A robot electronic skin application of a touch chip and nanosilver wire tactile sensing array

Abstract

The application discloses a robot electronic skin with a touch chip and a nano silver wire tactile sensing array, which comprises a silica gel body, a sensing module, a control module, an interaction module and a power supply module; the silica gel body is made of a flexible material and is provided with a flexible framework; the sensing module adopts a nano silver wire flexible tactile sensing array and a touch chip; the sensing array comprises a conductive layer, an insulating layer and a shielding electrode layer; the touch chip collects capacitance change signals or resistance change signals of each sensing unit through a multi-channel synchronous sampling interface and outputs digitized signals; the control module generates a pressure detection value according to the amplitude of the digitized signals, generates a contact position coordinate according to the signal distribution, identifies a motion type according to the time change mode of the pressure and the coordinate, and generates a driving control instruction; and the interaction module adjusts the surface temperature of the silica gel body, outputs a voice signal and drives a posture motion based on the driving control instruction.

Description

Technical Field

[0001] This application relates to the field of intelligent interactive device technology, specifically to a robotic electronic skin consisting of a touch chip and a nano-silver wire tactile sensor array, which is suitable for scenarios such as emotional companion robots, medical rehabilitation assistive robots, humanoid robots and intelligent prostheses, and achieves high-precision, high-response tactile perception and interactive feedback. Background Technology

[0002] With the rapid development of intelligent robot technology, robotic electronic skin, as a core component for human-computer interaction and environmental perception, directly determines the robot's interactive experience and operational precision through its tactile sensing capabilities. Currently, the field of robotic electronic skin mainly faces the following technical shortcomings: First, the tactile sensitivity is low. Most existing electronic skins use traditional rigid tactile sensors or ordinary flexible sensors, whose sensitivity is usually only at the level of a few kPa. They cannot effectively capture subtle contact actions such as stroking or fingertip touches, and the pressure detection accuracy is insufficient, making it difficult to meet the needs of refined tactile perception.

[0003] Second, the response speed is slow. Existing flexible tactile sensors have long signal acquisition and processing links, resulting in significant time delays. The response time is usually over 50ms, which makes it impossible to achieve real-time tactile feedback and seriously affects the real-time performance and smoothness of robot-environment interaction.

[0004] Third, poor flexibility and adaptability. Existing electronic skin sensors generally have low stretchability (usually below 10%) and insufficient bending resistance (bending life is usually less than 10,000 cycles), making it difficult to adapt to various posture changes such as robot joint bending and skin stretching. After long-term use, problems such as sensor breakage and signal failure are likely to occur.

[0005] Fourth, it has weak anti-interference capabilities. Changes in ambient temperature and humidity, as well as electromagnetic interference generated by the robot's internal motor drives and communication modules, can easily cause sensor signals to drift, affecting the accuracy and stability of tactile perception. Current technologies lack effective temperature compensation and electromagnetic shielding methods.

[0006] Fifth, the core components suffer from poor compatibility and high cost. Existing flexible tactile sensors mostly use materials such as carbon nanotubes and graphene, but their fabrication processes are complex and costly. Some sensors using silver nanowires suffer from problems such as the silver wires being prone to breakage and insufficient adhesion to flexible substrates. At the same time, existing touch acquisition solutions mostly use general-purpose touch chips, which have weak multi-channel acquisition capabilities and low signal-to-noise ratios, making it difficult to meet the engineering requirements for tactile perception in multiple areas of the robot's entire body.

[0007] Furthermore, sensors using carbon nanotubes or graphene as sensing materials typically involve chemical vapor deposition or complex photolithography processes, resulting in high equipment investment, long production cycles, and low yields, making large-area, mass production difficult. Sensors using traditional silver nanowires, while exhibiting excellent conductivity, suffer from insufficient adhesion to flexible substrates, leading to wire peeling or breakage after thousands of bends and sensor failure. Existing flexible tactile sensors primarily utilize discrete component-based analog front-end circuits for signal acquisition, resulting in limited channel counts (typically no more than 16 channels), low integration, and large printed circuit board areas, failing to meet the miniaturization and integration requirements of full-body distributed tactile sensing in robots. Summary of the Invention

[0008] This application aims to overcome the technical defects of existing robotic electronic skin in terms of low sensitivity, response delay, poor flexibility and adaptability, weak anti-interference ability and high engineering cost, and provides a robotic electronic skin with a touch chip and a nano-silver wire touch sensing array.

[0009] To achieve the above objectives, this application adopts the following technical solution: A robotic electronic skin with a touch chip and a nano-silver wire tactile sensing array includes a silicone body, a sensing module, a control module, an interaction module, and a power supply module. The sensing module, control module, interaction module, and power supply module are respectively disposed inside the silicone body, and the modules are electrically connected to each other. The silicone body is made of flexible material and has an internal flexible skeleton to support each module and deform with the silicone body. The sensing module includes a flexible tactile sensor array and a touch chip. The flexible tactile sensor array is a capacitive or piezoresistive architecture, comprising a conductive layer, an insulating layer, and a shielding electrode layer. The conductive layer is composed of silver nanowires. The insulating layer is disposed between the conductive layer and the shielding electrode layer for electrical isolation between them. The shielding electrode layer is disposed on the side of the insulating layer opposite to the conductive layer to provide a reference ground for the conductive layer to suppress electromagnetic interference. The flexible tactile sensor array is distributed in multiple areas of the silicone body, each area containing multiple sensing units. Each sensing unit has a corresponding conductive layer, insulating layer, and shielding electrode layer. The touch chip has a multi-channel synchronous sampling interface. Each sampling channel is connected to the conductive layer of each sensing unit to collect the capacitance change signal or resistance change signal generated by each conductive layer under external pressure. The capacitance change signal or resistance change signal is filtered and converted from analog to digital before being output as a digital signal. The control module includes a microcontroller. The signal input terminal of the microcontroller is connected to the signal output terminal of the touch chip. It is used to receive digital signals and run haptic algorithms. The haptic algorithm generates pressure detection values ​​for each sensing unit based on the amplitude of the digital signals from each sensing unit, generates contact position coordinates based on the distribution of the digital signals from each sensing unit, and identifies the action type based on the change pattern of each pressure detection value and contact position coordinate over time. The microcontroller is also used to generate drive control commands based on the pressure detection values, contact position coordinates, and action type. The control output terminal of the microcontroller is connected to the control input terminal of the interaction module. The interaction module includes a heating unit, a voice unit, and a posture driving unit. The heating unit is used to adjust the surface temperature of the silicone body based on the driving control command. The voice unit is used to output a voice signal based on the driving control command. The posture driving unit is used to drive at least a part of the silicone body to perform posture actions based on the driving control command. The power supply module includes a rechargeable battery, a voltage conversion unit, and a voltage regulator unit. The output terminal of the rechargeable battery is connected to the input terminal of the voltage conversion unit, the output terminal of the voltage conversion unit is connected to the input terminal of the voltage regulator unit, and the output terminal of the voltage regulator unit outputs the operating voltage to the sensing module, the control module, and the interaction module.

