Bionic silica gel electronic skin based on graphene heating and preparation method thereof

Abstract

The invention relates to the technical field of bionic silica gel electronic skin, in particular to bionic silica gel electronic skin based on graphene heating and a preparation method of the bionic silica gel electronic skin. The device is composed of a graphene-polydimethylsiloxane composite functional film, and a micro-dome array and an isolation channel are constructed in the device. The micro-dome is used as a sensing unit for enriching graphene, and the isolation channel realizes pixelated electrical isolation of adjacent units. A patterned electrode grid is prepared on the surface of the functional film so as to form an independent sensing-heating pixel unit. The single pixel unit can work in a pressure sensing mode, a temperature sensing mode or a regionalized heating mode in a time-sharing mode through the piezoresistance, the negative temperature coefficient and the Joule effect of graphene and time-sharing multiplexing control of an external circuit, and sensing-heating integration is achieved. The problems of thermal crosstalk, response hysteresis and high energy consumption of a traditional multi-layer structure are solved, and the multi-layer structure has the advantages of being simple in structure, good in flexibility and low in power consumption and is suitable for the fields of robots, intelligent prostheses and the like.

Description

Technical Field

[0001] This invention relates to the field of biomimetic silicone electronic skin technology, specifically to a graphene-based heated biomimetic silicone electronic skin and its preparation method. Background Technology

[0002] Currently, bionic electronic skin with thermal feedback function typically adopts a "sandwich"-like multi-layered stacked structure, that is, independent pressure sensing layers, independent heating layers, and independent temperature sensing layers are assembled by bonding. This structure has inherent drawbacks:

[0003] First, functional isolation physically separates sensing and heating, resulting in long signal transmission paths and slow thermal response, failing to simulate the physiological characteristics of the close interweaving and rapid coordination of tactile and thermal nerve endings in human skin. Second, the structure is complex and unreliable; multi-layer stacking increases overall thickness and reduces flexibility, and the interface is prone to delamination under repeated deformation, affecting service life. Finally, there are issues of thermal crosstalk and high energy consumption; when a localized thermal feedback is needed, the independent, large-area heating layer has to heat the entire area, resulting in energy waste, and the heat source of the heater will cause "thermal crosstalk" to nearby temperature sensors, interfering with the accurate measurement of ambient temperature.

[0004] Although graphene heating materials have the advantages of being thin, flexible, and providing uniform heating, the aforementioned problems cannot be fundamentally solved if they are simply embedded as independent heating layers in the traditional structures described above. Summary of the Invention

[0005] The purpose of this invention is to provide a biomimetic silicone electronic skin based on graphene heating and its preparation method. It abandons the traditional idea of ​​"functional layer stacking" and uses a single functional composite material layer based on graphene to simultaneously possess three functions: pressure sensing, temperature sensing, and regionalized precise heating, thereby achieving true "sensing-heating" integration and solving the problems mentioned in the background art.

[0006] To achieve the above objectives, in one aspect, the present invention provides a biomimetic silicone electronic skin based on graphene heating, comprising the following structure:

[0007] Matrix: Medical-grade polydimethylsiloxane (PDMS) silicone, providing flexibility and biocompatibility.

[0008] Active material: Graphene nanosheets with high conductivity and high negative temperature coefficient (NTC) properties are uniformly dispersed in a PDMS matrix.

[0009] Core structure: Within the graphene-polydimethylsiloxane composite functional film, a "micro-dome array" and "isolation channels" are constructed using template or imprinting techniques; among which:

[0010] Microdome: Each dome is a conductive unit enriched with graphene, serving as a sensitive touch and temperature sensing point.

[0011] Isolation trenches: The graphene concentration in the trenches is extremely low or non-existent, forming a relatively insulating physical isolation zone that electrically isolates adjacent microdomes.

[0012] By constructing electrically isolated "micro-dome" pixel units within the same composite material layer, and utilizing the piezoresistive effect, negative temperature coefficient (NTC) effect, and Joule effect of graphene material, and through time-division multiplexing control of external circuitry, each pixel unit can operate in pressure sensing, temperature sensing, or localized heating modes. The "isolation channel" ensures the independence of the electrical signals of each pixel unit, and is a key structure for achieving precise localized sensing and control.

