A humanoid robot wearable flexible vibration perception sensor and a method of manufacturing the same

Abstract

The present application relates to a kind of humanoid robot wearable flexible vibration perception sensor and its preparation method.The sensor structure includes upper and lower packaging layer, moisture absorption layer, hydrogel layer, graphene layer, electrode layer and flexible circuit board.The upper and lower packaging layer protects internal structure, the moisture absorption layer enhances the moisture absorption capacity in environment, the hydrogel layer maintains moisture and forms concentration gradient, the graphene layer enhances sensor sensitivity, the electrode layer collects ion migration to generate voltage, and the flexible circuit board embeds signal amplification circuit and wireless transmission module.The present application is innovative in that it uses ion migration between hydrogel layer and graphene layer to convert vibration signal into voltage change, achieving accurate vibration perception.The sensor has high sensitivity, fast response and good flexibility, and is suitable for integration into humanoid robot, improving its environmental perception and interaction performance.

Description

Technical Field

[0001] This invention relates to the field of flexible sensor technology, and in particular to a wearable flexible vibration sensing sensor for humanoid robots and its fabrication method. Background Technology

[0002] With the rapid development of robotics technology, humanoid robots are being used more and more widely in industries, services, and healthcare. To improve the intelligence and interaction capabilities of humanoid robots, higher demands are being placed on their perception systems. Vibration sensors, in particular, are crucial for detecting contact and interaction between the humanoid robot and its environment, and are essential for its motion control and environmental adaptability.

[0003] Existing vibration sensing sensors mainly include piezoelectric, capacitive, and resistive types. While these sensors each have their advantages in terms of sensitivity, response speed, and durability, they still face some common challenges in practical applications. For example, many sensors require complex energy harvesting and conversion systems, which not only increases cost but also system complexity. Furthermore, the rigid structure of traditional sensors limits their application in wearable flexible devices for humanoid robots, which is particularly prominent in scenarios requiring close interaction between humanoid robots and humans.

[0004] Another challenge is that existing sensors are easily damaged by collisions or impacts, leading to the loss of monitoring data. This is unacceptable for applications requiring continuous monitoring, especially when humanoid robots are performing complex or dangerous tasks.

[0005] To address the aforementioned problems, this invention proposes a novel wearable flexible vibration sensing sensor for humanoid robots. Summary of the Invention

[0006] In view of this, the purpose of this invention is to provide a wearable flexible vibration sensing sensor for humanoid robots and its fabrication method, aiming to solve a series of challenges encountered in existing technologies for humanoid robot sensing systems. With the development of robotics technology, especially in industrial, service, and medical fields, the requirements for the intelligence level and interaction capabilities of humanoid robots are increasing. As a key component of the humanoid robot sensing system, the performance of the vibration sensing sensor directly affects the motion control and environmental adaptability of the humanoid robot.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: a wearable flexible vibration sensing sensor for humanoid robots, comprising an upper encapsulation layer, a moisture-absorbing layer, a hydrogel layer, a graphene layer, an electrode layer, a flexible circuit board, and a lower encapsulation layer;

[0008] The upper encapsulation layer is located on top of the sensor and is used to protect the internal structure of the sensor;

[0009] The moisture absorption layer is arranged below the upper packaging layer and is made of polyacrylic acid and a flexible non-woven fabric base to enhance the moisture absorption capacity in the environment.

[0010] The hydrogel layer is arranged below the moisture absorption layer and is made of a hydrogel solution and a flexible non-woven fabric base.

[0011] The graphene layer is arranged below the hydrogel layer and is made of a graphene solution and a flexible non-woven fabric base.

[0012] The electrode layer is arranged below the graphene layer and is used to collect the voltage generated by the ion migration between the hydrogel layer and the graphene layer.

[0013] The flexible circuit board is arranged below the electrode layer and is embedded with a signal amplification circuit and a wireless transmission module.