[0010] Furthermore, the flexible tactile sensing array is a flexible tactile sensing array fabricated using the following processes: S1. A primer is applied to the surface of the silicone body, and the primer cures to form micro-textures; S2. Using slot coating or screen printing, the nano-silver wire ink is coated onto the silicone surface treated in step S1, and the coated nano-silver wire ink is dried at 80°C. The dried nano-silver wire ink forms a conductive layer. S3. Coat the surface of the conductive layer with an ultrathin silicone layer as an insulating layer, and lay a shielding electrode layer below the insulating layer; S4. A flexible printed circuit board is used to connect the conductive layer to the sensing channel of the touch chip; S5. The flexible tactile sensor array formed after steps S1 to S4 is vacuum potted to achieve a waterproof rating of IP67.

[0011] Furthermore, the core circuitry of the touch chip includes a power supply circuit, a sensing channel circuit, a communication circuit, and an anti-interference circuit. The power supply circuit includes a power supply terminal, a ground terminal, and a decoupling capacitor. The power supply terminal is connected to the operating voltage output of the voltage regulator unit, the ground terminal is connected to the system ground, and the decoupling capacitor is connected between the power supply terminal and the ground terminal. The sensing channel circuit includes multiple current-limiting resistors. One end of each current-limiting resistor is connected to the corresponding sensing channel pin of the touch chip, and the other end of each current-limiting resistor is connected to the conductive layer of the corresponding sensing unit. The communication circuit uses I 2 The C-bus or SPI bus interface connects the data pins and clock pins of the communication circuit to the corresponding general-purpose input / output pins of the microcontroller, and the data pins and clock pins are connected to the operating voltage through pull-up resistors. The anti-interference circuit includes a reset pin and an interrupt pin. The reset pin is connected to the operating voltage through a reset resistor, and the interrupt pin is connected to the interrupt input terminal of the microcontroller. The printed circuit board of the core circuit adopts a layered layout. The analog ground corresponding to the ground terminal of the sensing channel circuit is isolated from the digital ground corresponding to the communication circuit and the microcontroller. The wiring area of ​​the sensing channel circuit and the wiring area of ​​the attitude drive unit are spaced apart from each other.

[0012] Furthermore, the haptic algorithm includes pressure grading algorithm, multi-point positioning algorithm, temperature compensation algorithm, and drift correction algorithm; The pressure grading algorithm is used to generate pressure detection values ​​for each sensing unit based on the amplitude of the digital signal of each sensing unit, and compare each pressure detection value with a preset three-level pressure threshold to determine the pressure level of each sensing unit. The three-level pressure thresholds are a first pressure range of 0.1N to 1N, a second pressure range of greater than 1N and less than or equal to 5N, and a third pressure range of greater than 5N. The multi-point positioning algorithm is used to calculate the coordinate information of the contact position based on the amplitude and distribution of the digital signals of each sensing unit using the centroid method. Temperature compensation algorithms are used to calibrate digital signals in real time based on ambient temperature; The drift correction algorithm is used to automatically calibrate the baseline value of the digital signal of each sensing unit at a preset time interval in order to eliminate the drift of each digital signal.

[0013] Furthermore, the diameter of the silver nanowires is 20nm to 50nm and the length is 30μm to 50μm; an elastic polymer is also added to the conductive layer, the conductive layer has a bending resistance of more than or equal to 100,000 times and an elongation of more than or equal to 30%; the total number of sensing units in the flexible tactile sensing array is 32 to 40.

[0014] Furthermore, the silicone body is made of medical-grade platinum silicone; the heating unit maintains the surface temperature of the silicone body at 36℃~37℃.

[0015] Furthermore, the silver nanowires were prepared by reacting silver nitrate as the silver source, polyvinylpyrrolidone as the inducing agent, and copper chloride as the inhibitor in a polyol solvent system, and the aspect ratio of the silver nanowires was 1500-1921.

[0016] Furthermore, in the sensing channel circuit, the resistance of each current-limiting resistor is 1MΩ, and each current-limiting resistor is connected in series between the corresponding sensing channel pin and the conductive layer of the corresponding sensing unit; the capacitance of the decoupling capacitor is 0.1μF; the resistance of the pull-up resistor is 4.7kΩ; and the resistance of the reset resistor is 10kΩ.

[0017] Furthermore, in the anti-interference circuit, an isolation strip is provided between the analog ground plane corresponding to the sensing channel circuit and the digital ground plane corresponding to the communication circuit and the microcontroller on the printed circuit board, and the spacing between the wiring area of ​​the sensing channel circuit and the wiring area of ​​the attitude drive unit is greater than or equal to 5mm.

[0018] Furthermore, the silicone body is divided into multiple sensing zones, including a head area, a face area, a neck area, a shoulder area, a chest area, an arm area, a waist area, and a leg area. Each sensing zone is equipped with a corresponding number of sensing units of a flexible tactile sensing array. The number of sensing units in the head area, face area, neck area, shoulder area, chest area, arm area, waist area, and leg area are 4, 6, 2, 4, 6, 8, 4, and 8, respectively.

[0019] In the above technical solution, the touch chip can be the CS8056 high-integration capacitive multi-touch control IC, as an example, but not limited to this model. This chip operates at 3.3V, has a built-in 16-bit analog-to-digital converter, supports up to 40 channels of simultaneous sampling, and has a signal-to-noise ratio of no less than 60dB. (The last sentence appears to be incomplete and possibly refers to I / O.) 2 The microcontroller communicates with the control module via a C-interface or SPI interface. It can be an STM32 series MCU, such as, but not limited to, STM32F103C8T6 or STM32F407VET6. In the fabrication of the flexible tactile sensor array using silver nanowires, the primer curing temperature is 80℃, and the curing time is 30 minutes; the concentration of the silver nanowire ink is 2mg / ml~3mg / ml, and the drying time is 15~20 minutes; the thickness of the ultrathin silicone layer is 0.1mm. Vacuum potting can be performed using medical-grade potting compound, with a vacuum level not lower than -0.08MPa. The curing temperature after potting is 60℃~80℃, and the curing time is 2~4 hours.

[0020] Compared with the prior art, this application has the following advantages: 1. High tactile sensitivity and fast response speed: By using a flexible tactile sensor array of silver nanowires as the sensing core, the conductive network of silver nanowires has extremely high resistance / capacitance response sensitivity to changes in external pressure, with a sensitivity level of up to 0.1kPa, which can effectively capture subtle contact actions such as stroking and fingertip touch; combined with the multi-channel synchronous sampling and fast analog-to-digital conversion function of the touch chip (16-bit ADC, signal-to-noise ratio ≥60dB), the signal acquisition and processing link response time is less than 20ms, realizing real-time tactile feedback and solving the problems of dull and delayed tactile perception in existing products.