[0013] Functionalized electrodes: On the lower surface of the graphene-polydimethylsiloxane composite functional film, an independent yet flexible metal electrode grid is fabricated using laser etching and masking techniques. Each electrode corresponds to one or more micro-domes, forming an independent "sensing-heating pixel unit".

[0014] This invention utilizes the piezoresistive effect of graphene for pressure sensing, its negative temperature coefficient (NTC) for temperature sensing, and its Joule effect for heating. A designed "micro-dome array" serves as both the sensing and execution units, with pixel-level isolation achieved through "isolation channels." The external control circuit employs time-division multiplexing technology to rapidly switch each pixel unit, allowing it to operate in sensing or heating modes at different times. This enables dynamic, zoned control of multiple functions using a single material and structure, fundamentally solving the problems of functional isolation, thermal crosstalk, and complexity inherent in traditional structures.

[0015] Furthermore, the cross-sectional shape of the microdome is circular, elliptical, or polygonal, with a bottom diameter ranging from 50μm to 200μm, a height ranging from 20μm to 100μm, and a center-to-center distance between adjacent microdomes ranging from 100μm to 300μm.

[0016] On the other hand, the present invention provides a method for preparing biomimetic silicone electronic skin based on graphene heating, comprising the following steps:

[0017] S1. Composite preparation: Graphene nanosheets are uniformly dispersed in PDMS prepolymer by high-speed shear stirring to form a conductive composite.

[0018] S2. Microstructure Molding: The composite material is injected into a mold with a reversible microdome and channel structure. After vacuuming and curing, it is demolded to obtain a graphene-polydimethylsiloxane composite functional film with embedded multi-level microstructures. Specifically, in the graphene-silicone composite functional film, the mass fraction of graphene nanosheets is 0.5%-5%, the number of graphene nanosheets is less than 10 layers, and the sheet diameter is 1μm-20μm.

[0019] S3. Patterned electrode preparation: On the flat lower surface of the graphene-polydimethylsiloxane composite functional film, grooves of the electrode pattern are etched using laser direct writing technology, and then gold or silver is filled in by vacuum evaporation or inkjet printing to form a flexible electrode grid.

[0020] S4. Integration and Packaging: Connect the prepared core functional film to the flexible FPC circuit and encapsulate it with a thin layer of silicone to complete the preparation of the electronic skin.

[0021] Furthermore, the electronic skin of this invention is controlled by a multiplexed circuit, and each "pixel unit" can operate in three modes:

[0022] Firstly, the pressure sensing mode: a constant small voltage is applied to the unit and the current is monitored. When the dome is deformed by pressure, the change in the spacing of the internal graphene network causes the resistance to increase (piezoresistive effect). The pressure is sensed with high precision through the change in resistance.

[0023] Secondly, the temperature sensing mode: Utilizing the inherent NTC effect of graphene (resistance decreases as temperature rises), the ambient temperature can be inferred by measuring the static resistance of the measuring unit when there is no pressure or after compensating for the pressure signal.

[0024] Third, localized heating mode: When thermal feedback is required, a larger operating voltage is applied to a specific "pixel unit". Due to the resistance of the graphene network in this unit, Joule heating is generated, thereby achieving precise and localized heating. The temperature of the heated area can be controlled in real time by feedback from its own resistance change (NTC effect).

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] This graphene-based biomimetic silicone electronic skin and its fabrication method integrate pressure sensing, temperature sensing, and heating functions into a single physical structure layer, fundamentally eliminating interlayer interfaces and significantly improving the device's flexibility, reliability, and lifespan. Because each "pixel unit" can be independently addressed and heated, the system can heat only the touched fingertip area, while the back of the hand remains at room temperature. This greatly reduces power consumption and enables a realistic thermal interaction experience. For example, the prosthesis can sense and grasp an ice-cold beverage can, providing thermal feedback only in the localized area in contact with the can.

[0027] Secondly, since sensing and heating are the same physical entity, the change in the unit's own resistance during heating directly reflects its temperature, achieving the most direct and lag-free closed-loop temperature control and completely avoiding the thermal interference problem of the heater on the independent temperature sensor in traditional structures. Because separate sensing and heating layers are eliminated, the entire electronic skin structure is thinner and simpler, and the fabrication steps are correspondingly reduced, which is beneficial for cost reduction and large-scale production. Attached Figure Description

[0028] Figure 1 This is an overall flowchart of Embodiment 1 of the present invention. Detailed Implementation

[0029] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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.

