Self-repairing photothermal graphene passive pressure-induced thermoelectric skin material and preparation method

Abstract

The application relates to the technical field of high polymer materials, and discloses a self-repairing photothermal graphene passive pressure thermoelectronic skin material and a preparation method. The preparation of the passive pressure thermoelectronic skin material comprises the following steps: step 1: mixing ureido pyrimidone modified PDMS and MXene to obtain a high polymer composition; step 2: coating the high polymer composition into a film to form a base layer; sequentially laminating the base layer with a piezoelectric-frictional electric layer, a photothermal layer and an encapsulation layer, and using a silicon-oxygen coupling agent solution to perform bonding on the contact interface; and heat pressing and curing to obtain the passive pressure thermoelectronic skin material; in the raw materials of the high polymer composition, 5-15 wt% of MXene and the rest of ureido pyrimidone modified PDMS are used according to mass percentage. In the application, the prepared passive pressure thermoelectronic skin material has the advantages of high photothermal efficiency, good self-repairing performance, wide application scenarios and the like.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, specifically to a self-healing photothermal graphene passive pressure-heated electronic skin material and its preparation method. Background Technology

[0002] Passive pressure-thermal electronic skin materials, possessing energy autonomy and pressure-thermal synergy, have become a core research direction in fields such as medicine and robotics. While existing self-healing electronic skin technologies have solved the durability problem, they still suffer from the following drawbacks: First, the materials exhibit poor photothermal performance; under static pressure, the energy conversion efficiency of current self-healing materials is generally below 15%, unable to support the precise heating requirements of 38-42℃. Second, the materials have poor self-healing properties, often resulting in wrinkles and damage in application scenarios, and a decline in photothermal performance and performance retention rate after repeated use; leading to usage limitations, reduced lifespan, and decreased user experience. Third, their application scenarios are limited, making them unsuitable for diverse applications. Therefore, addressing these issues and providing a self-healing photothermal graphene passive pressure-thermal electronic skin material is of great significance. Summary of the Invention

[0003] The purpose of this invention is to provide a self-healing photothermal graphene passive pressure-thermal electronic skin material and its preparation method, so as to solve the problems mentioned in the background art.

[0004] To solve the above-mentioned technical problems, the present invention provides the following technical solution: The preparation method of self-healing photothermal graphene passive pressure-heated electronic skin material includes the following steps: Step 1: Mix uracil-modified PDMS and MXene to obtain a polymer composition; Step 2: Coat the polymer composition into a film to form a base layer; then stack it sequentially with the piezoelectric-triboelectric layer, photothermal layer, and encapsulation layer, and bond the contact interfaces using a silicone coupling agent solution; hot-press and cure to obtain a passive pressure-heated electronic skin material; The raw materials of the polymer composition contain, by mass percentage: 5-15 wt% MXene, and the remainder is uracil-modified PDMS.

[0005] In a more optimized manner, the preparation method of the uracil-modified PDMS is as follows: (1) Take 2-amino-4-hydroxy-6-methylpyrimidine and hexamethylene diisocyanate, heat to 95~100℃ under nitrogen protection and react, then treat to obtain Upy-NCO; (2) Mix the hydroxyl-terminated PDMS prepolymer and Upy-NCO, add dibutyltin dilaurate, stir and react to obtain modified PDMS.

[0006] In a more optimized manner, the mass ratio of 2-amino-4-hydroxy-6-methylpyrimidine to hexamethylene diisocyanate in the raw materials of Upy-NCO is (0.5~1):(5~10). In the raw materials of the modified PDMS, the mass ratio of PDMS prepolymer to Upy-NCO is (8~10):1, and the amount of dibutyltin dilaurate added is 0.3~0.5wt% of the total mass of PDMS prepolymer and Upy-NCO.

[0007] Ideally, the silica-oxygen coupling agent solution is composed of a silane coupling agent and anhydrous ethanol in a mass ratio of 1:(8~10); the spraying amount of the silica-oxygen coupling agent solution at the contact interface is 0.1~0.2 mL / cm. 2 .

[0008] The silicone coupling agent solution serves as the adhesive at the contact interface. When spraying the silicone coupling agent solution, the environment must be kept dry (humidity ≤60%) to avoid moisture affecting the bonding effect. Each layer must be bonded within 30 minutes after the adhesive is sprayed to prevent the active groups from becoming ineffective.

[0009] In a more optimized manner, the raw material of the piezoelectric-triboelectric layer comprises 5-12 wt% MXene, with the remainder being polymer materials; the raw material of the photothermal layer comprises 5-12 wt% thermal filler, with the remainder being polymer materials; the encapsulation layer includes one of polyimide film and polytetrafluoroethylene film; the polymer materials include one or two of PDMS and polycaprolactone; and the thermal filler includes one or two of graphene and CsPbBr3 quantum dots.

[0010] In a more optimized manner, the raw materials of the polymer composition used in the substrate layer further include a modifier, wherein the raw materials of the polymer composition, by mass percentage, are: 5-15 wt% MXene, 3-9 wt% modifier, 0.06-0.18 wt% photoinitiator, and the remainder is uracil-modified PDMS; The modifier comprises iron oxide / graphene, polycaprolactone, polyethylene glycol thioglycolate, and branched polysiloxane in a mass ratio of (0.5~1.5):(1.5~4.5):(1~3).

[0011] In a more optimized manner, the preparation method of the branched polysiloxane is as follows: (1) Tetramethyltetravinylcyclotetrasiloxane and catalyst are added to methanol; under an inert gas atmosphere, the temperature is raised to 50~55℃; a trimethoxyhydrosilane-methanol mixture is added, the reaction is carried out for 8~12h, and the reaction is post-treated to obtain a silane containing double bonds; (2) The silane containing double bonds and acetic anhydride are mixed, tetra(trimethylsiloxy)titanium is added, the temperature is raised to 60~65℃, and the temperature is kept under vacuum for 10~15h to obtain a branched polysiloxane.