[0014] The lower packaging layer is arranged at the bottom of the sensor and is used to protect the internal structure of the sensor, and the area of the lower packaging layer is greater than or equal to the area of the hydrogel layer, the graphene layer, the electrode layer and the flexible circuit board to ensure that the entire sensor structure is completely packaged.

[0015] In a preferred embodiment, the upper packaging layer and the lower packaging layer are both made of polyimide PI film to improve the heat resistance and chemical resistance of the sensor.

[0016] In a preferred embodiment, the moisture absorption layer has a porous structure to improve its water absorption and water retention capacity.

[0017] In a preferred embodiment, the thickness of the hydrogel layer and the graphene layer is 100-200 microns to ensure the sensitivity and response speed of the sensor.

[0018] In a preferred embodiment, the electrode layer is made of conductive material by printing to ensure good electrical contact and signal transmission.

[0019] In a preferred embodiment, the overall thickness of the sensor is not more than 2 millimeters to ensure wearability and flexibility.

[0020] In a preferred embodiment, the signal amplification circuit and the wireless transmission module are integrated on the flexible circuit board layer to realize signal amplification and wireless transmission.

[0021] The application also provides a preparation method of a humanoid robot wearable flexible vibration sensing sensor, which comprises the following steps:

[0022] Step S1, forming the upper and lower packaging layers by cutting process using polyimide PI film;

[0023] Step S2, forming the moisture absorption layer by cutting process using polyacrylic acid and a flexible non-woven fabric base;

[0024] Step S3, immerse the non-woven fabric substrate into the polyacrylic hydrogel solution, and after drying, form a hydrogel layer;

[0025] Step S4, immerse the non-woven fabric substrate into the graphene dispersion solution, and after drying, form a graphene layer;

[0026] Step S5, print a metal electrode on the graphene layer to form an electrode layer;

[0027] Step S6, ensure that the electrodes on the flexible circuit board match the electrode layer to achieve electrical connection;

[0028] Step S7, stack and align the upper encapsulation layer, the moisture absorption layer, the hydrogel layer, the graphene layer, the electrode layer, and the flexible circuit board, and bond them together by heat pressing or adhesive to form a sensor main structure;

[0029] Step S8, bond the lower encapsulation layer with the bottom of the sensor main structure to completely encapsulate the sensor structure.

[0030] In a preferred embodiment, the step S3 is specifically:

[0031] Step S31, prepare the hydrogel dispersion solution to ensure that the polyacrylic acid is uniformly dispersed in the solution;

[0032] Step S32, slowly immerse the non-woven fabric substrate into the polyacrylic hydrogel solution preheated to 60°C for 3 minutes to ensure that the non-woven fabric is completely covered with the solution;

[0033] Step S33, take out the non-woven fabric substrate and control the ambient temperature at 25°C for 5 minutes to ensure that the solution is fully absorbed by the non-woven fabric;

[0034] Step S34, repeat steps S32 and S33 to enhance the thickness and uniformity of the hydrogel layer;

[0035] Step S35, naturally dry the treated non-woven fabric substrate in a well-ventilated environment, or dry it at 40°C for 1 hour to form a hydrogel layer;

[0036] In a preferred embodiment, the step S4 is specifically:

[0037] Step S41, prepare the graphene dispersion solution to ensure that the graphene is uniformly dispersed in the solution;

[0038] Step S42, immerse the non-woven fabric into the graphene dispersion solution for 5 minutes to ensure that the surface of the non-woven fabric is uniformly covered with the graphene solution;

[0039] Step S43, take out the non-woven fabric and control the ambient temperature at 25°C for 5 minutes to ensure that the graphene solution is fully absorbed by the non-woven fabric;

[0040] Step S44, repeat steps S42 and S43 to enhance the conductivity and uniformity of the graphene layer;

[0041] Step S45, dry the treated non-woven fabric in a well-ventilated environment naturally or at 40°C for 1 hour to form a graphene layer.