[0030] Example 1: The purpose of this embodiment of the invention is to provide a method for preparing biomimetic silicone electronic skin with integrated sensing and heating functions, including the following steps ( Figure 1 ):

[0031] (1) Mold preparation: A truncated conical microdome array was fabricated on a silicon wafer using standard photolithography and etching techniques. Each microdome has a bottom diameter of 100 μm, a height of 50 μm, and a spacing of 150 μm.

[0032] A self-assembled monolayer (such as tridecafluoro-1,1,2,2-tetrahydrooctyltrichlorosilane) is formed on the surface of the silicon mold using vapor deposition as a release agent.

[0033] The microdome array structure and size used in this embodiment are only examples. The shape, size and spacing of the microstructure can be designed and adjusted according to different sensitivity, range and spatial resolution requirements.

[0034] (2) Formulation of graphene / silicone composite:

[0035] 100 mg of few-layer graphene nanosheets (<5 layers, 5-10 μm diameter) were dispersed in 20 mL of anhydrous ethanol and sonicated (300 W) for 1 hour to form a uniform dispersion.

[0036] The above dispersion was mixed with 10g of liquid silicone rubber (such as Dow Corning Sylgard 184 component A) and mechanically stirred (500 rpm for 2 hours) to achieve initial mixing.

[0037] Place the mixture in a planetary centrifugal mixer and degas and stir for 5 minutes at an orbital speed of 2000 rpm and a rotational speed of 1000 rpm to ensure that the graphene is evenly dispersed and free of bubbles.

[0038] Finally, add 1g of silicone rubber curing agent (Sylgard 184 component B), and stir again in a centrifuge at 1500rpm for 2 minutes to degas and obtain a homogeneous, curable graphene / silicone composite.

[0039] (3) Functional layer molding and curing: Pour the prepared composite onto the pretreated silicone mold; use a scraper to remove excess composite to ensure that the composite fully fills the microdome cavity. Place the mold in a vacuum drying oven and evacuate at -0.1 MPa for 15 minutes to thoroughly remove air bubbles from the interior of the composite and the microstructure. Subsequently, transfer the mold to a forced-air drying oven and heat at 80°C for 1 hour to allow the silicone to fully cure.

[0040] (4) Electrode Patterning: The cured graphene / silicone composite film was carefully peeled off from the mold. At this point, one side of the film was flat, and the other side was an active surface with a micro-dome array. On the flat side of the film, a 10 nm thick chromium adhesion layer was first deposited using magnetron sputtering, followed by a 100 nm thick gold layer. Laser etching was used to etch the gold layer into the designed 5x5 interdigitated electrode array, thereby dividing the composite functional layer into 25 independent, individually addressable pixel units.

[0041] (5) Lead connection: The pins of the flexible printed circuit board (FPCB) are aligned with the pads of the gold electrode using an anisotropic conductive film (ACF), and electrical interconnection is achieved by a hot press bonding machine (temperature 150℃, pressure 1MPa, time 10 seconds).

[0042] This embodiment creates a single functional layer that combines piezoresistive, thermosensitive, and thermal effects by directly mixing conductive filler (graphene) with a polymer substrate (silicone) and molding it in one step. This fundamentally avoids the interface problems and fabrication complexities associated with multilayer structures. Simultaneously with the molding of the composite material, a microstructure array is directly replicated. These microstructures not only enhance the sensitivity and linear range of pressure sensing, but the grooves between them also naturally create physical and electrical isolation between pixel units, simplifying the pixelation process.

[0043] The above process parameters (such as ultrasonic power, rotation speed, time, etc.) are the preferred solutions for obtaining the best dispersion effect. Under the concept of this invention, those skilled in the art can make appropriate adjustments according to the actual equipment and material conditions without departing from the principle of this invention.

[0044] Example 2: The purpose of this example is to provide a method for preparing a biomimetic silicone electronic skin with better graphene dispersion and stronger bonding between the electrode and the functional layer, including the following steps:

[0045] (1) Graphene pretreatment and composite preparation: The surface of few-layer graphene nanosheets was modified in an ethanol solution of 3-aminopropyltriethoxysilane (APTES) to improve their compatibility and dispersion stability in the silica matrix.

[0046] The modified graphene and a portion of component A silica gel (accounting for half of the total component A) were first dispersed by rolling using a three-roll mill, and the rolling process was repeated five times until the composite was fine and uniform. This method can apply huge shear forces, effectively breaking up graphene aggregates.