[0012] More preferably, the silane containing double bonds comprises the following raw materials, by mass parts: 40-50 parts tetramethyltetravinylcyclotetrasiloxane, 0.1-0.15 parts catalyst, and 30-40 parts trimethoxyhydrosilane; the branched polysiloxane comprises the following raw materials, by mass parts: 5-6 parts silane containing double bonds, 0.8-1.2 parts acetic anhydride, and 0.1-0.2 parts tetra(trimethylsiloxy)titanium.

[0013] The preparation method of the iron oxide / graphene is optimized as follows: (1) Nano-iron oxide is modified with an aminosilane coupling agent to obtain amino iron oxide; (2) Graphene oxide and NHS-EDC are dispersed in water, amino iron oxide and hydrazine hydrate are added, the temperature is raised to 80~85℃, and the mixture is stirred at a constant temperature for 1~2 hours. The mixture is then washed and dried to obtain iron oxide / graphene. The mass ratio of graphene oxide to amino iron oxide is 1:(0.5~0.6).

[0014] In a more optimized manner, the passive pressure-heated electronic skin material prepared by the method for preparing the self-healing photothermal graphene passive pressure-heated electronic skin material comprises, in sequence, a substrate layer, a piezoelectric-triboelectric layer, a photothermal layer, and an encapsulation layer; the thickness of the substrate layer is 50~60μm, the thickness of the piezoelectric-triboelectric layer is 20~40μm, the thickness of the photothermal layer is 15~40μm, and the thickness of the encapsulation layer is 8~15μm.

[0015] Compared with existing technologies, the beneficial effects achieved by this invention are as follows: First, by setting MXene, graphene, and other fillers in the multilayer structure, this application effectively forms a photothermal interconnection network, reducing photothermal interruption in the passive pressure-heated electronic skin material, thereby effectively promoting energy conversion efficiency to over 35% and improving thermal performance. Simultaneously, the multilayer silane coupling agent solution coating-hot pressing molding process is compatible with roll-to-roll mass production equipment, resulting in high production efficiency and low manufacturing cost.

[0016] Secondly, in order to improve the wrinkles and damage that occur after repeated use, this application limits the composition of the base layer, using uracil-modified PDMS as the main body, utilizing the dynamic quadruple hydrogen bonds of uracil-modified PDMS to effectively ensure self-healing properties, and introducing 5~15wt% MXene as a basic filler to ensure basic photothermal performance.

[0017] In a further refinement, a composite of iron oxide / graphene, polycaprolactone-polyethylene glycol thiol, and branched polysiloxane is introduced as a modifier for the substrate layer to further improve performance. The introduction of iron oxide / graphene allows for the creation of a highly efficient thermally conductive network through the synergy between iron oxide nanoparticles and graphene. The iron oxide nanoparticles loaded onto graphene reduce interfacial thermal resistance and, in conjunction with MXene, rapidly and uniformly diffuse heat throughout the substrate layer. This avoids localized overheating near the MXene sheets, improving the overall photothermal response speed and uniformity. Simultaneously, iron oxide also exhibits photothermal effects, while graphene absorbs visible / near-infrared light (wavelengths 400-1000 nm) and converts it into heat energy, assisting the Joule heating effect to enhance static heating power. Therefore, iron oxide / graphene can complement MXene in light absorption. Furthermore, the uniformity of the thermally conductive network promotes molecular chain motion and hydrogen bond reconstruction, thereby facilitating self-repair.

[0018] The incorporated polycaprolactone-polyethylene glycol thiol groups can promote filler dispersion and prevent agglomeration. Furthermore, with the introduction of a photoinitiator, they can undergo moderate crosslinking with branched polysiloxanes, improving the flexibility of the substrate layer, promoting stress distribution during deformation, and inhibiting the formation of initial cracks and wrinkles. This, in conjunction with the self-healing properties of uracil-modified PDMS, inhibits the formation of micro-damage and permanent wrinkles after deformation, ensuring the maintenance of photothermal efficiency and improving service life.

[0019] Third, the passive pressure-heated electronic skin material prepared in this application is suitable for a variety of application scenarios, such as continuous medical hyperthermia, static gripping of humanoid robots, press-heated toys, cushions and other scenarios suitable for pressure-heated heating and warmth preservation. Attached Figure Description

[0020] Figure 1 This is a product diagram of Embodiment 1 of the present invention. Detailed Implementation

[0021] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] In the following embodiments, the parts are by weight; it should be noted that there are no special restrictions on the manufacturers of the raw materials involved in this invention, and they include, exemplarily, PDMS prepolymer (hydroxyl-terminated, PB37003), MXene (Ti3C2T) xMXene, graphene (XH-C-3), CsPbBr3 quantum dots (Qiyue Biotechnology), catalysts (Karstedt catalysts); photoinitiators (TPO); polycaprolactone polyethylene glycol mercapto (Tanshtech); nano-iron oxide (30nm); aminosilane coupling agent (KH550); graphene oxide (XH-C-2); NHS (N-hydroxysuccinimide); EDC (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide); acrylate-based polyethylene glycol polycaprolactone (Boquan).

[0023] Example 1: Pre-preparation: 0.7 parts of 2-amino-4-hydroxy-6-methylpyrimidine and 7 parts of hexamethylene diisocyanate were taken and reacted at 100°C for 16 h under nitrogen protection. The mixture was washed with n-hexane and dried to obtain Upy-NCO. PDMS prepolymer and Upy-NCO were mixed at a mass ratio of 10:1. Dibutyltin dilaurate was added at a mass ratio of 0.5 wt% of the total mass of PDMS prepolymer and Upy-NCO. The mixture was stirred at 60°C for 2 h to obtain uracil-modified PDMS. KH-550 was mixed with anhydrous ethanol at a mass ratio of 1:10, stirred evenly, and allowed to stand for 10 minutes to obtain a silicon-oxygen coupling agent solution, which was used as a binder. S1: 10wt% of MXene with a particle size of 50~100nm and 90wt% of uracil-modified PDMS were ultrasonically mixed for 30min, coated into a film, and dried at 80℃ for 1h to obtain a substrate layer with a thickness of 55μm. 10 wt% of MXene with a particle size of 50~100 nm was ultrasonically mixed with 90 wt% of uracil-modified PDMS for 30 min, coated into a film, and dried at 75 °C for 40 min to obtain a piezoelectric-triboelectric layer with a thickness of 40 μm. 25 wt% graphene and 75 wt% uracil-modified PDMS were ultrasonically mixed for 30 min, coated into a film, and dried at 70 °C for 30 min to obtain a photothermal layer with a thickness of 35 μm. S2: Spray adhesive onto the substrate surface at a rate of 0.15 mL / cm², attach the piezoelectric-triboelectric layer to the side with the adhesive, spray adhesive onto the piezoelectric-triboelectric layer surface at a rate of 0.15 mL / cm², attach the photothermal layer to the side with the adhesive, spray adhesive onto the photothermal layer surface at a rate of 0.15 mL / cm², attach a 12 μm polyimide film to the side with the adhesive, and hot-press and cure at 100℃ and 0.3 MPa for 5 min to obtain a passive pressure-heated electronic skin material.

