue-resistant and fracture-resistant self-adhesive ionic skin that is stable in extreme environments.

[0023] The above-mentioned method for preparing the fatigue-resistant and fracture-resistant self-adhesive ionic skin that is stable in extreme environments, in the steps (1) and (2), the mass ratio of N,N-dimethylformamide and tetrahydrofuran is 1:1, the mass ratio of 1-ethyl-3-methylimidazolium-bis(trifluoromethylsulfonyl)imide salt ionic liquid to polyurethane particles is 1:1-1:4, and the mass percentage concentration of polyurethane in the spinning solution is 12-18wt%.

[0024] The above-mentioned method for preparing the fatigue-resistant and fracture-resistant self-adhesive ionic skin stable in extreme environments, in the step (3), the working voltage of the spinning equipment is 12-18 kV, and the spinning rate is 0.1-0.4 mL h -1 , the drum speed is 200-600rpm.

[0025] In the above-mentioned method for preparing the extreme environment stable fatigue fracture resistant self-adhesive ionic skin, in the step (4), the mass ratio of the silicone elastomer matrix to the PDMS curing agent is 45:1-50:1.

[0026] The above-mentioned method for preparing the fatigue-resistant and fracture-resistant self-adhesive ionic skin stable in extreme environments, in the step (5), the thickness of the PDMS prepolymer is 30-50 μm, the pre-curing temperature of the PDMS prepolymer is 80°C, and the pre-curing time is 130s.

[0027] In the above-mentioned method for preparing the extreme environment stable fatigue fracture resistant self-adhesive ionic skin, in the step (6), the thickness of the adhesive layer is 8-12 μm.

[0028] The above-mentioned method for preparing the fatigue-resistant and fracture-resistant self-adhesive ionic skin stable in extreme environments, in the step (7), the loading amount of the perfluoroether rubber is 0.8-1.2 mL / cm -2 The injection thickness of the perfluoroether rubber was 4.5 μm, and the solvent volatilization condition was set to 10 minutes at 25°C.

[0029] Application of ionic skin in the preparation of flexible and stretchable electronic devices for use in extreme environments.

[0030] The advantages of the present invention's extreme environment stable fatigue fracture resistant self-adhesive ion skin and its preparation method and application are: adopting a double-layer interlocking strategy, infiltrating a low-crosslinked PDMS precursor as the main matrix and adhesion layer into one side of the porous ion conductive elastic fiber network, and coating perfluoroether rubber as an encapsulation layer on the other side, and obtaining the final ultra-thin composite ion skin material after thermal curing. The preparation process of the present invention is simple and efficient, with low cost, and the prepared composite ion skin has the advantages of good mechanical properties (such as strain hardening, tear resistance and fatigue fracture resistance), excellent environmental stability (high and low temperature resistance, waterproof and vacuum resistance) and adaptive surface adhesion, etc., excellent mechanical properties, and can withstand extreme environmental conditions. The preparation process is simple and efficient, the preparation cost is low, and it is expected to be used in fields such as strain monitoring, temperature sensing and self-powered sensing, and has a relatively wide range of application value and development prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 Schematic diagram of the structure of the fatigue-fracture-resistant self-adhesive ionic skin of the present invention that is stable in extreme environments;

[0032] Figure 2 This is an SEM image of the ionic skin prepared in Example 2;

[0033] Figure 3 This is a scanning electron microscope photograph of the ion-conductive elastic fiber mesh obtained by electrospinning in Example 2;

[0034] Figure 4 SEM images of the pore structure of the surface layer of PDMS and ion-conductive elastic fiber mesh: (a) side view; (b) top view;

[0035] Figure 5 The stress-strain curves of the ion skin prepared in Example 2 with and without a notch;

[0036] Figure 6 This is a graph showing the relationship between the crack extension per cycle dc / dN of the ion skin prepared in Example 2 and the energy release rate of the composite ion skin;

[0037] Figure 7 Graphs showing adhesion test results of the ion skin prepared in Example 2 on various substrates in air and underwater;

[0038] Figure 8 This is a scanning electron microscope photograph of the ion skin prepared in Example 2 adhered to pig skin, showing a seamless adhesion interface between the composite ion skin and pig skin;

[0039] Figure 9 This is a graph showing the change in ionic skin environment tolerance data obtained in Example 2. Except for the high temperature test, the other ambient temperatures were controlled at 25° C., and the mass and ionic conductivity of the material were measured after maintaining each condition for 12 hours. DETAILED DESCRIPTION

[0040] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0041] In this disclosure, unless otherwise indicated, directional terms such as "upper" and "lower" generally refer to the upper and lower parts of a device in actual use or operation, specifically in the directions of the drawings in the accompanying drawings; whereas "inner" and "outer" refer to the outline of the device. Furthermore, in the description of this application, the term "including" means "including but not limited to." Terms such as first, second, and third are used merely as designations and do not impose numerical requirements or establish a sequence. The term "plurality" means "two or more."