[0021] 2. Excellent flexibility and durability: By adding an elastic polymer to the conductive layer and optimizing the composite formula of silver nanowires and silicone, the tensile strength of the silver nanowire conductive layer reaches over 30%, and the bending resistance exceeds 100,000 cycles. This allows it to perfectly adapt to the bending and stretching deformation of the silicone body under various robot joint postures. The IP67 waterproof rating is achieved through vacuum potting, giving the electronic skin cleanable and durable engineered characteristics, solving the problems of easy breakage and poor durability of existing sensors.

[0022] 3. Strong anti-interference capability and stable signal: By adopting a sandwich-style sensing structure of conductive layer-insulating layer-shielding electrode layer, the shielding electrode layer provides a stable reference ground potential for the conductive layer, effectively suppressing external electromagnetic interference. Combined with the isolation layout of analog and digital ground on the printed circuit board, the physical spacing (≥5mm) between the sensing channel wiring area and the attitude drive unit wiring area, and the real-time calibration of temperature drift by the temperature compensation algorithm (based on the compensation formula of the resistance temperature coefficient of silver nanowires), and the periodic correction of baseline drift by the drift correction algorithm (automatic resampling and updating of the baseline in continuous idle state), the accuracy and stability of the tactile sensing signal are ensured from the three levels of structure, layout and algorithm, solving the problems of easy signal drift and weak anti-interference capability of existing products.

[0023] 4. Good compatibility and controllable cost: By adopting an optimized matching scheme of a highly integrated, low-power dedicated touch chip and a nano-silver wire sensor, the circuit design is simplified; by using domestically produced nano-silver wire materials and optimizing the coating thickness and preparation process (slit coating or screen printing), the material and manufacturing costs are reduced, making it easier for mass production and solving the problems of poor compatibility of core components and high engineering costs in existing products.

[0024] 5. Excellent interactive experience and wide range of applications: By integrating a heating unit (simulating human body temperature at 36℃~37℃), a voice unit (emotional voice response), and a posture-driven unit (posture and motion feedback), it achieves a multimodal tactile interactive experience; 32-40 sensing units throughout the body cover key areas such as the head, face, neck, shoulders, chest, arms, waist, and legs, making it widely applicable in fields such as emotional companion robots, medical rehabilitation assistive robots, humanoid robots, and intelligent prostheses. The power supply module has a standby time of over 72 hours, meeting daily usage needs. Attached Figure Description

[0025] Figure 1 This is a diagram of the overall system architecture of this application; Figure 2 This is a schematic diagram of the flexible tactile sensing array structure of the silver nanowires in this application; Figure 3 This is the core circuit diagram of the touch chip in this application; Figure 4 This is a schematic diagram of the partitioned arrangement of the silver nanowire sensing array in this application. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings. The described embodiments should not be regarded as limitations on this application. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0027] In the application scenarios of robotic electronic skin, the tactile perception system needs to simultaneously meet multiple requirements such as high sensitivity, fast response, flexible adaptation, and anti-interference. Taking emotional companion robots as an example, the robot needs to use electronic skin to sense the user's touch intensity (stroking, hugging, pressing), touch location (arm, chest, face, etc.), and touch action pattern (sliding, tapping, holding, etc.), and make corresponding emotional responses based on this—including adjusting the body surface temperature to simulate human body temperature, outputting voice responses, and performing posture actions.

[0028] In existing technologies, achieving tactile perception often faces a dilemma: rigid sensors, while providing stable signals, cannot adapt to flexible surfaces; while ordinary flexible sensors can deform, they suffer from low sensitivity and short lifespan. Furthermore, the motor drive module inside the robot generates strong electromagnetic interference, affecting the accuracy of tactile signal acquisition. This application addresses these technical contradictions by providing a robotic electronic skin solution that combines high sensitivity, rapid response, excellent flexibility, and strong anti-interference capabilities through synergistic innovation in four areas: material selection (silver nanowires), structural design (sandwich-style sensing layer), chip selection (dedicated touch chip), and system integration (perception-control-interaction closed loop).

[0029] Example 1: Overall Architecture of Robotic Electronic Skin This embodiment provides a robotic electronic skin consisting of a touch chip and a nano-silver wire tactile sensing array, including a silicone body 1, a sensing module, a control module 4, an interaction module 5, and a power supply module 6. The sensing module, control module 4, interaction module 5, and power supply module 6 are respectively disposed inside the silicone body 1, and the modules are electrically connected to each other through wires or flexible circuit boards.

[0030] The silicone body 1 is made of medical-grade platinum silicone with a thickness of 0.3mm to 0.8mm. It has a feel similar to human skin, is non-toxic, and anti-aging. The silicone body 1 has a flexible skeleton inside (not shown in the figure). This flexible skeleton is made of an elastic material with shape memory function, which is used to support each module and deform with the silicone body 1 to ensure that the electronic skin can maintain its structural integrity in various postures.

[0031] like Figure 1 As shown, the overall system architecture of the robot electronic skin in this application adopts a layered modular design. Figure 1 In this structure, the silicone body 1 serves as the underlying support structure, encasing all functional modules. The sensing module is located on the inner surface of the silicone body 1 and is electrically connected to the touch chip 3. The touch chip 3 communicates with the touch chip 3 via I... 2 The system communicates bidirectionally with the control module 4 via a C or SPI bus. The control module 4 connects to the control input of the interaction module 5 through its control output terminal, sending drive control commands to the interaction module 5. The voltage output terminal of the power supply module 6 is connected to the power input terminals of the sensing module (the power supply terminal of the touch chip 3), the control module 4, and the interaction module 5, respectively, providing operating voltage to each module.

[0032] Specifically, Figure 1 The signal flow between the modules is as follows: The flexible tactile sensor array 2 with silver nanowires in the sensing module generates capacitance or resistance change signals under external pressure. The touch chip 3 acquires these signals, performs filtering and analog-to-digital conversion, and then transmits the signals through I... 2 The C or SPI interface outputs digital signals to the control module 4; after running the haptic algorithm, the control module 4 generates drive control commands and sends them to the interaction module 5 through the control output terminal; the power supply module 6 supplies operating voltage to the sensing module, control module 4, and interaction module 5 respectively through the voltage output terminal. The connection relationships and signal flow between each module are shown in [the diagram]. Figure 1 Clearly marked in Chinese.

[0033] The sensing module includes a flexible tactile sensing array 2 and a touch chip 3. As an example, the touch chip 3 may be a CS8056 high-integration capacitive multi-touch control IC from Chipwise Microelectronics, but this application is not limited to this model. This chip operates at 3.3V, has a built-in 16-bit analog-to-digital converter, supports up to 40 channels of simultaneous sampling, and has a signal-to-noise ratio of no less than 60dB. The chip connects via I... 2 The C bus interface (e.g., device address 0x22) communicates with control module 4, outputting a filtered and analog-to-digital converted 16-bit digital signal.