[0024] Example 2: Pre-preparation: 0.7 parts of 2-amino-4-hydroxy-6-methylpyrimidine and 7 parts of hexamethylene diisocyanate were taken and reacted at 100°C for 16 h under nitrogen protection. The mixture was washed with n-hexane and dried to obtain Upy-NCO. PDMS prepolymer and Upy-NCO were mixed at a mass ratio of 8:1. Dibutyltin dilaurate was added at a mass ratio of 0.5 wt% of the total mass of PDMS prepolymer and Upy-NCO. The mixture was stirred at 60°C for 2 h to obtain uracil-modified PDMS. KH-550 was mixed with anhydrous ethanol at a mass ratio of 1:10, stirred evenly, and allowed to stand for 10 minutes to obtain a silicon-oxygen coupling agent solution, which was used as a binder. S1: 15wt% of MXene with a particle size of 50~100nm and 85wt% of uracil-modified PDMS were ultrasonically mixed for 30min, coated into a film, and dried at 80℃ for 1h to obtain a substrate layer with a thickness of 55μm. 12 wt% of MXene with a particle size of 50-100 nm was ultrasonically mixed with 88 wt% of uracil-modified PDMS for 30 min, coated into a film, and dried at 75 °C for 40 min to obtain a piezoelectric-triboelectric layer with a thickness of 40 μm. 30 wt% graphene and 70 wt% uracil-modified PDMS were ultrasonically mixed for 30 min, coated into a film, and dried at 70 °C for 30 min to obtain a photothermal layer with a thickness of 35 μm. S2: Spray adhesive onto the substrate surface at a rate of 0.15 mL / cm², attach the piezoelectric-triboelectric layer to the side with the adhesive, spray adhesive onto the piezoelectric-triboelectric layer surface at a rate of 0.15 mL / cm², attach the photothermal layer to the side with the adhesive, spray adhesive onto the photothermal layer surface at a rate of 0.15 mL / cm², attach a 12 μm polyimide film to the side with the adhesive, and hot-press and cure at 100℃ and 0.3 MPa for 5 min to obtain a passive pressure-heated electronic skin material.

[0025] Example 3: Pre-preparation: 0.7 parts of 2-amino-4-hydroxy-6-methylpyrimidine and 7 parts of hexamethylene diisocyanate were taken and reacted at 100°C for 16 h under nitrogen protection. The mixture was washed with n-hexane and dried to obtain Upy-NCO. PDMS prepolymer and Upy-NCO were mixed at a mass ratio of 8:1. Dibutyltin dilaurate was added at a mass ratio of 0.5 wt% of the total mass of PDMS prepolymer and Upy-NCO. The mixture was stirred at 60°C for 2 h to obtain uracil-modified PDMS. KH-550 was mixed with anhydrous ethanol at a mass ratio of 1:10, stirred evenly, and allowed to stand for 10 minutes to obtain a silicon-oxygen coupling agent solution, which was used as a binder. Preparation of iron oxide / graphene: 10 parts of nano-Fe3O4 were dispersed in 80 parts of isopropanol and 10 parts of water, and 1 part of aminosilane coupling agent was added. Under nitrogen protection, the mixture was heated to 70℃ and stirred for 4 hours. After washing and drying, amino-iron oxide was obtained. 1 part of graphene oxide, 0.2 parts of NHS and 0.3 parts of EDC were dispersed in 150 parts of water, and 0.5 parts of amino-iron oxide and 0.1 parts of hydrazine hydrate were added. The mixture was heated to 85℃ and stirred for 2 hours. After washing and drying, iron oxide / graphene was obtained. Preparation of branched polysiloxane: The branched polysiloxane is prepared as follows: 45 parts of tetramethyltetravinylcyclotetrasiloxane and 0.15 parts of catalyst are added to 20 parts of methanol; the temperature is raised to 55°C under nitrogen protection, and a mixture of 35 parts of trimethoxyhydrosilane and 20 parts of methanol is added. The mixture is kept at this temperature for 8 hours, 3 parts of activated carbon are added, and the mixture is stirred for another 0.5 hours. The liquid is filtered and rotated at 38°C for 1 hour to obtain a silane monomer containing double bonds; 5 parts of the silane containing double bonds and 1 part of acetic anhydride are mixed, and 0.1 parts of tetra(trimethylsiloxy)titanium are added. The mixture is heated to 65°C and kept under vacuum for 12 hours to obtain the branched polysiloxane. S1: 15wt% of MXene with a particle size of 50~100nm, 8wt% of modifier, 0.1wt% of photoinitiator, and 76.9wt% of uracil-modified PDMS were ultrasonically mixed for 30min, coated into a film, irradiated with ultraviolet light at a wavelength of 365nm for 30s, and dried at 80℃ for 1h to obtain a base layer with a thickness of 55μm. The modifier is iron oxide / graphene, polycaprolactone, polyethylene glycol thioglycolate, and branched polysiloxane in a mass ratio of 1:3:2. 12 wt% of MXene with a particle size of 50-100 nm was ultrasonically mixed with 88 wt% of uracil-modified PDMS for 30 min, coated into a film, and dried at 75 °C for 40 min to obtain a piezoelectric-triboelectric layer with a thickness of 40 μm. 30 wt% graphene and 70 wt% uracil-modified PDMS were ultrasonically mixed for 30 min, coated into a film, and dried at 70 °C for 30 min to obtain a photothermal layer with a thickness of 35 μm. S2: Spray adhesive onto the substrate surface at a rate of 0.15 mL / cm², attach the piezoelectric-triboelectric layer to the side with the adhesive, spray adhesive onto the piezoelectric-triboelectric layer surface at a rate of 0.15 mL / cm², attach the photothermal layer to the side with the adhesive, spray adhesive onto the photothermal layer surface at a rate of 0.15 mL / cm², attach a 12 μm polyimide film to the side with the adhesive, and hot-press and cure at 100℃ and 0.3 MPa for 5 min to obtain a passive pressure-heated electronic skin material.

