Thermal-pressure pain sense sensing device simulating human nerve synaptic function

Abstract

The invention discloses a heat-pressure pain sense sensing device simulating a human nerve synaptic function. The sensing device is mainly composed of a triboelectric sensor, a resistance-type temperature sensor and an electrochemical transistor. The triboelectric sensor is used as a pressure sensor and can output different voltages when being pressed, the triboelectric sensor is connected with the grid electrode of the electrochemical transistor, and the grid electrode voltage of the electrochemical transistor is regulated and controlled through the triboelectric sensor to realize regulation and control on the source drain current IDS of the transistor; the resistive temperature sensor is connected in series with the source and drain electrodes of the electrochemical transistor, and regulation and control of source and drain loop current IDS are realized through resistance change. According to the invention, simulation perception of heat pain and pressing pain is realized, stimulation modes can be distinguished according to different IDS linear shapes, and two pain sense signals can be integrated and distinguished when pressure stimulation and temperature stimulation are carried out at the same time. And the humanoid skin or humanoid robot is endowed with various injury perception capabilities and more efficient injury prevention capability.

Description

Technical Field

[0001] The present invention belongs to the field of neuromorphic perception engineering, and specifically relates to a heat-pressure pain perception device that simulates the function of human neural synapses. Background Art

[0002] Our human skin senses the stimulation of the external environment through a large number of tactile receptors, including mechanical receptors, temperature receptors, etc. The receptors sense external stimuli and transmit the stimulation signals to the brain through neural synapses to help us interact with the external environment. This tactile perception process will form tactile memory and store it in our brain. The current work mainly focuses on using sensors as receptors to imitate human skin to sense some external stimuli and to store and process information through a computing system based on the von Neumann architecture. However, human skin is different from electronic skin. The neural network unit of the human body is very large and can process information in parallel, which greatly reduces energy consumption so that we can better handle our own perception and movement behavior.

[0003] At present, research on pain sensors has also achieved certain results. Single-mode pain neuromorphic sensing devices based on artificial synapses can simulate the most important memory function of pain, but due to the limitations of the output of a single pain signal, they cannot simulate the process of perceiving multiple harmful stimuli and cannot provide a more comprehensive early warning of damage. In addition, in the process of using only sensors for pain perception, due to the lack of neuromorphic devices such as electrochemical transistors, it is impossible to simulate the memory of pain and realize parallel processing, that is, integration and differentiation of different pain information. However, the current multi-mode neuromorphic sensing devices have not realized the integration and differentiation of multiple input information. They are faced with problems such as confusion and indistinguishability of multiple signal coupling when inputting simultaneously, multi-channel input and multi-channel output, and failure to process in parallel, which increases power consumption. Summary of the invention

[0004] In response to the problems in the above-mentioned background technology, the present invention provides a heat-pressure pain perception device that simulates the function of human nerve synapses, which can simulate the memory of different types of pain signals, integrate and distinguish signals when multiple stimuli are input at the same time, and simulate the pain signal response of radiant heat stimulation and contact heat stimulation, giving the robot more accurate and keen perception ability and more efficient injury prevention ability.

[0005] The present invention can simulate the signal output of human skin under different pressure stimulations by matching the triboelectric sensor with the electrochemical transistor, that is, the source-drain loop current I DSIt simulates the excitatory postsynaptic current EPSC of human neurons and can store pain signals for a period of time, that is, memory simulation, thereby realizing tenderness perception. By matching the resistive temperature sensor with the electrochemical transistor, the signal output of the human skin under different temperature stimuli can be simulated, thereby realizing thermal pain perception. By giving full play to the respective characteristics of the triboelectric sensor, the resistive temperature sensor, and the electrochemical transistor, the memory simulation of different types of pain signals is realized at the same time, as well as the signal integration and differentiation when two stimuli are input at the same time.

[0006] The technical solution adopted by the present invention is as follows:

[0007] 1. A heat-pressure pain sensing device that mimics the function of human nerve synapses

[0008] include:

[0009] Electrochemical transistor: The electrochemical transistor is an N-type electrolyte electrochemical transistor, that is, the main carrier of the channel is electrons; the source-drain current I output by the electrochemical transistor DS Simulates the excitatory postsynaptic current EPSC of human neurons.