[0042] Compared with the prior art, the present application has the following beneficial effects:

[0043] 1. The sensor of the present application uses the principle of moisture power generation. The sensor generates voltage fluctuations when it vibrates, thereby achieving sensitive perception of vibration. This design directly uses the moisture in the environment as an energy source, eliminating the need for an external power source required by traditional sensors, simplifying the energy collection and conversion system, thereby reducing costs and improving system reliability.

[0044] 2. The sensor of the present application has good scalability and customizability. The size, shape and material composition of the sensor can be adjusted according to different application requirements to meet the monitoring requirements in specific scenarios. This flexibility enables the sensor to adapt to diverse humanoid robot design and application requirements.

[0045] 3. The sensor of the present application has convenient maintenance. The modular design allows quick replacement of sensor components when needed, reducing maintenance costs and time. At the same time, to improve monitoring accuracy and comprehensiveness, the sensor system of the present application can also be integrated with other types of sensors to realize multi-sensor data fusion and provide more comprehensive environmental information. This multi-sensor fusion technology uses multiple sensors to obtain comprehensive and complete information about objects and the environment, greatly enhancing the perception ability and decision-making efficiency of humanoid robots.

[0046] 4. The sensor of the present application is suitable for high-sensitivity and fast-response application scenarios such as humanoid robot balance control, precision operation and environmental interaction. The sensor design allows it to accurately capture vibrations in all directions, ensuring accurate monitoring of robot movement. This omnidirectional vibration perception capability enables the robot to more accurately perceive and adapt to its operating environment, thereby exhibiting higher precision and reliability in complex motion execution and interaction response. BRIEF DESCRIPTION OF DRAWINGS

[0047] Figure 1 is a schematic diagram of the overall structure of the wearable flexible vibration perception sensor of the humanoid robot of the present application;

[0048] Figure 2 is an exploded view of the wearable flexible vibration perception sensor of the humanoid robot of the present application;

[0049] Figure 3 is a cross-sectional view of the wearable flexible vibration perception sensor of the humanoid robot of the present application;

[0050] Figure 4 is a three-view drawing of the humanoid robot wearable flexible vibration sensing sensor of the present invention;

[0051] Figure 5 is a moisture power generation component drawing of the humanoid robot wearable flexible vibration sensing sensor of the present invention;

[0052] Figure 6 is a moisture absorption layer component drawing of the humanoid robot wearable flexible vibration sensing sensor of the present invention;

[0053] Figure 7 is a flexible circuit board signal amplification circuit schematic diagram of the humanoid robot wearable flexible vibration sensing sensor of the present invention;

[0054] Figure 8 is a flexible circuit board structure schematic diagram of the humanoid robot wearable flexible vibration sensing sensor of the present invention;

[0055] Figure 9 is a packaging layer structure schematic diagram of the humanoid robot wearable flexible vibration sensing sensor of the present invention;

[0056] Figure 10 is a preparation flow chart of the humanoid robot wearable flexible vibration sensing sensor of the present invention;

[0057] Figure 11 is a working principle diagram of the humanoid robot wearable flexible vibration sensing sensor of the present invention;

[0058] Figure 12 is a still state result diagram of the humanoid robot wearable flexible vibration sensing sensor of the present invention;

[0059] Figure 13 is a motion state result diagram of the humanoid robot wearable flexible vibration sensing sensor of the present invention;

[0060] Figure 2 In the figure: 1 - upper packaging layer, 2 - moisture absorption layer, 3 - hydrogel layer, 4 - graphene layer, 5 - electrode layer, 6 - flexible circuit board, 7 - lower packaging layer. DETAILED DESCRIPTION

[0061] The present invention will be further described below in conjunction with the accompanying drawings and examples.

[0062] It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the present application. Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs.

[0063] It is to be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments consistent with the present application; as used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, steps, operations, elements, components, and / or groups thereof, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof.