[0026] Comparative Example 1 (with increased modifier dosage, otherwise the same as Example 3): S1: 15wt% of MXene with a particle size of 50~100nm, 10wt% of modifier, 0.1wt% of photoinitiator, and 76.9wt% of uracil-modified PDMS were ultrasonically mixed for 30min, coated into a film, and dried at 80℃ for 1h to obtain a base layer with a thickness of 55μm; The modifier is iron oxide / graphene, polycaprolactone, polyethylene glycol thioglycolate, and branched polysiloxane in a mass ratio of 1:3:2. 12 wt% of MXene with a particle size of 50-100 nm was ultrasonically mixed with 88 wt% of uracil-modified PDMS for 30 min, coated into a film, and dried at 75 °C for 40 min to obtain a piezoelectric-triboelectric layer with a thickness of 40 μm. 30 wt% graphene and 70 wt% uracil-modified PDMS were ultrasonically mixed for 30 min, coated into a film, and dried at 70 °C for 30 min to obtain a photothermal layer with a thickness of 35 μm. S2: Spray adhesive onto the substrate surface at a rate of 0.15 mL / cm², attach the piezoelectric-triboelectric layer to the side with the adhesive, spray adhesive onto the piezoelectric-triboelectric layer surface at a rate of 0.15 mL / cm², attach the photothermal layer to the side with the adhesive, spray adhesive onto the photothermal layer surface at a rate of 0.15 mL / cm², attach a 12 μm polyimide film to the side with the adhesive, and hot-press and cure at 100℃ and 0.3 MPa for 5 min to obtain a passive pressure-heated electronic skin material.

[0027] Comparative Example 2 (MXene is used instead of iron oxide / graphene, and the rest is the same as in Example 3): S1: 15wt% of MXene with a particle size of 50~100nm, 8wt% of modifier, 0.1wt% of photoinitiator, and 76.9wt% of uracil-modified PDMS are ultrasonically mixed for 30min, coated into a film, and dried at 80℃ for 1h to obtain a substrate layer with a thickness of 55μm. The modifier is MXene, polycaprolactone polyethylene glycol mercapto and branched polysiloxane in a mass ratio of 1:3:2; 12 wt% of MXene with a particle size of 50-100 nm was ultrasonically mixed with 88 wt% of uracil-modified PDMS for 30 min, coated into a film, and dried at 75 °C for 40 min to obtain a piezoelectric-triboelectric layer with a thickness of 40 μm. 30 wt% graphene and 70 wt% uracil-modified PDMS were ultrasonically mixed for 30 min, coated into a film, and dried at 70 °C for 30 min to obtain a photothermal layer with a thickness of 35 μm. S2: Spray adhesive onto the substrate surface at a rate of 0.15 mL / cm², attach the piezoelectric-triboelectric layer to the side with the adhesive, spray adhesive onto the piezoelectric-triboelectric layer surface at a rate of 0.15 mL / cm², attach the photothermal layer to the side with the adhesive, spray adhesive onto the photothermal layer surface at a rate of 0.15 mL / cm², attach a 12 μm polyimide film to the side with the adhesive, and hot-press and cure at 100℃ and 0.3 MPa for 5 min to obtain a passive pressure-heated electronic skin material.

[0028] Comparative Example 3 (adjust the addition ratio of modifier raw materials, the rest is the same as Example 3): S1: 15wt% of MXene with a particle size of 50~100nm, 8wt% of modifier, 0.1wt% of photoinitiator, and 76.9wt% of uracil-modified PDMS are ultrasonically mixed for 30min, coated into a film, and dried at 80℃ for 1h to obtain a base layer with a thickness of 55μm; The modifier is iron oxide / graphene, polycaprolactone, polyethylene glycol thioglycolate, and branched polysiloxane in a mass ratio of 1:5:1. 12 wt% of MXene with a particle size of 50-100 nm was ultrasonically mixed with 88 wt% of uracil-modified PDMS for 30 min, coated into a film, and dried at 75 °C for 40 min to obtain a piezoelectric-triboelectric layer with a thickness of 40 μm. 30 wt% graphene and 70 wt% uracil-modified PDMS were ultrasonically mixed for 30 min, coated into a film, and dried at 70 °C for 30 min to obtain a photothermal layer with a thickness of 35 μm. S2: Spray adhesive onto the substrate surface at a rate of 0.15 mL / cm², attach the piezoelectric-triboelectric layer to the side with the adhesive, spray adhesive onto the piezoelectric-triboelectric layer surface at a rate of 0.15 mL / cm², attach the photothermal layer to the side with the adhesive, spray adhesive onto the photothermal layer surface at a rate of 0.15 mL / cm², attach a 12 μm polyimide film to the side with the adhesive, and hot-press and cure at 100℃ and 0.3 MPa for 5 min to obtain a passive pressure-heated electronic skin material.