[0010] Triboelectric sensor: It is equivalent to an ideal power supply. It can output different voltages when under pressure. It is connected in series with the gate of the electrochemical transistor. Different voltages are applied to the gate according to the size of the external pressure stimulus to achieve the source-drain current I of the electrochemical transistor. DS Regulation;

[0011] Resistive temperature sensor: When heated, the resistance decreases. The resistive temperature sensor is connected in series with the source and drain of the electrochemical transistor, and the source and drain current I of the transistor is changed by applying temperature stimulation. DS regulation.

[0012] One end of the triboelectric sensor is grounded, and the other end is connected to the gate of the electrochemical transistor to form a gate loop; the two ends of the resistance temperature sensor are led out through wires, one end is connected to the positive electrode of the power supply, and the other end is connected to the drain of the electrochemical transistor, and the negative electrode of the power supply is connected to the source of the electrochemical transistor to form a source-drain loop. A 500kΩ fixed resistor is connected in parallel to the resistance temperature sensor.

[0013] The electrolyte material used in the gate dielectric of the electrochemical transistor is a chitosan film, and the channel layer uses an indium tin oxide (ITO) semiconductor film.

[0014] The triboelectric sensor includes a PET substrate layer, a top Cu conductive layer, an EVA support layer, a PDMS / CaCuO6Ti2 dielectric layer, a bottom Cu conductive layer, and a PET substrate layer connected in sequence. The triboelectric sensor has the characteristic of self-power supply. When subjected to an external load, the distance between the top Cu conductive layer and the dielectric layer decreases. Due to charge induction, charge transfer occurs between the upper and lower conductive layers, which then generates a potential difference, which is converted into a gate voltage stimulus.

[0015] Because the mechanism of triboelectric sensor is charge transfer, and when in high temperature environment, the thermal expansion or dielectric loss of the dielectric layer will affect the voltage output of the triboelectric sensor, and thus cannot accurately sense the tenderness signal, so when the dielectric layer material of the triboelectric sensor of the present invention is subjected to temperature stimulation and pressure stimulation at the same time, the dielectric layer material used is calcium copper titanate -CaCuO6Ti2, which has an abnormal giant dielectric constant (ε≈104-105) and extremely low loss (tgδ≈0.03), especially in a wide temperature range (100-400K) The dielectric constant value is almost unchanged, reflecting the high thermal stability of the dielectric response. Thus reducing the influence of temperature on the triboelectric sensor.

[0016] The preparation method of the triboelectric sensor is as follows:

[0017] (1) Preparation of PDMS solution: PDMS prepolymer and curing agent were added into a test tube in a mass ratio of 10:1, stirred with a glass rod for 10 min to mix evenly, and then placed in a centrifuge for high-speed centrifugation at 6000 rpm until the bubbles in the PDMS solution completely disappeared, thereby obtaining a standby PDMS solution.

[0018] (2) PDMS / CaCuO6Ti2 mixed solution: Place the CaCuO6Ti2 powder in a 70-degree oven for drying, then add the PDMS solution and CaCuO6Ti2 powder into a test tube in a mass ratio of 20:3, and stir with a glass rod for 10 minutes to mix evenly. A PDMS / CaCuO6Ti2 mixed solution is obtained.

[0019] (3) Commercial sandpaper molding: Cut a certain area of ​​sandpaper and stick it to a 10×10 cm square glass plate. Slowly pour the prepared PDMS / CaCuO6Ti2 mixed solution on the surface of the commercial sandpaper, and keep pouring slowly. Place the glass plate on a spin coater for spin coating and thinning, then put it into a freeze dryer for vacuum treatment until the bubbles disappear completely, then put the glass plate into a 60-degree oven and let it stand for 30 minutes before taking it out. Separate the prepared PDMS / CaCuO6Ti2 film from the sandpaper, thereby obtaining a film with a sandpaper microstructure on one side;

[0020] The inverted film sandpaper is 3000 mesh sandpaper;

[0021] (4) Electrode preparation: A 50 μm copper foil was pasted on the upper and lower layers of flexible polyethylene terephthalate (PET) film to prepare a Cu electrode, which was then led out through an enameled wire for testing;

[0022] (5) Sensor assembly: The side of the PDMS / CaCuO6Ti2 film without microstructure is attached to the bottom copper electrode, and a 2 mm thick EVA sponge is attached around the PDMS / CaCuO6Ti2 film as a support. The top Cu electrode layer is attached to the edge EVA sponge, so that there is a gap of about 1.5 mm between the top Cu electrode layer and the PDMS / CaCuO6Ti2 film. The outside is insulated and packaged with PI film to complete the preparation of the triboelectric sensor;

[0023] The resistive temperature sensor comprises a PET substrate layer, a LIG electrode layer, a NiO temperature-sensitive layer, and a PI packaging layer.