[0042] like Figure 1-4 As shown, a fatigue-resistant and fracture-resistant self-adhesive ionic skin that is stable in extreme environments is formed by combining chemically inert, low-crosslinked polydimethylsiloxane elastomer and perfluoroether rubber with a stretchable ion-conductive elastic fiber mesh through mechanical interlocking technology. The polydimethylsiloxane elastomer is prepared by polymerization and curing of a silicone elastomer matrix and a PDMS curing agent, the perfluoroether rubber is obtained by evaporating the solvent of a perfluoroether rubber solution, and the stretchable ion-conductive elastic fiber mesh is obtained by electrospinning. The strength of the ionic skin is ≥9.9MPa and the toughness is ≥10MJm -3 , tensile strain ≥355%, tensile toughness ≥5.7MJm -3 , fracture energy ≥71.6kJm -2 .

[0043] A method for preparing a fatigue-resistant and fracture-resistant self-adhesive ionic skin that is stable in extreme environments comprises the following steps:

[0044] 1. Preparation of ion conductive elastic fiber mesh:

[0045] (1) dissolving polyurethane particles in a mixture solution consisting of N,N-dimethylformamide and tetrahydrofuran, stirring at room temperature to obtain a uniform transparent polyurethane solution for standby use;

[0046] (2) adding 1-ethyl-3-methylimidazolium-bis(trifluoromethylsulfonyl)imide salt ionic liquid to the polyurethane solution and stirring uniformly to obtain a spinning solution;

[0047] (3) Using electrospinning technology, spinning under certain conditions to obtain a stretchable ion conductive elastic fiber mesh;

[0048] 2. Curing interlocking treatment:

[0049] (4) uniformly mixing the silicone elastomer matrix and the PDMS curing agent to prepare a PDMS prepolymer for later use;

[0050] (5) squeegeeing PDMS prepolymer onto oil paper, covering either side of the ion conductive elastic fiber mesh on the oil paper squeegeeed with PDMS prepolymer, and pre-curing the PDMS prepolymer so that it penetrates into the pores on one side of the ion conductive elastic fiber mesh by capillary action;

[0051] (6) Place the side of the prepolymer that has been infiltrated on oil paper coated with a certain thickness of PDMS prepolymer to form an adhesion layer on the surface of the PDMS prepolymer that has been infiltrated;

[0052] 3. Double-layer mechanical interlocking treatment:

[0053] (7) preparing a perfluoroether rubber solution of a certain concentration and injecting it into one side of the ion conductive elastic fiber mesh not filled with PDMS prepolymer to evaporate the solvent;

[0054] (8) The entire device is thermally cured in an oven to obtain a fatigue-resistant and fracture-resistant self-adhesive ionic skin that is stable in extreme environments.

[0055] The ionic skin of the present invention can be used to prepare flexible and stretchable electronic devices under extreme environmental requirements, and has broad application value and development prospects in the fields of strain monitoring, temperature sensing and self-powered sensing.

[0056] Among them, polyurethane was purchased from Taiwan Risheng Company, item number BTE-75A; N,N-dimethylformamide was purchased from Sigma, item number 227056; tetrahydrofuran was purchased from Sigma, item number 401757; polydimethylsiloxane elastomer (PDMS prepolymer) was purchased from Dow Corning, USA, item number 184, composed of PDMS silicone elastomer matrix and PDMS curing agent; perfluoroether rubber was purchased from Shanghai Institute of Organic Chemistry, the product number is low-temperature resistant type; 1-ethyl-3-methylimidazole bis(trifluoromethylsulfonyl)imide salt was purchased from Aladdin Company, the product number is 174899-82-2; Performance Fluid was purchased from 3M Company, USA, PF-5060.