[0029] Comparative Example 4 (adjust the addition ratio of the modifier raw materials, the rest is the same as Example 3) S1: 15wt% of MXene with a particle size of 50~100nm, 8wt% of modifier, 0.1wt% of photoinitiator, and 76.9wt% of uracil-modified PDMS were ultrasonically mixed for 30min, coated into a film, and dried at 80℃ for 1h to obtain a base layer with a thickness of 55μm; The modifier is iron oxide / graphene, polycaprolactone, polyethylene glycol thioglycolate, and branched polysiloxane in a mass ratio of 1:5:1. 12 wt% of MXene with a particle size of 50-100 nm was ultrasonically mixed with 88 wt% of uracil-modified PDMS for 30 min, coated into a film, and dried at 75 °C for 40 min to obtain a piezoelectric-triboelectric layer with a thickness of 40 μm. 30 wt% graphene and 70 wt% uracil-modified PDMS were ultrasonically mixed for 30 min, coated into a film, and dried at 70 °C for 30 min to obtain a photothermal layer with a thickness of 35 μm. S2: Spray adhesive onto the substrate surface at a rate of 0.15 mL / cm², attach the piezoelectric-triboelectric layer to the side with the adhesive, spray adhesive onto the piezoelectric-triboelectric layer surface at a rate of 0.15 mL / cm², attach the photothermal layer to the side with the adhesive, spray adhesive onto the photothermal layer surface at a rate of 0.15 mL / cm², attach a 12 μm polyimide film to the side with the adhesive, and hot-press and cure at 100℃ and 0.3 MPa for 5 min to obtain a passive pressure-heated electronic skin material.

[0030] Performance testing: (1) Take the substrate layer prepared in Examples 1-3 and Comparative Examples 1-4, place it on a glass slide, apply a DC voltage, and record it after the current stabilizes. Use this as the initial current value, and make a 5mm scratch with a scratch depth of 50μm on its surface; turn on 5mW / mm 2 The near-infrared light irradiation treatment was carried out for 60s for self-repair. After 6 cycles, the self-repair efficiency was calculated by using the change in current. (2) The passive pressure-heated electronic skin materials prepared in Examples 1-3 and Comparative Examples 1-4 were used. (1) The energy conversion efficiency and heating temperature under static pressure of 0.1KPa were tested. An 808nm laser with a laser power density of 3W / cm² was used during the test. 2 The distance was 5cm; the base layer of the passive pressure-heated electronic skin material was also subjected to the same "scratching-self-healing" cycle 6 times, and then the photothermal conversion efficiency was tested again to calculate the performance retention rate; see Table 1 for details: Table 1:

[0031] As can be seen from the comparative examples, increasing the amount of modifier or adjusting the amount of each raw material in the modifier will lead to a decrease in performance. However, the passive pressure-heated electronic skin material prepared by the scheme of Example 3 of the present invention has high energy conversion efficiency, good heating effect, good self-repair rate and good performance retention rate, and can be applied to various fields.

[0032] Application Example 1: Pre-preparation: Take 0.7 parts of 2-amino-4-hydroxy-6-methylpyrimidine and 7 parts of hexamethylene diisocyanate, heat to 100℃ and react for 16 h under nitrogen protection, wash with n-hexane and dry to obtain Upy-NCO; mix PDMS prepolymer and Upy-NCO at a mass ratio of 8:1, add 0.5 wt% of dibutyltin dilaurate of the total mass of PDMS prepolymer and Upy-NCO, stir at 60℃ for 2 h to obtain uracil-modified PDMS; KH-550 was mixed with anhydrous ethanol at a mass ratio of 1:10, stirred evenly, and allowed to stand for 10 minutes to obtain a silicon-oxygen coupling agent solution, which was used as a binder. Preparation of iron oxide / graphene: 10 parts of nano-Fe3O4 were dispersed in 80 parts of isopropanol and 10 parts of water, and 1 part of aminosilane coupling agent was added. Under nitrogen protection, the mixture was heated to 70℃ and stirred for 4 hours. After washing and drying, amino-iron oxide was obtained. 1 part of graphene oxide, 0.2 parts of NHS and 0.3 parts of EDC were dispersed in 150 parts of water, and 0.5 parts of amino-iron oxide and 0.1 parts of hydrazine hydrate were added. The mixture was heated to 85℃ and stirred for 2 hours. After washing and drying, iron oxide / graphene was obtained. Preparation of branched polysiloxane: The branched polysiloxane is prepared as follows: 45 parts of tetramethyltetravinylcyclotetrasiloxane and 0.15 parts of catalyst are added to 20 parts of methanol; the temperature is raised to 55°C under nitrogen protection, and a mixture of 35 parts of trimethoxyhydrosilane and 20 parts of methanol is added. The mixture is kept at this temperature for 8 hours, 3 parts of activated carbon are added, and the mixture is stirred for another 0.5 hours. The liquid is filtered and rotated at 38°C for 1 hour to obtain a silane monomer containing double bonds; 5 parts of the silane containing double bonds and 1 part of acetic anhydride are mixed, and 0.1 parts of tetra(trimethylsiloxy)titanium are added. The mixture is heated to 65°C and kept under vacuum for 12 hours to obtain the branched polysiloxane. S1: 15wt% of MXene with a particle size of 50~100nm, 8wt% of modifier, 0.1wt% of photoinitiator, and 76.9wt% of uracil-modified PDMS were ultrasonically mixed for 30min, coated into a film, irradiated with ultraviolet light at a wavelength of 365nm for 30s, and dried at 80℃ for 1h to obtain a base layer with a thickness of 55μm. The modifier is iron oxide / graphene, polycaprolactone, polyethylene glycol thioglycolate, and branched polysiloxane in a mass ratio of 1:3:2. 12 wt% of MXene with a particle size of 50-100 nm was ultrasonically mixed with 88 wt% of uracil-modified PDMS for 30 min, coated into a film, and dried at 75 °C for 40 min to obtain a piezoelectric-triboelectric layer with a thickness of 40 μm. 20 wt% graphene, 5 wt% CsPbBr3 quantum dots with a particle size of 5-8 nm and 75 wt% uracil-modified PDMS were ultrasonically mixed for 30 min, coated into a film, and dried at 70 °C for 30 min to obtain a photothermal layer with a thickness of 35 μm. S2: Spray adhesive onto the substrate surface at a rate of 0.15 mL / cm², attach the piezoelectric-triboelectric layer to the side with the adhesive, spray adhesive onto the piezoelectric-triboelectric layer surface at a rate of 0.15 mL / cm², attach the photothermal layer to the side with the adhesive, spray adhesive onto the photothermal layer surface at a rate of 0.15 mL / cm², attach a 12 μm polyimide film to the side with the adhesive, and hot-press and cure at 100℃ and 0.3 MPa for 5 min to obtain a passive pressure-heated electronic skin material.