[0034] like Figure 2 As shown, the flexible tactile sensing array 2 is a capacitive architecture (or piezoresistive architecture) employing a sandwich-style layered structure, including: a platinum silicone outer layer 24, a silver nanowire conductive layer 21, a flexible insulating layer 22, and a shielding ground electrode 23. The silver nanowire conductive layer 21 is composed of silver nanowires with a diameter of 20nm–50nm and a length of 30μm–50μm, forming a flexible conductive network. The flexible insulating layer 22, made of ultra-thin silicone material with a thickness of 0.1mm, is disposed between the silver nanowire conductive layer 21 and the shielding ground electrode 23, and serves to electrically isolate the conductive layer 21 from the shielding electrode layer 23. The shielding electrode layer 23, made of copper foil with a thickness of 0.05mm–0.1mm, is disposed on the side of the flexible insulating layer 22 opposite to the conductive layer 21 (i.e., below the insulating layer), and provides a stable reference ground potential for the conductive layer 21 to suppress electromagnetic interference.

[0035] The flexible tactile sensor array 2 is distributed in multiple areas of the silicone body 1 (e.g., Figure 4 As shown, each region contains multiple sensing units. Each sensing unit has a corresponding silver nanowire conductive layer 21, a flexible insulating layer 22, and a shielded ground electrode 23. Each sampling channel of the touch chip 3 is connected to the conductive layer 21 of each sensing unit through a flexible printed circuit board. This channel is used to collect the capacitance change signal (capacitive architecture) or resistance change signal (piezoresistive architecture) generated by each conductive layer 21 under external pressure. The collected signals are then filtered and converted from analog to digital before being output as digital signals.

[0036] Control module 4 includes a microcontroller. As an example, the microcontroller can be an STM32 series MCU, such as, but not limited to, the STM32F103C8T6 or STM32F407VET6. The microcontroller's signal input terminals (such as I...) 2The SDA / SCL pins of the C interface or the corresponding pins of the SPI interface are connected to the signal output terminal of the touch chip 3 to receive digital signals and run the haptic algorithm. The specific processing flow of the haptic algorithm is as follows: First, pressure detection values ​​of each sensing unit are generated according to the amplitude of the digital signals of each sensing unit—the larger the amplitude, the greater the pressure borne by the sensing unit; second, contact position coordinates are generated according to the distribution of the digital signals of each sensing unit—the centroid position of the contact area is calculated through the spatial distribution of multi-channel signals; then, the action type is identified according to the change pattern of each pressure detection value and contact position coordinate over time—for example, a rapid increase in pressure followed by holding is identified as "pressing," and continuous migration of pressure between adjacent sensing units is identified as "sliding." The microcontroller is also used to generate drive control commands based on the pressure detection values, contact position coordinates, and action type. The control output terminal of the microcontroller is connected to the control input terminal of the interaction module 5.

[0037] The interaction module 5 includes a heating unit, a voice unit, and a posture driving unit. The heating unit can be a PI heating element (polyimide film heating element) disposed inside the silicone body 1. It is used to adjust the surface temperature of the silicone body 1 based on drive control commands, maintaining the surface temperature at 36℃~37℃ to simulate human body temperature. The voice unit can be a voice synthesis chip, such as, but not limited to, the SYN6288 or WT588D type voice chip, used to output voice signals based on drive control commands—for example, outputting a gentle greeting when a "touch" action is detected, and outputting a warm comforting word when a "hug" action is detected. The posture driving unit can be a small servo motor disposed at the joint positions of the silicone body 1 (such as the neck, shoulder, arm, etc.), used to drive at least a part of the silicone body 1 to perform posture actions based on drive control commands—for example, driving the arm to perform a closing action when receiving a "hug" command, and driving the head to perform a rotation action when receiving a "press" command.

[0038] The power supply module 6 includes a rechargeable battery, a voltage conversion unit, and a voltage regulator unit. The rechargeable battery can be an 18650 or 21700 lithium battery, outputting an initial voltage of 3.7V (single cell) or 7.4V (two cells in series). The output of the rechargeable battery is connected to the input of the voltage conversion unit, which boosts the battery voltage to an intermediate 5V. The output of the voltage conversion unit is connected to the input of the voltage regulator unit, which can be an LDO regulator (e.g., but not limited to, AMS1117) to regulate the 5V voltage to a 3.3V operating voltage. The voltage regulator unit outputs the 3.3V operating voltage to the sensing module (touch chip 3), control module 4, and interaction module 5, providing a stable power supply for each module. In low-power management mode, the power supply module 6 can achieve a standby time of over 72 hours.

[0039] Example 2: Fabrication process of flexible tactile sensing array In this embodiment, the flexible tactile sensing array 2 is a flexible tactile sensing array manufactured by the following process: Step S1 (Substrate Pretreatment): Apply a primer (such as a silane coupling agent primer) to the surface of the silicone substrate 1, with a coating thickness of 5μm to 10μm. Place the silicone substrate 1 with the primer applied in an oven at 80℃ for 30 minutes to cure. After the primer cures, a micro-rough textured structure is formed on the silicone surface. This micro-texture can significantly enhance the adhesion between the subsequent conductive layer 21 of silver nanowires and the silicone substrate.

[0040] Step S2 (Silver Nanowire Coating): Using slot coating or screen printing, uniformly coat the silver nanowire ink with a concentration of 2mg / ml to 3mg / ml onto the silicone surface treated in Step S1 (i.e., the silicone surface with microtextured structure). After coating, dry the coated silver nanowire ink at 80℃ for 15 to 20 minutes. During the drying process, the solvent in the silver nanowire ink evaporates, and the silver nanowires interlock to form a continuous conductive network. The dried silver nanowire ink forms the silver nanowire conductive layer 21.

[0041] Step S3 (Insulation and Shielding): A thin layer of silicone is coated onto the surface of the conductive layer 21 of the silver nanowire as a flexible insulating layer 22. The thickness of the thin silicone layer is 0.1 mm. It is coated by spin coating or spraying and then cured at 60°C for 1 hour. Below the flexible insulating layer 22 (i.e., on the side opposite to the conductive layer 21), a shielding electrode layer 23 is laid. The shielding electrode layer 23 is made of copper foil and is formed by bonding with conductive adhesive or sputtering. The thickness is 0.05 mm to 0.1 mm.

[0042] Step S4 (Electrode Lead-out): A flexible printed circuit board is used to connect the conductive layer 21 of the silver nanowires to the sensing channel of the touch chip 3. Specifically, silver paste pads are provided at the edge of the conductive layer 21 of the silver nanowires. One end of the flexible printed circuit board is pressed or soldered to the silver paste pads using anisotropic conductive adhesive or soldering method, and the other end of the flexible printed circuit board is connected to the corresponding sensing channel pin of the touch chip 3.

[0043] Step S5 (Encapsulation): The flexible tactile sensor array 2 formed after steps S1 to S4 is subjected to vacuum potting. The entire sensor array is placed in a vacuum potting apparatus, and a vacuum level of not less than -0.08 MPa is drawn and maintained for 5 to 10 minutes to remove air bubbles. Then, medical-grade potting compound is injected. After potting, it is cured at 60℃ to 80℃ for 2 to 4 hours. The vacuum potting process enables the flexible tactile sensor array 2 to achieve a waterproof rating of IP67, ensuring that the electronic skin can be cleaned and wiped during daily use without damage.