[0057] The present application will be described in detail below through specific examples. The following examples are only some examples of the present application and are not limitations of the present application.

[0058] Example 1:

[0059] The method for preparing the fatigue-resistant and fracture-resistant self-adhesive ionic skin of this embodiment comprises the following steps:

[0060] 1. Dissolve a certain amount of polyurethane particles in a mixture of N,N-dimethylformamide and tetrahydrofuran (1 / 1, wt / wt) and stir at room temperature for 24 hours to obtain a uniform, transparent polyurethane solution. Add 1-ethyl-3-methylimidazolium-bis(trifluoromethylsulfonyl)imide salt ionic liquid to the polyurethane solution at a 1:1 weight ratio and stir for 2 hours to obtain a spinning solution with a polyurethane concentration of 12 wt%.

[0061] 2. The spinning solution was spun at a voltage of 12 kV and a spinning rate of 0.1 mL / h. -1 , wrap aluminum foil on the drum, set the drum speed to 200 rpm, and the working distance from the needle to the collector to 11 cm to obtain an ion conductive elastic fiber mesh, such as Figure 3 shown.

[0062] 3. Prepare PDMS prepolymer by uniformly mixing the silicone elastomer matrix and PDMS curing agent at a mass ratio of 45:1. Apply a 30 μm thick layer of PDMS prepolymer solution onto oil-based paper using an AFA-II automatic film applicator. Cover either side of the ionically conductive elastic fiber mesh with a sticky PET frame for subsequent operation.

[0063] 4. Cover the other side of the ion conductive elastic fiber mesh directly on the oil paper coated with PDMS prepolymer and pre-cure it at 80℃ for 130s. The PDMS prepolymer will quickly penetrate into the pores of the ion conductive elastic fiber mesh through capillary action, and leave micropores on the upper surface to form an interlocking structure with the encapsulation layer, such as Figure 4 By controlling the pre-curing time of PDMS, it can completely penetrate into the fiber network except the upper surface.

[0064] 5. After pre-curing, place the side that has been infiltrated with PDMS prepolymer on oil paper coated with 8 μm thick PDMS prepolymer to form an adhesion layer.

[0065] 6. Dissolve 0.1g of perfluoroelastomer in 20g of 3M PF-5060 solvent as the encapsulation solution. Then, inject the perfluoroelastomer solution with Performance Fluid into the side not filled with PDMS, that is, into the adhesive PET frame, with a volume loading of 0.8mLcm-2 The perfluoroelastomer (PFEE) was 4.5 μm thick and formed a mechanical interlocking structure with the fiber network. It was then slowly dried at room temperature.

[0066] 7. The entire device was cured in an oven at 80°C for 2 hours to obtain the final double-layer mechanical interlocking composite ion skin, i.e., the extreme environment stable fatigue fracture resistant self-adhesive ion skin of the present invention, such as Figure 1 、 2 shown.

[0067] Example 2:

[0068] The method for preparing the fatigue-resistant and fracture-resistant self-adhesive ionic skin of this embodiment comprises the following steps:

[0069] 1. Dissolve a certain amount of polyurethane particles in a mixture of N,N-dimethylformamide and tetrahydrofuran (1 / 1, wt / wt) and stir at room temperature for 24 hours to obtain a uniform, transparent polyurethane solution. Add 1-ethyl-3-methylimidazolium-bis(trifluoromethylsulfonyl)imide salt ionic liquid to the polyurethane solution at a mass ratio of 1:2 and stir for 2 hours to obtain a spinning solution with a polyurethane concentration of 14 wt%.

[0070] 2. The spinning solution was spun at a voltage of 15.8 kV and a spinning rate of 0.2 mL h -1 , wrap aluminum foil on the drum, set the drum speed to 300 rpm, and the working distance from the needle to the collector to 11 cm to obtain an ion conductive elastic fiber mesh with a fiber diameter of about 1.27 μm, as shown Figure 3 shown.

[0071] 3. Prepare PDMS prepolymer by uniformly mixing the silicone elastomer matrix and PDMS curing agent at a mass ratio of 50:1. Apply a 40 μm thick layer of PDMS prepolymer solution onto oil-based paper using an AFA-II automatic film applicator. Cover either side of the ionically conductive elastic fiber mesh with a sticky PET frame for subsequent operation.