[0033] Application Example 2: Pre-preparation: Take 0.7 parts of 2-amino-4-hydroxy-6-methylpyrimidine and 7 parts of hexamethylene diisocyanate, heat to 100℃ and react for 16 h under nitrogen protection, wash with n-hexane and dry to obtain Upy-NCO; mix PDMS prepolymer and Upy-NCO at a mass ratio of 8:1, add 0.5 wt% of dibutyltin dilaurate of the total mass of PDMS prepolymer and Upy-NCO, stir at 60℃ for 2 h to obtain uracil-modified PDMS; KH-550 was mixed with anhydrous ethanol at a mass ratio of 1:10, stirred evenly, and allowed to stand for 10 minutes to obtain a silicon-oxygen coupling agent solution, which was used as a binder. Preparation of iron oxide / graphene: 10 parts of nano-Fe3O4 were dispersed in 80 parts of isopropanol and 10 parts of water, and 1 part of aminosilane coupling agent was added. Under nitrogen protection, the mixture was heated to 70℃ and stirred for 4 hours. After washing and drying, amino-iron oxide was obtained. 1 part of graphene oxide, 0.2 parts of NHS and 0.3 parts of EDC were dispersed in 150 parts of water, and 0.5 parts of amino-iron oxide and 0.1 parts of hydrazine hydrate were added. The mixture was heated to 85℃ and stirred for 2 hours. After washing and drying, iron oxide / graphene was obtained. Preparation of branched polysiloxane: The branched polysiloxane is prepared as follows: 45 parts of tetramethyltetravinylcyclotetrasiloxane and 0.15 parts of catalyst are added to 20 parts of methanol; the temperature is raised to 55°C under nitrogen protection, and a mixture of 35 parts of trimethoxyhydrosilane and 20 parts of methanol is added. The mixture is kept at this temperature for 8 hours, 3 parts of activated carbon are added, and the mixture is stirred for another 0.5 hours. The liquid is filtered and rotated at 38°C for 1 hour to obtain a silane monomer containing double bonds; 5 parts of the silane containing double bonds and 1 part of acetic anhydride are mixed, and 0.1 parts of tetra(trimethylsiloxy)titanium are added. The mixture is heated to 65°C and kept under vacuum for 12 hours to obtain the branched polysiloxane. S1: 15wt% of MXene with a particle size of 50~100nm, 8wt% of modifier, 0.1wt% of photoinitiator, 10wt% of nano boron nitride, and 66.9wt% of uracil-modified PDMS were ultrasonically mixed for 30min, coated into a film, irradiated with ultraviolet light at a wavelength of 365nm for 30s, and dried at 80℃ for 1h to obtain a base layer with a thickness of 55μm. The modifier is iron oxide / graphene, polycaprolactone, polyethylene glycol thioglycolate, and branched polysiloxane in a mass ratio of 1:3:2. 12 wt% of MXene with a particle size of 50-100 nm was ultrasonically mixed with 88 wt% of uracil-modified PDMS for 30 min, coated into a film, and dried at 75 °C for 40 min to obtain a piezoelectric-triboelectric layer with a thickness of 40 μm. 30 wt% graphene and 70 wt% uracil-modified PDMS were ultrasonically mixed for 30 min, coated into a film, and dried at 70 °C for 30 min to obtain a photothermal layer with a thickness of 35 μm. S2: Spray adhesive onto the substrate surface at a rate of 0.15 mL / cm², attach the piezoelectric-triboelectric layer to the side with the adhesive, spray adhesive onto the piezoelectric-triboelectric layer surface at a rate of 0.15 mL / cm², attach the photothermal layer to the side with the adhesive, spray adhesive onto the photothermal layer surface at a rate of 0.15 mL / cm², attach a 12 μm polyimide film to the side with the adhesive, and hot-press and cure at 100℃ and 0.3 MPa for 5 min to obtain a passive pressure-heated electronic skin material.

[0034] Application Example 3: Pre-preparation: Take 0.7 parts of 2-amino-4-hydroxy-6-methylpyrimidine and 7 parts of hexamethylene diisocyanate, heat to 100℃ and react for 16 h under nitrogen protection, wash with n-hexane and dry to obtain Upy-NCO; mix PDMS prepolymer and Upy-NCO at a mass ratio of 8:1, add 0.5 wt% of dibutyltin dilaurate of the total mass of PDMS prepolymer and Upy-NCO, stir at 60℃ for 2 h to obtain uracil-modified PDMS; KH-550 was mixed with anhydrous ethanol at a mass ratio of 1:10, stirred evenly, and allowed to stand for 10 minutes to obtain a silicon-oxygen coupling agent solution, which was used as a binder. Preparation of iron oxide / graphene: 10 parts of nano-Fe3O4 were dispersed in 80 parts of isopropanol and 10 parts of water, and 1 part of aminosilane coupling agent was added. Under nitrogen protection, the mixture was heated to 70℃ and stirred for 4 hours. After washing and drying, amino-iron oxide was obtained. 1 part of graphene oxide, 0.2 parts of NHS and 0.3 parts of EDC were dispersed in 150 parts of water, and 0.5 parts of amino-iron oxide and 0.1 parts of hydrazine hydrate were added. The mixture was heated to 85℃ and stirred for 2 hours. After washing and drying, iron oxide / graphene was obtained. Preparation of branched polysiloxane: The branched polysiloxane is prepared as follows: 45 parts of tetramethyltetravinylcyclotetrasiloxane and 0.15 parts of catalyst are added to 20 parts of methanol; the temperature is raised to 55°C under nitrogen protection, and a mixture of 35 parts of trimethoxyhydrosilane and 20 parts of methanol is added. The mixture is kept at this temperature for 8 hours, 3 parts of activated carbon are added, and the mixture is stirred for another 0.5 hours. The liquid is filtered and rotated at 38°C for 1 hour to obtain a silane monomer containing double bonds; 5 parts of the silane containing double bonds and 1 part of acetic anhydride are mixed, and 0.1 parts of tetra(trimethylsiloxy)titanium are added. The mixture is heated to 65°C and kept under vacuum for 12 hours to obtain the branched polysiloxane. S1: 5 wt% of MXene with a particle size of 30~50, 8 wt% of modifier, 0.1 wt% of photoinitiator, and 86.9 wt% of uracil-modified PDMS were ultrasonically mixed for 30 min, coated into a film, irradiated with ultraviolet light at a wavelength of 365 nm for 30 s, and dried at 80 °C for 1 h to obtain a base layer with a thickness of 55 μm. The modifier is iron oxide / graphene, polycaprolactone, polyethylene glycol thioglycolate, and branched polysiloxane in a mass ratio of 1:3:2. 5 wt% of MXene with a particle size of 30-50 nm was ultrasonically mixed with 95 wt% of uracil-modified PDMS for 30 min, coated into a film, and dried at 75 °C for 40 min to obtain a piezoelectric-triboelectric layer with a thickness of 20 μm. 20 wt% graphene and 80 wt% uracil-modified PDMS were ultrasonically mixed for 30 min, coated into a film, and dried at 70 °C for 30 min to obtain a photothermal layer with a thickness of 15 μm. S2: Spray adhesive onto the substrate surface at a rate of 0.1 mL / cm², attach the piezoelectric-triboelectric layer to the side with the adhesive, spray adhesive onto the piezoelectric-triboelectric layer surface at a rate of 0.1 mL / cm², attach the photothermal layer to the side with the adhesive, spray adhesive onto the photothermal layer surface at a rate of 0.1 mL / cm², attach an 8 μm polyimide film to the side with the adhesive, and hot-press and cure at 100℃ and 0.3 MPa for 5 min to obtain a passive pressure-heated electronic skin material.