[0024] The preparation method of the resistive temperature sensor is as follows:

[0025] (1) Preparation of NiO ink: polyvinyl pyrrolidone (PVP) powder and 1-pentanol solution were mixed at a mass ratio of 1:10, and then the obtained mixed solution was mixed with NiO nanoparticles (<50 nm) at a mass ratio of 2:1. The final mixed solution was ultrasonicated and stirred until the nanoparticles were completely dispersed to finally form NiO ink;

[0026] (2) Preparation of LIG interdigital electrodes: The commercial PI film was cleaned with deionized water, ethanol and acetone respectively, and a 25 μm thick PI film was pasted on a 0.1 mm thick PET film. The dried PI film was laser scanned using a programmable laser engraving machine to prepare interdigital LIG electrodes. Then, copper wires were connected to the LIG electrodes through conductive silver paste and led out.

[0027] (3) Preparation of NiO temperature-sensitive layer: The NiO temperature-sensitive layer was prepared by drop coating. The prepared NiO ink was drop coated on the LIG electrode using a syringe to ensure that the electrode edge was completely covered. The obtained sample was naturally dried in the environment to complete the preparation of the temperature sensor;

[0028] 2. Heat-pressure pain perception method using the above device

[0029] The perception process includes the following:

[0030] 1) Simulate the force stimulation of human skin:

[0031] Apply different loads to the triboelectric sensor. After the triboelectric sensor is subjected to force, the distance between the upper and lower electrodes decreases. Based on the principle of charge induction, the charge is transferred between the upper and lower electrodes to generate a potential difference, which causes the voltage applied to the gate of the electrochemical transistor to increase or decrease. The source-drain current I DS Generate mutations, that is, simulate the excitatory postsynaptic current EPSC, and simulate the neural electrical signal response when the skin is stimulated by force; because the triboelectric sensor is a dynamic pressure sensor, the line type is a quasi-sine wave signal, that is, a positive and negative AC signal, so the source-drain current signal is also similar to the AC signal, and the typical positive gate voltage I DS The signals are differentiated.

[0032] 2) Simulate thermal stimulation of human skin (radiant heat):

[0033] When the resistive temperature sensor is subjected to external thermal stimulation, the resistance of the NiO temperature-sensitive layer decreases rapidly, causing the resistance of the entire source-drain loop to decrease, and the source-drain loop current I DS Increase, simulating the increase of excitatory postsynaptic current EPSC, that is, the neural electrical signal response when the skin is stimulated by heat, and the linear shape is similar to the typical positive gate voltage I DS , which is different from the above-mentioned tenderness signals.

[0034] 3) Simulating the simultaneous thermal and force stimulation of human skin (contact heat / heat-pressure):

[0035] The triboelectric sensor and the resistive temperature sensor are stacked vertically together. The output voltage of the triboelectric sensor and the resistance of the NiO temperature-sensitive layer are regulated by external force-heat stimulation, and then the gate voltage and the source-drain circuit resistance are regulated, so as to output the excitatory postsynaptic current EPSC when the skin is subjected to heat stimulation and force stimulation at the same time, simulating the neural electrical signal response when the skin is subjected to heat stimulation and force stimulation at the same time. The linear shape is two segments with different slopes I DS The superimposed signal is distinguishable from the above-mentioned tenderness signal and heat pain signal, and can also simulate the different EPSC outputs when the human skin is stimulated by radiant heat and contact heat, which can more accurately identify the external stimulation mode;

[0036] The source-drain current I through the electrochemical transistor DS The excitatory postsynaptic current EPSC of human neurons is simulated to characterize the magnitude of the stimulation to the skin. DS The line shape of EPSC is used to distinguish different stimulation modes, and the segmented line shape of EPSC is used to distinguish pressure pain signals and heat pain signals during simultaneous stimulation.