[0072] 4. Cover the other side of the ion conductive elastic fiber mesh directly on the oil paper coated with PDMS prepolymer and pre-cure it at 80℃ for 130s. The PDMS prepolymer will quickly penetrate into the pores of the ion conductive elastic fiber mesh through capillary action, and leave micropores on the upper surface to form an interlocking structure with the encapsulation layer, such as Figure 4 By controlling the pre-curing time of PDMS, it can completely penetrate into the fiber network except the upper surface.

[0073] 5. After pre-curing, place the side that has been infiltrated with PDMS prepolymer on oil paper coated with 10 μm thick PDMS prepolymer to form an adhesion layer.

[0074] 6. Dissolve 0.1g of perfluoroelastomer in 20g of 3M PF-5060 solvent as the encapsulation solution. Then, inject the perfluoroelastomer solution containing Performance Fluid into the adhesive PET frame on the side not filled with PDMS, with a volume loading of 1mLcm -2 The perfluoroelastomer (PFEE) was 4.5 μm thick and formed a mechanical interlocking structure with the fiber network. It was then slowly dried at room temperature.

[0075] 7. The entire device was cured in an oven at 80°C for 2 hours to obtain the final double-layer mechanical interlocking composite ion skin, i.e., the extreme environment stable fatigue fracture resistant self-adhesive ion skin of the present invention, such as Figure 1 、 2 shown.

[0076] Example 3:

[0077] The method for preparing the fatigue-resistant and fracture-resistant self-adhesive ionic skin of this embodiment comprises the following steps:

[0078] 1. Dissolve a certain amount of polyurethane particles in a mixture of N,N-dimethylformamide and tetrahydrofuran (1 / 1, wt / wt) and stir at room temperature for 24 hours to obtain a uniform, transparent polyurethane solution. Add 1-ethyl-3-methylimidazolium-bis(trifluoromethylsulfonyl)imide salt ionic liquid to the polyurethane solution at a mass ratio of 1:4 and stir for 2 hours to obtain a spinning solution with a polyurethane concentration of 14 wt%.

[0079] 2. The spinning solution was spun at a voltage of 13.9 kV and a spinning rate of 0.2 mL / h. -1 , wrap aluminum foil on the drum, set the drum speed to 300 rpm, and the working distance from the needle to the collector to 11 cm to obtain an ion conductive elastic fiber mesh, such as Figure 3 shown.

[0080] 3. Prepare PDMS prepolymer by uniformly mixing the silicone elastomer matrix and PDMS curing agent at a mass ratio of 46:1. Apply a 35 μm thick layer of PDMS prepolymer solution onto oil-based paper using an AFA-II automatic film applicator. Cover either side of the ionically conductive elastic fiber mesh with a sticky PET frame for subsequent operation.

[0081] 4. Cover the other side of the ion conductive elastic fiber mesh directly on the oil paper coated with PDMS prepolymer and pre-cure it at 80℃ for 130s. The PDMS prepolymer will quickly penetrate into the pores of the ion conductive elastic fiber mesh through capillary action, and leave micropores on the upper surface to form an interlocking structure with the encapsulation layer, such as Figure 4 By controlling the pre-curing time of PDMS, it can completely penetrate into the fiber network except the upper surface.

[0082] 5. After pre-curing, place the side that has been infiltrated with PDMS prepolymer on oil paper coated with 9 μm thick PDMS prepolymer to form an adhesion layer.

[0083] 6. Dissolve 0.1g of perfluoroelastomer in 20g of 3M PF-5060 solvent as the encapsulation solution. Then, inject the perfluoroelastomer solution with Performance Fluid into the side not filled with PDMS, that is, into the sticky PET frame, with a volume loading of 0.9mLcm -2 The perfluoroelastomer (PFEE) was 4.5 μm thick and formed a mechanical interlocking structure with the fiber network. It was then slowly dried at room temperature.

[0084] 7. The entire device was cured in an oven at 80°C for 2 hours to obtain the final double-layer mechanical interlocking composite ion skin, i.e., the extreme environment stable fatigue fracture resistant self-adhesive ion skin of the present invention, such as Figure 1 、 2 shown.