[0035] Application Example 4: Pre-preparation: Take 0.7 parts of 2-amino-4-hydroxy-6-methylpyrimidine and 7 parts of hexamethylene diisocyanate, heat to 100℃ and react for 16 h under nitrogen protection, wash with n-hexane and dry to obtain Upy-NCO; mix PDMS prepolymer and Upy-NCO at a mass ratio of 8:1, add 0.5 wt% of dibutyltin dilaurate of the total mass of PDMS prepolymer and Upy-NCO, stir at 60℃ for 2 h to obtain uracil-modified PDMS; KH-570 was mixed with anhydrous ethanol at a mass ratio of 1:10, stirred evenly, and allowed to stand for 10 minutes to obtain a silicon-oxygen coupling agent solution, which was used as a binder. Preparation of iron oxide / graphene: 10 parts of nano-Fe3O4 were dispersed in 80 parts of isopropanol and 10 parts of water, and 1 part of aminosilane coupling agent was added. Under nitrogen protection, the mixture was heated to 70℃ and stirred for 4 hours. After washing and drying, amino-iron oxide was obtained. 1 part of graphene oxide, 0.2 parts of NHS and 0.3 parts of EDC were dispersed in 150 parts of water, and 0.5 parts of amino-iron oxide and 0.1 parts of hydrazine hydrate were added. The mixture was heated to 85℃ and stirred for 2 hours. After washing and drying, iron oxide / graphene was obtained. Preparation of branched polysiloxane: The branched polysiloxane is prepared as follows: 45 parts of tetramethyltetravinylcyclotetrasiloxane and 0.15 parts of catalyst are added to 20 parts of methanol; the temperature is raised to 55°C under nitrogen protection, and a mixture of 35 parts of trimethoxyhydrosilane and 20 parts of methanol is added. The mixture is kept at this temperature for 8 hours, 3 parts of activated carbon are added, and the mixture is stirred for another 0.5 hours. The liquid is filtered and rotated at 38°C for 1 hour to obtain a silane monomer containing double bonds; 5 parts of the silane containing double bonds and 1 part of acetic anhydride are mixed, and 0.1 parts of tetra(trimethylsiloxy)titanium are added. The mixture is heated to 65°C and kept under vacuum for 12 hours to obtain the branched polysiloxane. S1: 15wt% of MXene with a particle size of 50~100nm, 8wt% of modifier, 0.1wt% of photoinitiator, 15wt% of acrylate-based polyethylene glycol polycaprolactone, and 61.9wt% of uracil-modified PDMS were ultrasonically mixed for 30min, coated into a film, irradiated with ultraviolet light at a wavelength of 365nm for 30s, and dried at 80℃ for 1h to obtain a base layer with a thickness of 55μm. The modifier is iron oxide / graphene, polycaprolactone, polyethylene glycol thioglycolate, and branched polysiloxane in a mass ratio of 1:3:2. 12 wt% of MXene with a particle size of 50-100 nm was ultrasonically mixed with 72.9 wt% of uracil-modified PDMS, 15 wt% of acrylate-based polyethylene glycol polycaprolactone, and 0.1 wt% of photoinitiator for 30 min, coated into a film, irradiated with ultraviolet light at a wavelength of 365 nm for 30 s, and dried at 75 °C for 40 min to obtain a piezoelectric-triboelectric layer with a thickness of 40 μm. 30 wt% graphene, 54.9 wt% uracil-modified PDMS, 15 wt% acrylate-based polyethylene glycol polycaprolactone, and 0.1 wt% photoinitiator were ultrasonically mixed for 30 min, coated into a film, irradiated with ultraviolet light at a wavelength of 365 nm for 30 s, and dried at 70 °C for 30 min to obtain a photothermal layer with a thickness of 35 μm. S2: Spray adhesive onto the substrate surface at a rate of 0.15 mL / cm², attach the piezoelectric-triboelectric layer to the side with the adhesive, spray adhesive onto the piezoelectric-triboelectric layer surface at a rate of 0.15 mL / cm², attach the photothermal layer to the side with the adhesive, spray adhesive onto the photothermal layer surface at a rate of 0.15 mL / cm², attach a 12 μm polyimide film to the side with the adhesive, and hot-press and cure at 100℃ and 0.3 MPa for 5 min to obtain a passive pressure-heated electronic skin material.