[0047] Then mix this high-concentration mother slurry with the remaining silica gel component A, dilute and stir evenly using a planetary centrifuge, and follow the same steps as in Example 1.

[0048] (2) Functional layer molding and electrode integration: The “pre-lay electrode” method is adopted. Before the functional layer is molded, the patterned gold electrode (prepared on a flexible polyimide film) is placed at the bottom of the mold, ensuring that the electrode pattern side faces upward.

[0049] The composite was then poured into a mold with electrodes and vacuum degassing and curing were performed.

[0050] After curing, the electrode is firmly embedded in the surface of the composite functional layer, forming a strong mechanical interlock with the silicone, which greatly improves the interface stability of the electrode-functional layer and is suitable for applications involving repeated bending.

[0051] This embodiment employs surface modification and high-shear dispersion using a three-roll mill to ensure nanoscale uniform dispersion of graphene in viscous silicone, thereby guaranteeing the consistency of electrical properties of each pixel unit. The "pre-deposited electrode" method creates an integrated electrode-functional layer structure, solving the problems of poor adhesion and easy detachment that may exist in post-deposited electrodes, and significantly improving the mechanical durability of the device.

[0052] Example 3: The purpose of this example is to provide a method for preparing a biomimetic silicone electronic skin with a functionally graded structure, including the following steps:

[0053] (1) Prepare two complexes of different concentrations:

[0054] High-concentration composite (sensing layer): The graphene content is 3wt%, and the preparation method is the same as in Example 2. It is used to manufacture a highly sensitive sensing area.

[0055] Low-concentration composite (transition layer): with a graphene content of 0.5 wt%, mainly used to improve interfacial bonding and as insulation.

[0056] (2) Preparation of gradient functional layer: First, pour a thin layer of low-concentration composite into the mold and slightly tilt the mold to spread it evenly. Pre-cur it at 60°C for 10 minutes to make its surface slightly tacky. Then, pour a high-concentration composite on the pre-cured low-concentration composite, and then perform complete vacuum degassing and final curing at 80°C for 1 hour.

[0057] The final product is a composite functional layer with a concentration gradient: the bottom (electrode side) has a low concentration, providing good electrode contact and mechanical buffering; the top (contact surface) has a high concentration, providing excellent sensing performance.

[0058] This embodiment demonstrates that the fabrication method of the present invention is not limited to homogeneous structures. It can construct complex structures with compositional or functional gradients through multi-step casting / printing, thereby optimizing the overall performance of the device (such as sensitivity, stability, and durability). This provides strong process support for customized electronic skins.

[0059] Example 1: This embodiment conducts basic performance comparison tests to verify the sensing and heating performance.

[0060] (1) Experimental objective: To quantitatively compare the differences between the electronic skin of the present invention and traditional structures in terms of core performance parameters, including pressure sensitivity, response speed, heating efficiency and stability.

[0061] (2) Test sample

[0062] Experimental group: Bionic silicone electronic skin prepared in Example 1 of this invention (size: 2 cm × 2 cm, containing 4 × 4 pixel units).

[0063] Control group: Electronic skin with a sandwich structure of "piezoresistive layer + insulating layer + heating layer" prepared by traditional process.

[0064] (3) Test equipment: universal testing machine, high-precision digital source meter, high-speed data acquisition card, infrared thermal imager, constant temperature chamber.

[0065] (4) Pressure sensing performance test, method: apply 0-50kPa linear pressure using a universal testing machine, record the resistance change of the source meter, calculate the sensitivity, and the results are shown in Table 1.

[0066] Table 1 Quantitative Comparison of Pressure Sensing Performance

[0067] Performance parameters experimental group control group Low-pressure sensitivity (0-5 kPa) <![CDATA[85.2±3.5kPa -1 ]]> <![CDATA[12.8±1.2kPa -1 ]]> High range sensitivity (5-50 kPa) <![CDATA[25.6±1.8kPa -1 ]]> <![CDATA[9.5±0.9 kPa -1 ]]> Response time (10%-90%) 24.5±2.1ms 85.3±5.5ms Minimum detection threshold <10Pa ~100 Pa

[0068] (5) Electrothermal drive performance test, method: apply a 3V step voltage to a single pixel unit, and record the heating process and steady-state temperature distribution with an infrared thermal imager. The results are shown in Table 2.