[0085] Example 4:

[0086] The method for preparing the fatigue-resistant and fracture-resistant self-adhesive ionic skin of this embodiment comprises the following steps:

[0087] 1. Dissolve a certain amount of polyurethane particles in a mixture of N,N-dimethylformamide and tetrahydrofuran (1 / 1, wt / wt) and stir at room temperature for 24 hours to obtain a uniform, transparent polyurethane solution. Add 1-ethyl-3-methylimidazolium-bis(trifluoromethylsulfonyl)imide salt ionic liquid to the polyurethane solution at a mass ratio of 1:3 and stir for 2 hours to obtain a spinning solution with a polyurethane concentration of 14 wt%.

[0088] 2. The spinning solution was spun at a voltage of 16.7 kV and a spinning rate of 0.3 mL / h. -1 , wrap aluminum foil on the drum, set the drum speed to 400 rpm, and the working distance from the needle to the collector to 11 cm to obtain an ion conductive elastic fiber mesh, such as Figure 3 shown.

[0089] 3. Prepare PDMS prepolymer by uniformly mixing the silicone elastomer matrix and PDMS curing agent at a mass ratio of 47:1. Apply a 40 μm thick layer of PDMS prepolymer solution onto oil-based paper using an AFA-II automatic film applicator using a scraper. Cover either side of the ionically conductive elastic fiber mesh with a sticky PET frame for subsequent operation.

[0090] 4. Cover the other side of the ion conductive elastic fiber mesh directly on the oil paper coated with PDMS prepolymer and pre-cure it at 80℃ for 130s. The PDMS prepolymer will quickly penetrate into the pores of the ion conductive elastic fiber mesh through capillary action, and leave micropores on the upper surface to form an interlocking structure with the encapsulation layer, such as Figure 4 By controlling the pre-curing time of PDMS, it can completely penetrate into the fiber network except the upper surface.

[0091] 5. After pre-curing, place the side that has been infiltrated with PDMS prepolymer on oil paper coated with 10 μm thick PDMS prepolymer to form an adhesion layer.

[0092] 6. Dissolve 0.1g of perfluoroelastomer in 20g of 3M PF-5060 solvent as the encapsulation solution. Then, inject the perfluoroelastomer solution containing Performance Fluid into the adhesive PET frame on the side not filled with PDMS, with a volume loading of 1mLcm -2 The perfluoroelastomer (PFEE) was 4.5 μm thick and formed a mechanical interlocking structure with the fiber network. It was then slowly dried at room temperature.

[0093] 7. The entire device was cured in an oven at 80°C for 2 hours to obtain the final double-layer mechanical interlocking composite ion skin, i.e., the extreme environment stable fatigue fracture resistant self-adhesive ion skin of the present invention, such as Figure 1 、 2 shown.

[0094] Example 5:

[0095] The method for preparing the fatigue-resistant and fracture-resistant self-adhesive ionic skin of this embodiment comprises the following steps:

[0096] 1. Dissolve a certain amount of polyurethane particles in a mixture of N,N-dimethylformamide and tetrahydrofuran (1 / 1, wt / wt) and stir at room temperature for 24 hours to obtain a uniform, transparent polyurethane solution. Add 1-ethyl-3-methylimidazolium-bis(trifluoromethylsulfonyl)imide salt ionic liquid to the polyurethane solution at a mass ratio of 1:2 and stir for 2 hours to obtain a spinning solution with a polyurethane concentration of 15 wt%.

[0097] 2. The spinning solution was spun at a voltage of 17.5 kV and a spinning rate of 0.4 mL / h. -1 , wrap aluminum foil on the drum, set the drum speed to 500 rpm, and the working distance from the needle to the collector to 11 cm to obtain an ion conductive elastic fiber mesh, such as Figure 3 shown.

[0098] 3. Prepare PDMS prepolymer by uniformly mixing the silicone elastomer matrix and PDMS curing agent at a mass ratio of 48:1. Apply a 45 μm thick layer of PDMS prepolymer solution onto oil-based paper using an AFA-II automatic film applicator. Cover either side of the ionically conductive elastic fiber mesh with a sticky PET frame for subsequent operation.

[0099] 4. Cover the other side of the ion conductive elastic fiber mesh directly on the oil paper coated with PDMS prepolymer and pre-cure it at 80℃ for 130s. The PDMS prepolymer will quickly penetrate into the pores of the ion conductive elastic fiber mesh through capillary action, and leave micropores on the upper surface to form an interlocking structure with the encapsulation layer, such as Figure 4 By controlling the pre-curing time of PDMS, it can completely penetrate into the fiber network except the upper surface.