[0037] Simulating the degree of skin pressure through triboelectric sensors and electrochemical transistors;

[0038] Simulate skin heating using resistive temperature sensors and electrochemical transistors;

[0039] Beneficial effects of the present invention:

[0040] The present invention gives full play to the memory characteristics of electrochemical transistors and combines the respective advantages of triboelectric sensors and resistive temperature sensors. It can not only realize the memory simulation of different pain signals, but also distinguish the types and methods of external stimuli, as well as integrate and distinguish signals when multiple stimuli are input at the same time, simulating the process of human skin being stimulated by external damage, and giving the robot more accurate and keen damage perception ability and more efficient damage prevention ability. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is a schematic diagram of the overall connection of the heat-pressure pain perception device that mimics the function of human nerve synapses of the present invention;

[0042] Figure 2 It is a triboelectric sensor and a resistive temperature sensor of a heat-pressure pain perception device that imitates the function of human nerve synapses;

[0043] In the figure: 1-PET substrate layer, 2-top Cu conductive layer, 3-PDMS / CaCuO6Ti2 dielectric layer, 4-EVA support layer, 5-bottom Cu conductive layer, 6-PET substrate layer;

[0044] Figure 3 It is a resistive temperature sensor of a heat-pressure pain perception device that imitates the function of human nerve synapses;

[0045] In the figure: 7-PI encapsulation layer, 8-NiO temperature-sensitive layer, 9-LIG electrode layer, 10-PET substrate layer;

[0046] Figure 4 is the electrochemical transistor source-drain current I DS Time accumulation data graph, duration is 40-80-120-160-200-240ms, fixed gate voltage is 1V;

[0047] Figure 5 is the source-drain current I of the electrochemical transistor when the triboelectric sensor is stimulated for 10 s DS Test data graph, fixed pressure is 10kPa;

[0048] Figure 6 It is a line graph of tenderness signal, similar to AC signal;

[0049] Figure 7 is a line graph of the thermal pain signal, similar to the typical positive gate voltage I DS Signal;

[0050] Figure 8 It is the test data diagram of integrated superimposed signal (heat-pressure pain);

[0051] In the figure: 11 - heat pain signal of a single stimulus, 12 - pressure pain signal in the integrated signal, 13 - heat pain signal superimposed on the pressure pain signal in the integrated signal. DETAILED DESCRIPTION

[0052] The present invention will be further described below in conjunction with the accompanying drawings and specific implementations.

[0053] The present invention is a heat-pressure pain perception device that simulates the function of human nerve synapses. Figure 1 As shown, the triboelectric sensor is connected in series with the gate of the electrochemical transistor to regulate the gate voltage and then realize the source-drain loop current I DS The resistance temperature sensor is connected in series with the source and drain of the electrochemical transistor, and the overall resistance of the source-drain circuit is changed by the resistance change of the temperature sensor to achieve the control of the source-drain current I DS regulation.

[0054] The electrochemical transistor of the present invention is an N-type electrolyte electrochemical transistor, and the gate dielectric is a chitosan electrolyte film containing a large number of mobile charged ions. The triboelectric sensor has the characteristic of self-power supply, and can output different voltages according to the size of the external pressure stimulus, that is, different voltages are applied to the gate of the electrochemical transistor. The voltage change of the transistor gate causes the mobile ions in the chitosan electrolyte layer to gather in different directions according to their polarity, and finally forms two layers of positive and negative charge layers with a thickness of nanometer level at the interface between the electrolyte layer and the channel layer and at the interface between the electrolyte layer and the gate electrode. The channel layer between the source and drain electrodes obtains a large number of carriers, which is equivalent to a smaller resistance, thereby making the source and drain loop current I DS The double electric layer composed of positive and negative charge layers at two interfaces makes the chitosan electrolyte have a large specific capacitance, so the electrochemical transistor can work at an ultra-low gate voltage, greatly reducing the power consumption required by the device. The conduction of the source and drain of the electrochemical transistor is similar to the principle of the triode. The conduction of the source and drain channel is achieved by regulating the migration of ions in the chitosan electrolyte layer to the channel through the gate electrode voltage. This process is very similar to the process of different neurotransmitters in biological synapses from the presynaptic membrane through the synaptic cleft to the postsynaptic membrane. Therefore, electrochemical transistors have become a hot field for imitating the perception function of biological neural synapses.

[0055] The present invention is based on the principle of self-powered triboelectric sensor. Figure 2 The triboelectric sensor shown is connected in series with the gate of the electrochemical transistor, and Figure 3The resistive temperature sensor shown is connected in series with the source and drain of the electrochemical transistor, which can simultaneously realize the memory simulation of multiple pain signals. DS The line shape is used to distinguish between pressure pain stimulation and heat pain stimulation, and the pressure pain signal and heat pain signal are distinguished from the superimposed curve when the two stimuli are applied simultaneously through the difference in response speed of the two stimuli.