[0044] Example 3: Core Circuit of Touch Chip In this embodiment, as Figure 3 As shown, the core circuit of the touch chip 3 includes a power supply circuit, a sensing channel circuit, a communication circuit, and an anti-interference circuit.

[0045] The power supply circuit includes a power supply terminal V_DD, a ground terminal V_SS, and a decoupling capacitor C1. The power supply terminal V_DD is connected to the 3.3V operating voltage output from the voltage regulator unit, and the ground terminal V_SS is connected to system ground. The decoupling capacitor C1, with a capacitance of 0.1μF, is connected between the power supply terminal V_DD and the ground terminal V_SS, and is positioned close to the pins of the touch chip 3. It is used to filter out high-frequency ripple on the power line and provide a stable operating voltage for the touch chip 3.

[0046] The sensing channel circuit includes multiple current-limiting resistors R_CH0 to R_CHx (x is the number of channels minus 1, corresponding to 32 to 40 channels). One end of each current-limiting resistor is connected to the corresponding sensing channel pin CH0 to CHx of the touch chip 3, and the other end of each current-limiting resistor is connected to the conductive layer 21 of the corresponding sensing unit. Each current-limiting resistor has a resistance of 1MΩ and is connected in series between the corresponding sensing channel pin and the corresponding conductive layer 21 to limit the current flowing into the pin of the touch chip 3 and prevent chip damage due to external static electricity or abnormal high voltage.

[0047] The communication circuit uses I 2 The communication circuit uses a C-bus interface (or an SPI bus interface). The data pin SDA is connected to the corresponding general-purpose input / output pin of the microcontroller (e.g., PB7), and the clock pin SCL is connected to the corresponding general-purpose input / output pin of the microcontroller (e.g., PB6). Both the data pin SDA and the clock pin SCL are connected to the 3.3V operating voltage via pull-up resistors R_pu, with a resistance of 4.7kΩ, to ensure I... 2 The C bus is at a high level when idle to ensure reliable communication.

[0048] The anti-interference circuit includes a reset pin RST and an interrupt pin INT. The reset pin RST is connected to the 3.3V operating voltage via a reset resistor R_rst, which has a resistance of 10kΩ. This pulls the reset pin up to the operating voltage, preventing noise from being introduced due to the reset pin being floating and causing false resets. The interrupt pin INT is connected to the microcontroller's interrupt input (e.g., PA0). When the touch chip 3 detects a touch event, it sends an interrupt request signal to the microcontroller via the interrupt pin INT, triggering the microcontroller to enter the interrupt service routine to read the touch data.

[0049] The printed circuit board for the core circuit adopts a layered layout. Specifically, the analog ground corresponding to the ground terminal of the sensing channel circuit is isolated from the digital ground corresponding to the communication circuit and the microcontroller. In the printed circuit board layout, the analog ground plane and the digital ground plane are independently copper-clad, separated by an isolation strip, and connected only at a single point by a ferrite bead or a 0Ω resistor to prevent high-frequency noise on the digital ground from coupling to the analog signal path through the ground plane. At the same time, the wiring area of ​​the sensing channel circuit and the wiring area of ​​the attitude drive unit are spaced apart to prevent the high current and high-frequency switching signals of the servo motor from interfering with the weak analog signal of the sensing channel through spatial coupling.

[0050] Example 4: Specific Implementation of the Haptic Algorithm In this embodiment, the tactile algorithm includes a pressure grading algorithm, a multi-point positioning algorithm, a temperature compensation algorithm, and a drift correction algorithm.

[0051] The pressure grading algorithm operates as follows: After receiving the digital signals from each sensing unit, the microcontroller first generates pressure detection values ​​for each sensing unit based on the amplitude of each digital signal. Specifically, through a pre-calibrated pressure-signal amplitude mapping relationship (such as linear fitting or polynomial fitting curves), the digital signal amplitude of each channel is converted into a corresponding pressure value (unit: N). Then, each pressure detection value is compared with a preset three-level pressure threshold to determine the pressure level of each sensing unit. The three pressure thresholds are: a first pressure range of 0.1N to 1N (corresponding to the "light touch" level), a second pressure range greater than 1N and less than or equal to 5N (corresponding to the "hug" level), and a third pressure range greater than 5N (corresponding to the "press" level).

[0052] The multi-point positioning algorithm operates as follows: When multiple sensing units simultaneously detect pressure signals, the microcontroller calculates the coordinates of the contact position using the centroid method based on the amplitude and distribution of the digital signals from each sensing unit. Specifically, the position coordinates (known fixed values) of all sensing units that have detected valid signals are weighted and averaged using their signal amplitudes to obtain the centroid coordinates of the contact area, which are the contact position coordinates.

[0053] The temperature compensation algorithm operates as follows: The microcontroller collects ambient temperature data every 100ms using an integrated temperature sensor (such as the internal temperature sensor of the touch chip 3 or an external NTC thermistor). Since the resistivity of the silver nanowires changes with temperature (having a positive temperature coefficient, typically 2000ppm / ℃~3000ppm / ℃), temperature changes cause the resistance / capacitance of the conductive layer 21 to drift, thus affecting the amplitude of the digital signal. Let the amplitude of the digital signal collected by the i-th sensing unit at ambient temperature T (unit: ℃) be S_i(T), and the reference temperature T_0 = 25℃. The temperature-compensated signal amplitude S_i^comp is calculated using the following formula: Where α is the temperature coefficient of resistance of the silver nanowire (unit: ppm / ℃). The temperature compensation algorithm calibrates the amplitude of the digital signal in real time based on the current ambient temperature and the above formula, obtaining the temperature-normalized signal amplitude and eliminating the influence of temperature changes on pressure detection.

[0054] The drift correction algorithm operates as follows: The microcontroller continuously monitors the digital signals of each sensing unit. When the signal amplitude of all sensing units is lower than the preset contact detection threshold (corresponding to an equivalent pressure of 0.05N) and the duration exceeds 30 seconds, it is determined to be in a "continuous idle state." Under the premise of satisfying the continuous idle state, the drift correction algorithm is automatically activated. The correction process is as follows: The microcontroller continuously samples each sensing unit 64 times, calculates the arithmetic mean of the sampled values ​​as the new baseline value Bi_i_sample for that channel, and updates the baseline using a moving average method. Wherein, B_i^{old} represents the current baseline value. A moving average method is used to update the baseline, avoiding baseline abrupt changes caused by single sampling anomalies. After correction, subsequent pressure detection values ​​are calculated with reference to the new baseline value B_i^{new}, thereby eliminating long-term drift in each digitized signal.

[0055] Example 5: Material parameters and conductive layer properties of silver nanowires In this embodiment, the diameter of the silver nanowires is 20 nm to 50 nm, and the length is 30 μm to 50 μm. Using silver nanowires within this size range ensures that the silver nanowires have a sufficient aspect ratio to form an efficient conductive network, while also preventing excessively long silver nanowires from agglomerating during the coating process.