[0100] 5. After pre-curing, place the side that has been infiltrated with PDMS prepolymer on oil paper coated with 11 μm thick PDMS prepolymer to form an adhesion layer.

[0101] 6. Dissolve 0.1g of perfluoroelastomer in 20g of 3M PF-5060 solvent as the encapsulation solution. Then, inject the perfluoroelastomer solution containing Performance Fluid into the adhesive PET frame on the side not filled with PDMS, with a volume loading of 1.1mLcm -2 The perfluoroelastomer (PFEE) was 4.5 μm thick and formed a mechanical interlocking structure with the fiber network. It was then slowly dried at room temperature.

[0102] 7. The entire device was cured in an oven at 80°C for 2 hours to obtain the final double-layer mechanical interlocking composite ion skin, i.e., the extreme environment stable fatigue fracture resistant self-adhesive ion skin of the present invention, such as Figure 1 、 2 shown.

[0103] Example 6:

[0104] The method for preparing the fatigue-resistant and fracture-resistant self-adhesive ionic skin of this embodiment comprises the following steps:

[0105] 1. Dissolve a certain amount of polyurethane particles in a mixture of N,N-dimethylformamide and tetrahydrofuran (1 / 1, wt / wt) and stir at room temperature for 24 hours to obtain a uniform, transparent polyurethane solution. Add 1-ethyl-3-methylimidazolium-bis(trifluoromethylsulfonyl)imide salt ionic liquid to the polyurethane solution at a mass ratio of 1:2 and stir for 2 hours to obtain a spinning solution with a polyurethane concentration of 18 wt%.

[0106] 2. The spinning solution was spun at a voltage of 18 kV and a spinning rate of 0.2 mL / h. -1 , wrap aluminum foil on the drum, set the drum speed to 600 rpm, and the working distance from the needle to the collector to 11 cm to obtain an ion conductive elastic fiber mesh, such as Figure 3 shown.

[0107] 3. Prepare PDMS prepolymer by uniformly mixing the silicone elastomer matrix and PDMS curing agent at a mass ratio of 49:1. Apply a 50 μm thick layer of PDMS prepolymer solution onto oil-based paper using an AFA-II automatic film applicator. Cover either side of the ionically conductive elastic fiber mesh with a sticky PET frame for subsequent operation.

[0108] 4. Cover the other side of the ion conductive elastic fiber mesh directly on the oil paper coated with PDMS prepolymer and pre-cure it at 80℃ for 130s. The PDMS prepolymer will quickly penetrate into the pores of the ion conductive elastic fiber mesh through capillary action, and leave micropores on the upper surface to form an interlocking structure with the encapsulation layer, such as Figure 4 By controlling the pre-curing time of PDMS, it can completely penetrate into the fiber network except the upper surface.

[0109] 5. After pre-curing, place the side that has been infiltrated with PDMS prepolymer on oil paper coated with 12 μm thick PDMS prepolymer to form an adhesion layer.

[0110] 6. Dissolve 0.1g of perfluoroelastomer in 20g of 3M PF-5060 solvent as the encapsulation solution. Then, inject the perfluoroelastomer solution containing Performance Fluid into the adhesive PET frame on the side not filled with PDMS, with a volume loading of 1.2mLcm -2 The perfluoroelastomer (PFEE) was 4.5 μm thick and formed a mechanical interlocking structure with the fiber network. It was then slowly dried at room temperature.

[0111] 7. The entire device was cured in an oven at 80°C for 2 hours to obtain the final double-layer mechanical interlocking composite ion skin, i.e., the extreme environment stable fatigue fracture resistant self-adhesive ion skin of the present invention, such as Figure 1 、2 shown.

[0112] The performance test results of the extreme environment stable fatigue fracture resistant self-adhesive ionic skin prepared in Example 2 of the present invention are as follows:

[0113] like Figure 1-4 As shown, two interlocking layers are formed on either side of an ionically conductive elastic fiber mesh 1: an interlocking layer 3 formed of polydimethylsiloxane elastomer 2 and an interlocking layer 5 formed of perfluoroelastomer 4. Interlocking layer 3 contains several dangling chains 6. The ionically conductive elastic fiber mesh 1 contains hard segments 1-1 and soft segments 1-2. The ionic liquid 8 possesses a number of positive and negative charges, which attach the hard segments 1-1 to the soft segments 1-2, further stabilizing the structure. SEM images of the material's cross-section reveal that the embedded ionic fiber network is uniformly distributed within the PDMS and perfluoroelastomer 7. This interlocking structure not only contributes to structural stability but also facilitates stress transfer during deformation. The rearrangement of the randomly oriented fiber network within the matrix imparts mechanical properties similar to those of human skin. The mechanical properties of the material were characterized using a universal testing machine. The composite ion skin exhibits a characteristic "J-shaped" stress-strain curve, closely resembling the strain hardening characteristics of human skin: large deformation occurs at low stress, the modulus gradually increases with increasing strain, and ultimately, the stress increases almost linearly before failure. In summary, from the perspective of mechanical biomimetic, the low initial modulus of ionic skin (0.9 MPa) is close to that of human skin (0.42-3.7 MPa), and the strain (250%) without obvious hardening during stretching is much higher than the natural deformation of human skin (<80%), all of which ensure good matching with skin. At the same time, the high strength (9.9 MPa) and high toughness (10 MJ m -3 ) can protect against tensile damage.

[0114] like Figure 5 As shown in Figure 2, for the notched ion skin, the final stress-strain curve still shows the effect of strain hardening. The tensile strain, tensile toughness and fracture energy of the notched composite ion skin are as high as ~355%, 5.7 MJm -3 and 71.6 kJ m -2 Next, a cyclic loading-unloading test was performed to characterize the sample's resistance to fatigue fracture. The composite ion skin can withstand 50,000 cycles at 300% strain, which clearly demonstrates the important role played by the ion fiber mesh in improving the material's resistance to fatigue fracture. In addition, by recording the crack propagation during stretching, it was calculated that the fatigue threshold of the composite ion skin reached the highest value of stretchable materials, ~12.4 kJ m -2 .

[0115] like Figure 6As shown in the figure, adhesion is crucial for sensors applied to the continuously deforming curved surface of the skin, because they always produce high-quality signals due to the conformal contact with the skin. The low cross-linking degree of PDMS not only makes the composite ionic skin have good adhesion to the surface of various materials, but also effectively avoids the leakage problem of ionic liquid, making the ionic skin have good biocompatibility. According to the SEM of the composite ionic skin adhesion to pig skin, a mechanical interlocking structure with no gap residue can be seen at the formed interface, indicating that the composite ionic skin has good interface-adaptive adhesion ability. In addition, as Figure 7 As shown in Figure 2, the 90° peel test was used to quantitatively measure the adhesion strength of the material to various substrates. Figure 7-9 As shown, except for pigskin and wood with strong water absorption, the adhesion strength of the composite ion skin to these substrates is almost unaffected by moisture, indicating that it can be directly and stably applied to the surfaces of these materials without the aid of other adhesive tapes.

[0116] To further evaluate the material's environmental stability, the composite ion skin was treated with varying humidity, saline solutions, vacuum, and high temperatures to investigate changes in its properties. Because the ion fiber network is tightly embedded in the inherently inert PDMS and perfluoroelastomer, and the ionic liquid within the ion fibers is difficult to evaporate, the composite ion skin's weight, ionic conductivity, and mechanical properties are stable under various environmental conditions. It is also resistant to high and low temperatures, water, and vacuum, demonstrating potential for long-term applications.

[0117] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Any changes, modifications, additions or substitutions made by ordinary technicians in this technical field within the essential scope of the present invention should fall within the scope of protection of the present invention.

Claims

1. A self-adhesive ionic skin that is stable in extreme environments and resistant to fatigue fracture, characterized by: The ion skin is formed by combining chemically inert low-crosslinked polydimethylsiloxane elastomer and perfluoroether rubber with a stretchable ion-conductive elastic fiber mesh through mechanical interlocking technology. The polydimethylsiloxane elastomer is prepared by polymerization and curing of a silicone elastomer matrix and a PDMS curing agent, the perfluoroether rubber is obtained by evaporating the solvent of a perfluoroether rubber solution, and the stretchable ion-conductive elastic fiber mesh is obtained by electrostatic spinning. The strength of the ion skin is ≥9.9MPa and the toughness is ≥10MJ·m -3 , tensile strain ≥355%, tensile toughness ≥5.7MJ·m -3 , fracture energy ≥71.6kJ·m -2 .