[0064] A humanoid robot wearable flexible vibration sensing sensor, with reference to Figures 1-13 , comprising an upper packaging layer 1, a moisture absorption layer 2, a hydrogel layer 3, a graphene layer 4, an electrode layer 5, a flexible circuit board 6 and a lower packaging layer 7;

[0065] The upper packaging layer 1 is located at the top of the sensor, which is used to protect the internal structure of the sensor;

[0066] The moisture absorption layer 2 is arranged below the upper packaging layer 1, which is made of polyacrylic acid and flexible non-woven fabric base to enhance the ability to absorb moisture in the environment;

[0067] The hydrogel layer 3 is located below the moisture absorption layer 2, which is made of hydrogel solution and flexible non-woven fabric base;

[0068] The graphene layer 4 is located below the hydrogel layer 3, which is made of graphene solution and flexible non-woven fabric base;

[0069] The electrode layer 5 is arranged below the graphene layer 4, which is used to collect the voltage generated by the ion migration between the hydrogel layer and the graphene layer;

[0070] The flexible circuit board 6 is arranged below the electrode layer 5, which is embedded with signal amplification circuit and wireless transmission module;

[0071] The lower packaging layer 7 is located at the bottom of the sensor, which is used to protect the internal structure of the sensor, and its area is greater than or equal to the area of the hydrogel layer 3, the graphene layer 4, the electrode layer 5 and the flexible circuit board 6, to ensure that the entire sensor structure is completely packaged.

[0072] The upper packaging layer 1 and the lower packaging layer 7 are both made of polyimide PI film to improve the heat resistance and chemical resistance of the sensor.

[0073] The moisture absorption layer 2 has a porous structure to improve its water absorption and water retention capacity.

[0074] The thickness of the hydrogel layer 3 and the graphene layer 4 is 100-200 microns to ensure the sensitivity and response speed of the sensor.

[0075] The electrode layer 5 is printed with conductive material to ensure good electrical contact and signal transmission.

[0076] The overall thickness of the sensor is not more than 2mm to ensure wearability and flexibility.

[0077] The signal amplification circuit and wireless transmission module are integrated on a flexible circuit board layer to realize signal amplification and wireless transmission.

[0078] The application also provides a preparation method of a wearable flexible vibration sensing sensor for a humanoid robot, comprising the following steps:

[0079] Step S1, forming an upper packaging layer 1 and a lower packaging layer 7 by cutting process using a polyimide (PI) film;

[0080] Step S2, forming a moisture absorption layer 2 by cutting process using polyacrylic acid and a flexible non-woven fabric substrate;

[0081] Step S3, immersing the non-woven fabric substrate in a polyacrylic acid hydrogel solution, and forming a hydrogel layer 3 after drying;

[0082] Step S4, immersing the non-woven fabric substrate in a graphene dispersion solution, and forming a graphene layer 4 after drying;

[0083] Step S5, printing a metal electrode on the graphene layer to form an electrode layer 5;

[0084] Step S6, ensuring that the electrodes on the flexible circuit board 6 match the electrode layer 5 to realize electrical connection;

[0085] Step S7, laminating and aligning the upper packaging layer 1, the moisture absorption layer 2, the hydrogel layer 3, the graphene layer 4, the electrode layer 5 and the flexible circuit board 6, and forming a sensor main structure by heat pressing or adhesive bonding;

[0086] Step S8, bonding the lower packaging layer 7 with the bottom of the sensor main structure to completely encapsulate the sensor structure.