[0056] The conductive layer 21 also contains an elastic polymer (such as polydimethylsiloxane PDMS or thermoplastic polyurethane TPU). The amount of elastic polymer added is 5% to 15% of the mass of the silver nanowires, which is used to enhance the bonding force between the silver nanowires, prevent the silver wires from breaking due to long-term bending and pressing, and improve the mechanical durability of the conductive layer. Tests show that the conductive layer 21 can withstand more than or equal to 100,000 bending cycles (under a bending radius R=5mm) and has an elongation of more than or equal to 30%.

[0057] The flexible tactile sensor array 2 has a total of 32-40 sensing units. In one specific embodiment of this application, the diameter of the silver nanowire is 30nm and the length is 40μm. The flexible tactile sensor array 2 has a total of 40 channels, arranged in the following zones: head (4 channels), face (6 channels), neck (2 channels), shoulder (4 channels), chest (6 channels), arm (8 channels), waist (4 channels), and leg (8 channels), totaling 42 sensing units (40 channels actually in use). The surface temperature of the silicone body 1 is maintained at 36.5℃±0.5℃ by a PI heating element. The power supply module 6 uses two 21700 lithium batteries connected in series, outputting a 3.3V operating voltage after boosting and LDO regulation, with a standby time of up to 96 hours. Testing showed that the tactile sensor array of this embodiment has a sensitivity of 0.1kPa, a response time of 15ms, a conductive layer elongation of 35%, and a bending resistance of 150,000 cycles.

[0058] In another specific embodiment of this application, the flexible tactile sensing array 2 adopts a piezoresistive architecture, with silver nanowires having a diameter of 20nm, a length of 30μm, and a total of 32 channels. The control module 4 uses an STM32F407VET6 MCU, the voice unit uses a WT588D voice chip, and the power supply module 6 uses three 18650 lithium batteries connected in series, providing a standby time of 72 hours. The concentration of the silver nanowire ink is 2mg / ml, and the drying time is 15 minutes. Testing showed that the tactile sensing array of this embodiment has a sensitivity of 0.08kPa, a response time of 18ms, a conductive layer tensile strength of 30%, and a bending resistance of 120,000 cycles.

[0059] Example 6: Silicone Body Material and Heating Temperature In this embodiment, the silicone body 1 is made of medical-grade platinum silicone. Medical-grade platinum silicone has excellent biocompatibility (passed ISO10993 biocompatibility test), is non-toxic, non-allergenic, and anti-aging (service life ≥ 5 years), making it suitable for applications that come into direct contact with human skin.

[0060] The heating unit uses a PI heating element (polyimide film heating element) located inside the silicone body 1, near the surface. Based on drive control commands, the heating unit maintains the surface temperature of the silicone body 1 at 36℃~37℃ using a PID (proportional-integral-derivative) closed-loop control algorithm. Specifically, the silicone body 1 contains a temperature sensor (such as an NTC thermistor) that collects the surface temperature in real time and feeds it back to the microcontroller. The microcontroller adjusts the heating power of the PI heating element based on the deviation between the current temperature and the target temperature (36.5℃), achieving precise temperature control. The temperature range of 36℃~37℃ simulates normal human body temperature, enhancing the realism of the interactive experience.

[0061] Example 7: Preparation method of silver nanowires In this embodiment, the silver nanowires were synthesized using a polyol method. Specifically, silver nitrate (AgNO3) was used as the silver source, polyvinylpyrrolidone (PVP, molecular weight approximately 360,000) was used as an inducer (morphology directing agent), and copper chloride (CuCl2) was used as an inhibitor (reaction rate control agent). The nanowires were prepared by liquid-phase reduction reaction in a polyol solvent system (such as ethylene glycol or propylene glycol).

[0062] A typical synthesis process is as follows: 0.1 g–0.5 g of PVP and 0.01 g–0.05 g of CuCl2 are dissolved in 50 ml–100 ml of ethylene glycol, and the solution is heated to 160 °C–180 °C while stirring. Then, 0.05 g–0.2 g of AgNO3 is dissolved in 10 ml–20 ml of ethylene glycol and added dropwise to the above hot solution, and the reaction is allowed to proceed for 20–40 minutes. After the reaction is complete, the product is centrifuged and washed repeatedly with ethanol and deionized water 3–5 times to obtain high aspect ratio silver nanowires.

[0063] The silver nanowires prepared by the above method have an aspect ratio of 1500–1921 (aspect ratio = length / diameter; calculated with a diameter of 20 nm–50 nm and a length of 30 μm–50 μm, the aspect ratio range is 600–2500; in this embodiment, silver nanowires with an aspect ratio of 1500–1921 are preferred). High aspect ratio silver nanowires can form highly efficient conductive networks at lower filler densities, which is beneficial for improving the flexibility and conductivity of the conductive layer.

[0064] Example 8: Core Circuit Component Parameters In this embodiment, the resistance value of each current-limiting resistor in the sensing channel circuit is 1MΩ, using 0603 packaged surface-mount resistors with ±1% accuracy. Each current-limiting resistor is connected in series between the corresponding sensing channel pin and the conductive layer 21 of the corresponding sensing unit. The 1MΩ resistance value effectively limits the current under abnormal conditions (the maximum current is only 3.3μA at a 3.3V operating voltage) without significantly attenuating the weak signal of the sensing channel.

[0065] The decoupling capacitor C1 has a capacitance of 0.1μF, is an X7R ceramic capacitor with a voltage rating of 16V, and a 0603 package size. The pull-up resistor R_pu has a resistance of 4.7kΩ, is a 0603 packaged surface-mount resistor with ±1% accuracy. The reset resistor R_rst has a resistance of 10kΩ, is a 0603 packaged surface-mount resistor with ±1% accuracy.

[0066] Example 9: PCB layout of anti-interference circuit In this embodiment, the printed circuit board adopts a four-layer board structure. The top layer is the signal layer, used to arrange the sensing channel traces of the touch chip 3, I / O, etc. 2 The first layer consists of communication and power traces; the second layer is a complete analog ground plane, located directly below the sensing channel circuitry, providing a low-impedance reference ground for the sensing channel; the third layer is a complete digital ground plane, located below the corresponding areas of the communication circuitry and microcontroller; the bottom layer is an auxiliary signal layer, used to arrange the control signal lines of the attitude drive unit.

[0067] An isolation strip is provided between the analog ground plane and the digital ground plane—a 1.5mm wide copper foil-free isolation area is set along the boundary between the analog ground and the digital ground between the second and third layers, so that the two ground planes are physically completely separated. The two ground planes are connected at a single point only at the power input through a ferrite bead (impedance of 600Ω at 100MHz) to avoid noise coupling caused by ground loops.