2. The extreme environment stable fatigue fracture resistant self-adhesive ionic skin according to claim 1, characterized in that: The mass ratio of the silicone elastomer matrix to the PDMS curing agent is 45:1-50:1; the loading amount of the perfluoroether rubber solution is 0.8-1.2 mL·cm -2 The solvent evaporation conditions were set at 25°C for 10 minutes; the stretchable ion conductive elastic fiber mesh was prepared by electrospinning a spinning solution composed of a mixture of polyurethane particles, N,N-dimethylformamide, tetrahydrofuran and 1-ethyl-3-methylimidazole-bis(trifluoromethylsulfonyl)imide salt ionic liquid.

3. A method for preparing the extreme environment stable fatigue fracture resistant self-adhesive ionic skin according to any one of claims 1-2, characterized in that: The steps include:

1. Preparation of ion conductive elastic fiber mesh: (1) Dissolve the polyurethane particles in a mixture solution consisting of N,N-dimethylformamide and tetrahydrofuran, stir at room temperature to obtain a uniform transparent polyurethane solution for later use; (2) adding 1-ethyl-3-methylimidazole-bis(trifluoromethylsulfonyl)imide salt ionic liquid to the polyurethane solution and stirring evenly to obtain a spinning solution; (3) Using electrospinning technology, spinning is performed under certain conditions to obtain a stretchable ion conductive elastic fiber mesh; 2. Curing interlocking treatment: (4) Evenly mix the silicone elastomer matrix and the PDMS curing agent to prepare a PDMS prepolymer for later use; (5) Scrape the PDMS prepolymer onto oil paper, cover any side of the ion conductive elastic fiber mesh on the oil paper with the PDMS prepolymer, and perform pre-curing. The PDMS prepolymer penetrates into the pores on one side of the ion conductive elastic fiber mesh through capillary action; (6) Place the side of the prepolymer that has been infiltrated on oil paper coated with a certain thickness of PDMS prepolymer to form an adhesion layer on the surface of the PDMS prepolymer that has been infiltrated; 3. Double-layer mechanical interlocking treatment: (7) Prepare a perfluoroether rubber solution of a certain concentration and inject it into one side of the ion conductive elastic fiber mesh that is not filled with PDMS prepolymer to evaporate the solvent; (8) The entire device is thermally cured in an oven to obtain a fatigue-resistant and fracture-resistant self-adhesive ionic skin that is stable in extreme environments.

4. The method for preparing the extreme environment stable fatigue fracture resistant self-adhesive ionic skin according to claim 3, characterized in that: In the steps (1) and (2), the mass ratio of N,N-dimethylformamide to tetrahydrofuran is 1:1, the mass ratio of 1-ethyl-3-methylimidazole-bis(trifluoromethylsulfonyl)imide salt ionic liquid to polyurethane particles is 1:1-1:4, and the mass percentage concentration of polyurethane in the spinning solution is 12-18 wt%.

5. The method for preparing the extreme environment stable fatigue fracture resistant self-adhesive ionic skin according to claim 3, characterized in that: In step (3), the operating voltage of the spinning equipment is 12-18 kV, and the spinning rate is 0.1-0.4 mL·h -1 , the drum speed is 200-600rpm.

6. The method for preparing the extreme environment stable fatigue fracture resistant self-adhesive ionic skin according to claim 3, characterized in that: In the step (4), the mass ratio of the silicone elastomer matrix to the PDMS curing agent is 45:1-50:

1.

7. The method for preparing the extreme environment stable fatigue fracture resistant self-adhesive ionic skin according to claim 3, characterized in that: In the step (5), the thickness of the PDMS prepolymer applied by scraping is 30-50 μm, the pre-curing temperature of the PDMS prepolymer is 80° C., and the pre-curing time is 130 s.

8. The method for preparing the extreme environment stable fatigue fracture resistant self-adhesive ionic skin according to claim 3, characterized in that: In the step (6), the thickness of the adhesion layer is 8-12 μm.

9. The method for preparing the extreme environment stable fatigue fracture resistant self-adhesive ionic skin according to claim 3, characterized in that: In step (7), the loading amount of perfluoroether rubber is 0.8-1.2 mL·cm -2 The injection thickness of the perfluoroether rubber was 4.5 μm, and the solvent volatilization condition was set to 10 minutes at 25°C.

10. Use of the ionic skin according to any one of claims 1 to 2 in preparing flexible and stretchable electronic devices for use in extreme environments.

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