[0087] The step S3 specifically comprises:

[0088] Step S31, preparing a hydrogel dispersion solution to ensure uniform dispersion of polyacrylic acid in the solution;

[0089] Step S32, slowly immersing the non-woven fabric substrate in the polyacrylic acid hydrogel solution preheated to 60°C for 3 minutes to ensure that the non-woven fabric is completely covered with the solution;

[0090] Step S33, taking out the non-woven fabric substrate and placing it in an environment with a temperature of 25°C for 5 minutes to ensure that the solution is fully absorbed by the non-woven fabric;

[0091] Step S34, repeating steps S32 and S33 to enhance the thickness and uniformity of the hydrogel layer;

[0092] Step S35, dry the treated non-woven fabric under good ventilation or at 40°C for 1 hour to form the hydrogel layer 3;

[0093] The step S4 is specifically:

[0094] Step S41, prepare a graphene dispersion solution to ensure uniform dispersion of graphene in the solution;

[0095] Step S42, immerse the non-woven fabric in the graphene dispersion solution for 5 minutes to ensure uniform coverage of the graphene solution on the surface of the non-woven fabric;

[0096] Step S43, take out the non-woven fabric and control the ambient temperature at 25°C for 5 minutes to ensure that the graphene solution is fully absorbed by the non-woven fabric;

[0097] Step S44, repeat steps S42 and S43 to enhance the conductivity and uniformity of the graphene layer;

[0098] Step S45, dry the treated non-woven fabric under good ventilation or at 40°C for 1 hour to form the graphene layer 4.

[0099] Specifically, by constructing an asymmetric structure inside the material, i.e., the hydrogel layer 3 and the graphene layer 4, this structural design causes the functional groups or water content inside the hydrogel layer 3 to exhibit a gradient distribution, thereby maintaining a constant voltage at the interface between the hydrogel layer 3 and the graphene layer 4 without external force.

[0100] When the sensor is subjected to vibrations caused by the movement of the humanoid robot, the micro-environment changes induced by the vibrations temporarily disturb the ion migration balance in the hydrogel layer. Specifically, the ion concentration gradient between the hydrogel layer 3 and the graphene layer 4 promotes the formation of a stable voltage at the two interfaces. Due to the larger size of anions, which are bound to conjugated structures or long chains and cannot freely migrate, cations migrate from high-concentration areas to low-concentration areas under the action of an electric field, forming a gradient structure of cations.

[0101] Under the continuous action of the ion concentration gradient, the migration of cations produces a stable voltage output. When the sensor encounters external vibrations, the ion migration pattern temporarily changes due to the vibrations, causing a temporary disturbance in the distribution of cations, which in turn causes voltage fluctuations. This transient voltage fluctuation directly reflects the intensity and frequency of the vibrations.

[0102] When the vibrations stop, the ion migration pattern in the hydrogel layer 3 gradually returns to equilibrium over time, and the cations redistribute under the electric field force generated by the anions, returning to their original stable distribution state. The flexible circuit board 6 is responsible for collecting these voltage changes, converting mechanical vibrations into measurable electrical signals, and achieving sensitive perception of vibrations.

[0103] The working process of the sensor is as follows:

[0104] Step A1: Sensor Installation: According to the specific application scenarios and needs of humanoid robots, appropriate installation locations are selected, usually at key motion joints or areas requiring vibration monitoring. The sensor is fixed to the surface of the humanoid robot, ensuring that it does not shift or fall off during the movement of the humanoid robot.

[0105] Step A2: Sensor Activation: After installation, the sensor is exposed to the environment, naturally absorbing moisture from the surroundings. This step is crucial for activating the moisture power generation unit in the sensor, as the presence of moisture is a prerequisite for generating electrical energy. When the sensor absorbs sufficient moisture, the internal voltage will gradually stabilize.

[0106] Step A3: Vibration Signal Conversion: When the humanoid robot moves, the sensor monitors and captures the vibrations caused by the movement in real time. These vibrations are converted into voltage changes through the interaction of the hydrogel layer and the graphene layer. The graphene layer enhances the sensitivity of the sensor, ensuring accurate capture of vibration signals.

[0107] Step A4: Data Recording and Processing: The captured electrical signals are amplified by the built-in circuit system and converted into digital signals, which are then stored in the sensor data processing module. These data can be transmitted to the robot control system in real time or saved for subsequent analysis.