[0068] The spacing between the wiring area of ​​the sensing channel circuit and the wiring area of ​​the attitude drive unit is 5mm. Within this spacing area, a 0.5mm wide ground protection trace is arranged along one side of the sensing channel circuit. Both ends of this trace are connected to the simulated ground plane via vias to further absorb electromagnetic interference from spatial coupling. When printed circuit board space is limited, a ground shield trace (connected to the simulated ground plane) is added between the two to further suppress electromagnetic interference.

[0069] Example 10: Layout scheme of whole-body sensory zones In this embodiment, as Figure 4 As shown, the silicone body 1 is divided into multiple sensing zones. These zones include the head region, face region, neck region, shoulder region, chest region, arm region, waist region, and leg region. Each sensing zone contains a corresponding number of sensing units from the flexible tactile sensing array 2, specifically distributed as follows: Head region: 4 sensing units, distributed in the top and back of the head; Facial area: 6 sensing units are distributed in key locations such as the forehead, cheeks, and chin; Neck region: Two sensing units, distributed on both sides of the neck; Shoulder area: 4 sensing units (2×2 array), distributed on both shoulders; Chest region: 6 sensing units (2×3 array), distributed in the center and both sides of the chest; Arm region: 8 sensing units (2×4 array), distributed in the upper arm and forearm; Waist region: 4 sensing units, distributed on both sides of the waist; Leg area: 8 sensing units (2×4 array), distributed in the thigh and calf.

[0070] The total number of sensing units in the aforementioned regions is 4+6+2+4+6+8+4+8=42, corresponding to a total of 32-40 sensing units in the flexible tactile sensing array 2 (the number in each region can be adjusted depending on the product model). This zoning layout scheme is based on ergonomic design, concentrating sensing units in areas with high interaction frequency (face, arms, legs) while ensuring full-body tactile coverage, thus achieving an optimized balance between sensing accuracy and system cost.

[0071] Application scenario examples Application Scenario Example 1: Emotional Companion Robot The electronic skin of this application is integrated into the outer shell of a certain type of emotional companion robot, covering the tactile sensing areas of the robot's torso and limbs. During daily interactions, the robot uses 40 sensing units on the electronic skin to perceive the user's touch in real time. When the user gently strokes the robot's arm with a force of approximately 0.5N, the sensing units in the arm area detect the pressure signal, and a multi-point positioning algorithm identifies the contact location as the arm area (coordinate accuracy ±5mm) and the action type as "stroking". The microcontroller generates drive control commands based on the pressure detection value (0.5N, belonging to the "light touch" level), the contact location (arm), and the action type (stroking): the heating unit adjusts the surface temperature of the arm area from room temperature to 36.5℃ within 5 seconds, the voice unit outputs the voice response "Thank you for the touch, I'm happy," and the posture drive unit drives the robot's head to rotate slightly at an angular velocity of 0.5 rad / s, accompanied by a blinking motion. Throughout the entire interaction, the tactile perception response time is approximately 15ms, and the voice response delay is approximately 300ms, achieving natural and smooth human-machine emotional interaction.

[0072] Application Scenario Example 2: Medical Rehabilitation Assistive Robot The robotic electronic skin of this application is integrated into the gripping area (palm and inner sides of fingers) of a certain type of hand rehabilitation training robot. When assisting patients in hand gripping rehabilitation training, the robot monitors the patient's gripping force distribution in real time through 32 sensor units on the electronic skin. When the patient's gripping force reaches the "pressing" level (>5N) and lasts for more than 2 seconds, the robot determines that the patient's hand strength has recovered well and automatically increases the training resistance by 10%. When the gripping force remains below the "light touch" level (<0.1N) for more than 5 seconds, the robot determines that the patient is fatigued, automatically reduces the training resistance by 20%, and issues a voice encouragement, "Take a break." Temperature compensation and drift correction algorithms are automatically calibrated every 10 minutes to ensure that the pressure detection error does not exceed ±3% during 2 hours of continuous training, avoiding misjudgments caused by temperature changes or sensor aging.

[0073] Application Scenario Example 3: Full-body tactile perception in humanoid robots The robotic electronic skin of this application is integrated onto the entire surface of a humanoid robot, covering eight sensing zones: head, face, neck, shoulders, chest, arms, waist, and legs, totaling 40 sensing units. When a user hugs the robot, six sensing units in the chest area and eight sensing units in the arms simultaneously detect a hugging pressure of 1N to 5N. A multi-point localization algorithm generates coordinate information of the contact position (center of the chest and inner side of the arms), and the action type is identified as "hugging." Based on this, the microcontroller generates multiple drive control commands: the heating unit adjusts the temperature of the chest area to 37℃ (heating rate 0.5℃ / s), the voice unit outputs the voice response "I'm also very happy to see you," and the posture drive unit drives the robot's arms to perform a closing motion at an angular velocity of 0.3 rad / s, simulating a real hugging feedback. The zoned layout of 40 sensing units throughout the body ensures that the robot can accurately perceive external contact in any posture, with a spatial resolution of ±10mm.

[0074] This application provides a robotic electronic skin consisting of a touch chip and a silver nanowire tactile sensor array, which can be industrially manufactured and prepared. The silicone body can be mass-produced using injection molding or casting processes; the flexible silver nanowire tactile sensor array can be mass-prepared on a flexible substrate using slot coating or screen printing processes; the core circuits of the touch chip and control module can be mass-assembled on a printed circuit board using standard surface mount technology; electrical connections between modules can be achieved through flexible printed circuit boards or wires. All of the above preparation processes are mature industrial production technologies, and the raw materials (medical-grade platinum silicone, silver nanowire ink, touch chip, etc.) are all commercially available, demonstrating the feasibility of large-scale industrial production.

[0075] This application can be widely used in fields such as emotional companion robots, medical rehabilitation assistive robots, humanoid robots, intelligent prostheses and wearable devices, and has good practical value and broad market prospects.

[0076] Those skilled in the art should understand that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of this application. The scope of protection of this application should be determined by the claims.