[0069] Table 2 Quantitative Comparison of Electrothermal Performance

[0070] Performance parameters experimental group control group performance advantages Heating time (25℃-60℃) 4.8s 16.5s Speed ​​increased by 70% Temperature uniformity (ΔT) < 2.0℃ ＞10℃ Uniformity improved by 5 times Steady-state power consumption (60℃) 210±10mW 280±25mW Energy efficiency improved by 25%

[0071] (6) Cyclic stability test, method: 100 cycles of alternating "pressure loading-unloading" and "heating-cooling" were performed on the same unit. The results are as follows:

[0072] After 100 cycles, the pressure signal attenuation in the experimental group was < 5%, and the steady-state temperature fluctuation was < 3%; while the pressure signal attenuation in the control group was > 15%, and the steady-state temperature drop was > 5%, which proves that the integrated structure of the present invention has good mechanical and thermal stability.

[0073] In summary, as shown in Tables 1 and 2, the present invention is significantly superior to traditional technologies in all core indicators of pressure sensing and electrothermal actuation.

[0074] Experimental Example 2: The purpose of this experiment is to verify whether a single pixel unit can use a single electrical signal to distinguish and decouple external pressure and temperature stimuli in real time and accurately.

[0075] (1) Test sample: a single pixel unit of the electronic skin of Example 1 of the present invention.

[0076] (2) Test equipment: Peltier temperature control table, micro actuator, high-precision digital source meter, data acquisition system.

[0077] (3) Establish a calibration database. Method: In a controllable temperature chamber, measure the steady-state resistance (R) of the pixel unit under different combinations of temperature (T) and pressure (P) to form a data matrix. The results are shown in Table 3.

[0078] Table 3 Resistance-Temperature-Pressure Response Matrix (Unit: kΩ)

[0079] resistor R P=0 kPa P=1 kPa P=2 kPa P=5 kPa T=20℃ 105.2 98.5 92.1 80.3 T=30℃ 98.8 92.4 86.3 75.1 T=40℃ 92.9 86.8 81.0 70.5 T=50℃ 87.4 81.6 76.1 66.2

[0080] (4) Dynamic decoupling verification

[0081] Method: A compound stimulus was applied, with temperature varying from 30℃ to 40℃ and pressure varying from 0 to 2 kPa simultaneously (with a phase difference). Only the resistance signal was collected, and decoupling was performed using the matrix described above. The results are shown in Table 4.

[0082] Table 4 Decoupling accuracy data

[0083] physical quantity Actual input signal This invention decouples the output Decoupling error temperature 30.0℃↔40.0℃ 30.1℃↔39.8℃ ≤0.3℃ pressure 0.0 kPa ↔ 2.0 kPa 0.05 kPa ↔ 1.95 kPa ≤0.05kPa

[0084] As shown in Tables 3 and 4, this invention, through innovative materials and calibration methods, achieves high-precision decoupling of two physical quantities, temperature and pressure, using only a single electrical signal, simplifying system complexity and solving technical challenges in multimodal sensing.

[0085] Test Example 3: The purpose of this test example is to verify the ability of the present invention to achieve multi-point tactile perception and local selective heating in the dexterous operation of a robot.

[0086] (1) Test sample: Electronic skin of embodiment 1 of the present invention (2×2 pixel unit) attached to the gripper of a two-finger robot.

[0087] (2) Test scenario and equipment: metal block (25°C), ice block (0°C), robot control system, infrared thermal imager.

[0088] (3) Scene simulation and results: Simulate the complex task of a robot coming into contact with objects of different temperatures at the same time.

[0089] Task Description: Control the gripper so that Pixel (1,1) and (1,2) contact the metal block and Pixel (2,1) contact the ice block.

[0090] Control command: The system automatically identifies the contact position and only activates heating for the pixels that are in contact with the metal block (target: 40°C).

[0091] The results are shown in Table 5.

[0092] Table 5. Results of Tactile Perception and Thermal Control

[0093] pixel unit Contact object Sensed pressure (kPa) Heating command Measured temperature (°C) in conclusion Pixel (1,1) metal block 2.5 Start (3V) 40.2 Successful selective heating Pixel (1,2) metal block 2.8 Start (3V) 39.8 Successful selective heating Pixel (2,1) ice cubes 1.9 Off (0V) 25.5 No heating required to avoid melting. Pixel (2,2) none 0.0 Off (0V) 25.5 Error triggered

[0094] As shown in Table 5, this invention achieves 100% tactile positioning accuracy, 100% thermal control zoning accuracy (no crosstalk), and high-precision temperature control capability (error <1.0℃). This demonstrates its high application value in the dexterous operation of robots requiring precise tactile perception and active thermal management.