[0108] Step A5: Sensor Standby and Maintenance: When the humanoid robot stops running, i.e., the humanoid robot no longer generates vibrations or movements, the sensor will automatically enter a low-power standby mode. In this mode, the sensor energy consumption is minimized to ensure that the sensor can save energy to the maximum extent during inactivity.

[0109] In practical applications, the sensor of the present application can be seamlessly integrated into the humanoid robot control system. The sensor transmits the collected vibration data to the central processing unit in real time through the built-in data processing module. These data are then used for robot motion analysis and environmental adaptability evaluation. In addition, the sensor output signal can be fused with other perception modules on the robot, such as visual, tactile, or sound sensor data, thereby providing a comprehensive environmental perception capability and enhancing the robot's understanding and response ability to the surrounding environment.

[0110] Through the above implementation, the sensor of the present application realizes high sensitivity vibration sensing. When the humanoid robot moves, the sensor can accurately capture the voltage changes caused by the movement and convert these changes into electrical signals that can be used by the robot control system. This self-powered design eliminates the need for external power supply, thereby improving the practicality and reliability of the sensor. At the same time, the modular design of the sensor simplifies the maintenance and replacement process, reduces long-term operating costs, and prolongs the service life.

Claims

1. A wearable flexible vibration sensing sensor for humanoid robots, characterized in that: It includes an upper encapsulation layer, a moisture-absorbing layer, a hydrogel layer, a graphene layer, an electrode layer, a flexible circuit board, and a lower encapsulation layer; The upper encapsulation layer is located on top of the sensor and is used to protect the internal structure of the sensor; The moisture-absorbing layer is located below the upper encapsulation layer and is made of polyacrylic acid and a flexible non-woven fabric base to enhance the ability to absorb moisture from the environment. The hydrogel layer is located below the moisture-absorbing layer and is made of a hydrogel solution and a flexible non-woven fabric substrate; The graphene layer is located below the hydrogel layer and is made of graphene solution and flexible nonwoven fabric substrate; The electrode layer is disposed below the graphene layer and is used to collect the voltage generated by ion migration between the hydrogel layer and the graphene layer. The flexible circuit board is located below the electrode layer and has embedded signal amplification circuit and wireless transmission module. The lower encapsulation layer is located at the bottom of the sensor and is used to protect the internal structure of the sensor. Its area is greater than or equal to the area of ​​the hydrogel layer, graphene layer, electrode layer, and flexible circuit board to ensure that the entire sensor structure is completely encapsulated. By constructing an asymmetric structure within the material, namely a hydrogel layer and a graphene layer, the functional groups or water content within the hydrogel layer are made to exhibit a gradient distribution, thereby maintaining a constant voltage at the interface between the hydrogel layer and the graphene layer when no external force is applied. When the sensor vibrates due to the movement of the humanoid robot, the resulting microenvironmental changes instantaneously disturb the ion migration equilibrium in the hydrogel layer. The ion concentration gradient between the hydrogel layer and the graphene layer facilitates the formation of a stable voltage at the interface. Due to the large size of anions, they are bound to conjugated structures or long chains and cannot migrate freely, while cations migrate from high-concentration regions to low-concentration regions under the influence of the electric field, forming a cation gradient structure. Under the continuous influence of the ion concentration gradient, cation migration generates a stable voltage output; when the sensor encounters external vibration, the instantaneous change in the ion migration mode caused by the vibration leads to a brief disturbance in the cation distribution, which in turn causes voltage fluctuations. When the vibration stops, the ion migration pattern within the hydrogel layer gradually returns to equilibrium over time. The cations are redistributed under the influence of the electric field generated by the anions, returning to their original stable distribution state. The flexible circuit board is responsible for collecting these voltage changes, converting the mechanical vibration into a measurable electrical signal, and realizing sensitive detection of the vibration.

2. The wearable flexible vibration sensing sensor for humanoid robots according to claim 1, characterized in that: Both the upper and lower encapsulation layers are made of polyimide (PI) film to improve the sensor's heat resistance and chemical resistance.