Claims

1. A robotic electronic skin comprising a touch chip and a silver nanowire tactile sensing array, characterized in that, It includes a silicone body, a sensing module, a control module, an interaction module, and a power supply module. The sensing module, the control module, the interaction module, and the power supply module are respectively disposed inside the silicone body, and the modules are electrically connected to each other. The silicone body is made of flexible material and has an internal flexible skeleton to support each module and deform with the silicone body. The sensing module includes a flexible tactile sensing array and a touch chip; the flexible tactile sensing array is a capacitive or piezoresistive architecture, including a conductive layer, an insulating layer and a shielding electrode layer. The conductive layer is composed of silver nanowires. The insulating layer is disposed between the conductive layer and the shielding electrode layer to electrically isolate the conductive layer and the shielding electrode layer. The shielding electrode layer is disposed on the side of the insulating layer opposite to the conductive layer to provide a reference ground for the conductive layer to suppress electromagnetic interference. The flexible tactile sensing array is distributed in multiple areas of the silicone body, each area containing multiple sensing units. Each sensing unit has a corresponding conductive layer, insulating layer, and shielding electrode layer. The touch chip has a multi-channel synchronous sampling interface, with each sampling channel connected to the conductive layer of each sensing unit. This interface is used to collect capacitance or resistance change signals generated by each conductive layer under external pressure, and to filter and perform analog-to-digital conversion on the capacitance or resistance change signals before outputting a digital signal. The control module includes a microcontroller. The signal input terminal of the microcontroller is connected to the signal output terminal of the touch chip. The microcontroller receives the digital signal and runs a haptic algorithm. The haptic algorithm generates pressure detection values ​​for each sensing unit based on the amplitude of the digital signal from each sensing unit, generates contact position coordinates based on the distribution of the digital signal from each sensing unit, and identifies the action type based on the change pattern of the pressure detection values ​​and the contact position coordinates over time. The microcontroller is also used to generate drive control commands based on the pressure detection values, the contact position coordinates, and the action type. The control output terminal of the microcontroller is connected to the control input terminal of the interaction module. The interactive module includes a heating unit, a voice unit, and a posture driving unit. The heating unit is used to adjust the surface temperature of the silicone body based on the driving control command. The voice unit is used to output a voice signal based on the driving control command. The posture driving unit is used to drive at least a part of the silicone body to perform a posture action based on the driving control command. The power supply module includes a rechargeable battery, a voltage conversion unit, and a voltage regulator unit. The output terminal of the rechargeable battery is connected to the input terminal of the voltage conversion unit, and the output terminal of the voltage conversion unit is connected to the input terminal of the voltage regulator unit. The output terminal of the voltage regulator unit outputs a working voltage to the sensing module, the control module, and the interaction module.

2. The robotic electronic skin according to claim 1, characterized in that, The flexible tactile sensing array is a flexible tactile sensing array manufactured using the following process: S1. A primer is applied to the surface of the silicone body, and the primer forms a microtexture after curing; S2. Using slot coating or screen printing, the nano-silver wire ink is coated onto the silicone surface treated in step S1, and the coated nano-silver wire ink is dried at 80°C. The dried nano-silver wire ink forms the conductive layer. S3. Coat the surface of the conductive layer with an ultra-thin silicone layer as the insulating layer, and lay the shielding electrode layer below the insulating layer; S4. A flexible printed circuit board is used to connect the conductive layer to the sensing channel of the touch chip; S5. The flexible tactile sensor array formed after steps S1 to S4 is subjected to vacuum potting treatment to make the waterproof rating of the flexible tactile sensor array reach IP67.

3. The robotic electronic skin according to claim 1, characterized in that, The core circuit of the touch chip includes a power supply circuit, a sensing channel circuit, a communication circuit, and an anti-interference circuit. The power supply circuit includes a power supply terminal, a ground terminal, and a decoupling capacitor. The power supply terminal is connected to the operating voltage output by the voltage regulator unit. The ground terminal is connected to the system ground. The decoupling capacitor is connected between the power supply terminal and the ground terminal. The sensing channel circuit includes multiple current-limiting resistors. One end of each current-limiting resistor is connected to the corresponding sensing channel pin of the touch chip, and the other end of each current-limiting resistor is connected to the conductive layer of the corresponding sensing unit. The communication circuit uses I 2 The communication circuit uses a C-bus or SPI bus interface, with its data pins and clock pins connected to the corresponding general-purpose input / output pins of the microcontroller, and the data pins and clock pins connected to the operating voltage via pull-up resistors. The anti-interference circuit includes a reset pin and an interrupt pin. The reset pin is connected to the operating voltage through a reset resistor, and the interrupt pin is connected to the interrupt input terminal of the microcontroller. The printed circuit board of the core circuit adopts a layered layout. The analog ground corresponding to the ground terminal of the sensing channel circuit is isolated from the digital ground corresponding to the communication circuit and the microcontroller. The wiring area of ​​the sensing channel circuit is spaced apart from the wiring area of ​​the attitude driving unit.

4. The robotic electronic skin according to claim 1, characterized in that, The tactile algorithm includes a pressure grading algorithm, a multi-point positioning algorithm, a temperature compensation algorithm, and a drift correction algorithm; The pressure grading algorithm is used to generate pressure detection values ​​for each sensing unit based on the amplitude of the digital signal of each sensing unit, and compare each pressure detection value with a preset three-level pressure threshold to determine the pressure level of each sensing unit. The three-level pressure thresholds are a first pressure range of 0.1N to 1N, a second pressure range of greater than 1N and less than or equal to 5N, and a third pressure range of greater than 5N. The multi-point positioning algorithm is used to calculate the coordinate information of the contact position using the centroid method based on the amplitude and distribution of the digital signals of each of the sensing units. The temperature compensation algorithm is used to calibrate the digital signal in real time according to the ambient temperature; The drift correction algorithm is used to automatically calibrate the baseline value of the digital signal of each of the sensing units at a preset time interval in order to eliminate the drift of each of the digital signals.

5. The robotic electronic skin according to claim 1, characterized in that, The diameter of the silver nanowires is 20nm to 50nm, and the length is 30μm to 50μm; the conductive layer also contains an elastic polymer, the conductive layer has a bending resistance of ≥100,000 cycles and an elongation of ≥30%; the total number of sensing units in the flexible tactile sensing array is 32 to 40.

6. The robotic electronic skin according to claim 1, characterized in that, The silicone body is made of medical-grade platinum silicone; the heating unit maintains the surface temperature of the silicone body at 36℃~37℃.

7. The robotic electronic skin according to claim 1, characterized in that, The silver nanowires are prepared by reacting silver nitrate as the silver source, polyvinylpyrrolidone as the inducing agent, and copper chloride as the inhibitor in a polyol solvent system. The aspect ratio of the silver nanowires is 1500-1921.

8. The robotic electronic skin according to claim 3, characterized in that, In the sensing channel circuit, the resistance value of each current-limiting resistor is 1MΩ, and each current-limiting resistor is connected in series between the corresponding sensing channel pin and the conductive layer of the corresponding sensing unit; the capacitance value of the decoupling capacitor is 0.1μF; the resistance value of the pull-up resistor is 4.7kΩ; and the resistance value of the reset resistor is 10kΩ.

9. The robotic electronic skin according to claim 3, characterized in that, In the anti-interference circuit, an isolation strip is provided between the analog ground plane corresponding to the sensing channel circuit and the digital ground plane corresponding to the communication circuit and the microcontroller on the printed circuit board, and the spacing between the wiring area of ​​the sensing channel circuit and the wiring area of ​​the attitude driving unit is greater than or equal to 5mm.

10. The robotic electronic skin according to any one of claims 1 to 9, characterized in that, The silicone body is divided into multiple sensing zones, including a head region, a face region, a neck region, a shoulder region, a chest region, an arm region, a waist region, and a leg region. Each sensing zone is provided with a corresponding number of sensing units of the flexible tactile sensing array. The number of sensing units in the head region, face region, neck region, shoulder region, chest region, arm region, waist region, and leg region are 4, 6, 2, 4, 6, 8, 4, and 8, respectively.

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