[0095] Through the above quantitative data, this invention demonstrates that, compared with existing technologies, the "bionic silicone electronic skin based on graphene heating" not only achieves a comprehensive improvement in core performance indicators, but also overcomes two technical challenges: multimodal perception decoupling and spatial independent control. This lays a solid technical foundation for its practical application in next-generation robots, intelligent prostheses, and advanced human-computer interaction systems.

[0096] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A biomimetic silicone electronic skin based on graphene heating, characterized in that, include: A graphene-polydimethylsiloxane composite functional film has a microdome array and isolation channels built inside it. The microdome is a conductive unit enriched with graphene, and the isolation channels are used to electrically isolate adjacent microdomes. Additionally, a patterned electrode grid is disposed on the surface of the graphene-polydimethylsiloxane composite functional film, the electrode grid comprising multiple independent electrodes, each electrode being electrically connected to one or more of the microdome to form an independent sensing-heating pixel unit.

2. The biomimetic silicone electronic skin based on graphene heating according to claim 1, characterized in that, The cross-sectional shape of the microdome is circular, elliptical, or polygonal, with a bottom diameter ranging from 50μm to 200μm, a height ranging from 20μm to 100μm, and a center-to-center distance between adjacent microdomes ranging from 100μm to 300μm.

3. The biomimetic silicone electronic skin based on graphene heating according to claim 1, characterized in that, The graphene in the graphene-polydimethylsiloxane composite functional film is a few-layer graphene nanosheet, with a mass fraction of 0.5%-5%, and the number of layers of the graphene nanosheet is less than 10, with a sheet diameter of 1μm-20μm.

4. The biomimetic silicone electronic skin based on graphene heating according to claim 1, characterized in that, The patterned electrode grid is formed by laser etching the surface of the graphene-polydimethylsiloxane composite functional film and filling it with metal, or by pre-laying flexible electrodes and integrally forming them with the graphene-polydimethylsiloxane composite functional film.

5. The biomimetic silicone electronic skin based on graphene heating according to claim 1, characterized in that, The electrode is a gold electrode or a silver electrode.

6. A method for preparing the graphene-based heated biomimetic silicone electronic skin according to any one of claims 1-5, characterized in that, Includes the following steps: S1. Graphene nanosheets are uniformly dispersed in polydimethylsiloxane prepolymer by high-speed shear stirring to form a conductive composite. S2. The conductive composite is injected into a mold with a reverse micro-dome and channel structure. After vacuuming and curing, the mold is demolded to obtain a graphene-polydimethylsiloxane composite functional film with micro-dome array and isolation channels. S3. Independent patterned electrodes are prepared on the flat surface of the graphene-polydimethylsiloxane composite functional film to form the patterned electrode grid.

7. The method for preparing biomimetic silicone electronic skin based on graphene heating according to claim 6, characterized in that, The high-speed shear mixing includes the use of a planetary centrifugal mixer or a three-roll mill; before using the three-roll mill, the graphene nanosheets are surface modified with 3-aminopropyltriethoxysilane.

8. The method for preparing biomimetic silicone electronic skin based on graphene heating according to claim 6, characterized in that, The steps for preparing the patterned electrode are as follows: using laser direct writing technology to etch grooves for the electrode pattern, and then filling them with gold or silver through vacuum evaporation or inkjet printing.

9. The method for preparing biomimetic silicone electronic skin based on graphene heating according to claim 6, characterized in that, The step of preparing the patterned electrode is the "pre-lay electrode" method, which specifically includes: first, placing the patterned gold electrode at the bottom of the mold, and then pouring the conductive composite into the mold for curing, so that the electrode is embedded in the surface of the graphene-polydimethylsiloxane composite functional film.

10. The method for preparing biomimetic silicone electronic skin based on graphene heating according to claim 6, characterized in that, The molding steps of the conductive composite include gradient molding: first, a low graphene concentration composite is poured into a mold and pre-cured, then a high graphene concentration composite is poured and finally cured.

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