3. The wearable flexible vibration sensing sensor for humanoid robots according to claim 1, characterized in that: The moisture-absorbing layer has a porous structure to improve its water absorption and retention capacity.

4. The wearable flexible vibration sensing sensor for humanoid robots according to claim 1, characterized in that: The thickness of the hydrogel layer and graphene layer is 100-200 micrometers to ensure the sensor's sensitivity and response speed.

5. The wearable flexible vibration sensing sensor for humanoid robots according to claim 1, characterized in that: The electrode layer is printed with conductive material to ensure good electrical contact and signal transmission.

6. The wearable flexible vibration sensing sensor for humanoid robots according to claim 1, characterized in that: The overall thickness of the sensor does not exceed 2 millimeters to ensure wearability and flexibility.

7. A wearable flexible vibration sensing sensor for humanoid robots according to claim 1, characterized in that: The signal amplification circuit and wireless transmission module are integrated on a flexible circuit board layer to achieve signal amplification and wireless transmission.

8. A method for fabricating a wearable flexible vibration sensing sensor for a humanoid robot according to any one of claims 1-7, characterized in that... Includes the following steps: Step S1: Use polyimide (PI) film to form upper and lower encapsulation layers through a cutting process; Step S2: A moisture-absorbing layer is formed by cutting a polyacrylic acid and flexible non-woven fabric substrate. Step S3: Immerse the nonwoven fabric substrate in the polyacrylic acid hydrogel solution and dry it to form a hydrogel layer; Step S4: Immerse the nonwoven fabric substrate in the graphene dispersion and dry it to form a graphene layer; Step S5: Print metal electrodes on the graphene layer to form an electrode layer; Step S6: Ensure that the electrodes on the flexible circuit board match the electrode layer to achieve electrical connection; Step S7: Stack and align the encapsulation layer, moisture-absorbing layer, hydrogel layer, graphene layer, electrode layer and flexible circuit board, and bond them together by hot pressing or adhesive to form the main structure of the sensor; Step S8: Adhere the lower encapsulation layer to the bottom of the sensor body structure to completely encapsulate the sensor structure.

9. The method for fabricating a wearable flexible vibration sensing sensor for a humanoid robot according to claim 8, characterized in that: Step S3 specifically involves: Step S31: Prepare the hydrogel dispersion to ensure that the polyacrylic acid is uniformly dispersed in the solution; Step S32: Slowly immerse the nonwoven fabric substrate into a preheated 60°C polyacrylic acid hydrogel solution for 3 minutes to ensure that the nonwoven fabric is completely covered by the solution. Step S33: Take out the nonwoven fabric substrate and let it stand at 25°C for 5 minutes to ensure that the solution is fully absorbed by the nonwoven fabric. Step S34: Repeat steps S32 and S33 to enhance the thickness and uniformity of the hydrogel layer; Step S35: Allow the treated nonwoven fabric substrate to air dry naturally in a well-ventilated environment, or dry it at 40°C for 1 hour to form a hydrogel layer.

10. The method for fabricating a wearable flexible vibration sensing sensor for a humanoid robot according to claim 8, characterized in that: Step S4 specifically involves: Step S41: Prepare a graphene dispersion to ensure that the graphene is uniformly dispersed in the solution. Step S42: Immerse the nonwoven fabric in the graphene dispersion for 5 minutes to ensure that the surface of the nonwoven fabric is uniformly covered with the graphene solution. Step S43: Take out the non-woven fabric and let it stand at 25°C for 5 minutes to ensure that the graphene solution is fully absorbed by the non-woven fabric. Step S44: Repeat steps S42 and S43 to enhance the conductivity and uniformity of the graphene layer. Step S45: Allow the treated nonwoven fabric to air dry naturally in a well-ventilated environment, or dry it at 40°C for 1 hour to form a graphene layer.

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