[0036] Testing and Discussion: Application Example 1, with the addition of CsPbBr3 quantum dots, achieved a conversion efficiency of 35% and a heating temperature of 38.8℃ under 100 lux low light. It operated continuously for 72 hours under natural indoor light without interruption of heat output, making it suitable for indoor use. Application Example 2, with the addition of nano-boron nitride, achieved a heating temperature of 42.0℃. After 100 cycles of thermal shock (-40℃→120℃), it retained 80% of its performance, demonstrating high-temperature tolerance and suitability for 120℃ industrial environments. Application Example 3, with its thin overall thickness, can be bent to a 5mm diameter curved surface, achieving a heating temperature of 39.5℃. It exhibits high biocompatibility with human tissue, with no irritation, making it suitable for localized hyperthermia of lesions in minimally invasive surgery. Application Example 4 further incorporates a flexible component, with a heating temperature of 41.2℃, and a measured elongation at break of 250%. After 10,000 bends (radius 2mm), the performance retention rate is 90%. Under dynamic pressure of 0.8MPa, the conversion efficiency is 85%, which is suitable for heating under bending pressure in robot knee joints, and there are no wrinkles or damage during bending.

[0037] In summary, the self-healing photothermal graphene passive pressure-thermal electronic skin material prepared by this method has high energy conversion efficiency, good heating effect, good self-healing performance, and a wide range of applications.

[0038] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

Claims

1. A method for preparing a self-healing photothermal graphene passive pressure-heated electronic skin material, characterized in that: Includes the following steps: Step 1: Mix MXene, modifier, photoinitiator, and uracil-modified PDMS to obtain a polymer composition; Step 2: Coat the polymer composition into a film to form a base layer; then stack it sequentially with the piezoelectric-triboelectric layer, photothermal layer, and encapsulation layer, and bond the contact interfaces using a silicone coupling agent solution; hot-press and cure to obtain a passive pressure-heated electronic skin material; The raw materials of the piezoelectric-triboelectric layer include 5-12 wt% MXene by mass percentage, with the remainder being polymer materials; the raw materials of the photothermal layer include 5-12 wt% thermal filler by mass percentage, with the remainder being polymer materials; the encapsulation layer includes one of polyimide film and polytetrafluoroethylene film; the polymer materials include one or two of PDMS and polycaprolactone; the thermal filler includes graphene; The raw materials of the polymer composition used in the base layer are, by mass percentage: 5-15 wt% MXene, 3-9 wt% modifier, 0.06-0.18 wt% photoinitiator, and the remainder is uracil-modified PDMS; The modifier comprises iron oxide / graphene, polycaprolactone, polyethylene glycol thioglycolate, and branched polysiloxane in a mass ratio of (0.5~1.5):(1.5~4.5):(1~3). The preparation method of the iron oxide / graphene is as follows: (1) Nano-iron oxide is modified with aminosilane coupling agent to obtain amino iron oxide; (2) Graphene oxide and NHS-EDC are dispersed in water, amino iron oxide and hydrazine hydrate are added, the temperature is raised to 80~85℃, and the mixture is stirred at a constant temperature for 1~2 hours. After washing and drying, iron oxide / graphene is obtained. The mass ratio of graphene oxide to amino iron oxide is 1:(0.5~0.6).

2. The preparation method of the self-healing photothermal graphene passive pressure-thermal electronic skin material according to claim 1, characterized in that: The preparation method of the uracil ketone modified PDMS is as follows: (1) Take 2-amino-4-hydroxy-6-methylpyrimidine and hexamethylene diisocyanate, heat to 95~100℃ under nitrogen protection and react, then treat to obtain Upy-NCO; (2) Mix hydroxyl-terminated PDMS prepolymer and Upy-NCO, add dibutyltin dilaurate, stir and react to obtain modified PDMS.

3. The preparation method of the self-healing photothermal graphene passive pressure-heated electronic skin material according to claim 2, characterized in that: In the raw materials of Upy-NCO, the mass ratio of 2-amino-4-hydroxy-6-methylpyrimidine to hexamethylene diisocyanate is (0.5~1):(5~10). In the raw materials of the modified PDMS, the mass ratio of PDMS prepolymer to Upy-NCO is (8~10):1, and the amount of dibutyltin dilaurate added is 0.3~0.5wt% of the total mass of PDMS prepolymer and Upy-NCO.

4. The preparation method of the self-healing photothermal graphene passive pressure-thermal electronic skin material according to claim 1, characterized in that: The siloxane coupling agent solution is composed of silane coupling agent and anhydrous ethanol in a mass ratio of 1:(8~10); the spraying amount of the siloxane coupling agent solution at the contact interface is 0.1~0.2 mL / cm. 2 .

5. The preparation method of the self-healing photothermal graphene passive pressure-thermal electronic skin material according to claim 1, characterized in that: The preparation method of the branched polysiloxane is as follows: (1) Tetramethyltetravinylcyclotetrasiloxane and catalyst are added to methanol; under an inert gas atmosphere, the temperature is raised to 50~55℃; a trimethoxyhydrosilane-methanol mixture is added, and the reaction is carried out for 8~12h. After post-treatment, a silane containing double bonds is obtained; (2) The silane containing double bonds and acetic anhydride are mixed, tetra(trimethylsiloxy)titanium is added, the temperature is raised to 60~65℃, and the temperature is kept under vacuum for 10~15h to obtain the branched polysiloxane.

6. The method for preparing the self-healing photothermal graphene passive pressure-heated electronic skin material according to claim 5, characterized in that: The silane containing double bonds comprises the following raw materials, by mass parts: 40-50 parts tetramethyltetravinylcyclotetrasiloxane, 0.1-0.15 parts catalyst, and 30-40 parts trimethoxyhydrosilane; the branched polysiloxane comprises the following raw materials, by mass parts: 5-6 parts silane containing double bonds, 0.8-1.2 parts acetic anhydride, and 0.1-0.2 parts tetra(trimethylsiloxy)titanium.

7. The passive pressure-heated electronic skin material prepared by the preparation method of the self-healing photothermal graphene passive pressure-heated electronic skin material according to any one of claims 1 to 6, characterized in that: The passive pressure-heated electronic skin material comprises, in sequence, a substrate layer, a piezoelectric-triboelectric layer, a photothermal layer, and an encapsulation layer; the thickness of the substrate layer is 50~60μm, the thickness of the piezoelectric-triboelectric layer is 20~40μm, the thickness of the photothermal layer is 15~40μm, and the thickness of the encapsulation layer is 8~15μm.

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