[0056] Reasons and differentiation strategies for selecting sensors:

[0057] The pain neurons in the human body can process different types of pain stimulus signals in parallel. Most of the current neuromorphic devices are single stimulus simulations. Everyone focuses on connecting pressure sensors or temperature sensors in series with the gate of the transistor to simulate tenderness or heat pain. However, the electrochemical transistor is a three-terminal device. It is a possible approach to connect one sensor in series in the source-drain loop and another sensor in series with the gate. In this way, the source-drain loop current I of the electrochemical transistor can be controlled by two sensors. DS However, when two sensors are stimulated at the same time, the signals of the two stimuli will be coupled with each other, which is not conducive to distinguishing the degree of tenderness and heat pain.

[0058] And the electrochemical transistor has time accumulation. When we apply a fixed voltage stimulus to the gate for a period of time, the source-drain current signal of the transistor will produce an accumulation signal, that is, it will first rise to a certain level and then rise slowly, such as Figure 4 As shown in the figure, a fixed voltage stimulus of different durations is applied to the transistor gate, ranging from 40ms to 240ms. DS It shows a continuous upward trend, indicating that the longer the voltage stimulation time, the higher the I DS The larger. Currently, everyone is focusing on connecting the pressure sensor or temperature sensor in series with the gate of the transistor, and based on the voltage division principle, changing the resistance of the sensor by load or temperature to change the voltage distributed on the gate. Then when a fixed pressure stimulus or heat stimulus is applied for a period of time, it is equivalent to applying a fixed voltage stimulus to the gate for a period of time, and then generating a time-accumulated signal. Therefore, if we refer to the voltage division connection method of the current existing work, then when the pressure stimulus and heat stimulus are applied at the same time and last for a period of time, the sensor in series with the gate will cause the gate of the electrochemical transistor to be stimulated by a fixed voltage for a period of time, and then generate a time-accumulated signal, and this accumulated signal will be combined with the source-drain current I controlled by the subsequent sensor in series with the source and drain. DS Mutual coupling cannot distinguish between pressure pain signals and heat pain signals.

[0059] Since human skin is not particularly smooth, when force stimulation and heat stimulation are performed at the same time, force stimulation is relatively faster than heat stimulation, because the speed of heat transfer is related to the contact area, temperature difference, and whether the contact is tight. However, for force stimulation, force stimulation is felt as long as there is contact, so this characteristic can also be used on electronic skin. A dynamic pressure sensor-triboelectric sensor with a shorter response time than a resistive temperature sensor is selected and connected to the gate of the transistor as a device to simulate tenderness perception neurons. Because it is a dynamic pressure sensor, when the pressure is pressed continuously, the voltage applied to the gate only exists at the moment of applying pressure. If it is not released, the negative potential part of the alternating current will not appear, so the source-drain current linear shape is a slow decrease, not a slow increase. For example Figure 5 As shown, a fixed pressure stimulus was applied to the triboelectric sensor for 10 s, but I DS If other types of sensors are used, the connection with the transistor gate is a resistor voltage divider connection, which will generate time-accumulated current and cause coupling interference to the signal superposition of the second stimulus. However, the connection between the triboelectric sensor and the transistor has no time accumulation, thereby reducing the impact on the second temperature signal.

[0060] For the resistance temperature sensor, the present invention measures the current I of the source-drain loop. DS However, the triboelectric sensor is equivalent to an open circuit and cannot be connected to the source-drain loop. Therefore, a resistive temperature sensor with a slower response time than the triboelectric sensor is selected to connect to the source-drain loop and connect it in series with the source and drain. When temperature stimulation is applied, the resistance decreases, thereby making I DS Increase, but when stimulated at the same time, the two signals will be coupled and superimposed. In order to reduce the coupling of the two signals, a circuit design is performed here. Because the resistance of the temperature sensor is about 16MΩ at room temperature, which is much larger than the channel resistance in the non-conducting state, a 500kΩ resistor is connected in parallel. First, the resistance of the entire source-drain loop is reduced, so that the initial current magnitude will not be too small to couple with the environmental noise and cause interference. Second, because the response time of the triboelectric sensor is about 80ms, and the response time of the temperature sensor is about 2s, it is necessary to ensure that the coupling interference of the temperature signal to the pressure signal is minimized within the first 80ms when stimulated simultaneously. Therefore, by connecting a small resistor in parallel, since the temperature sensor and the parallel resistance are quite different, even if the temperature sensor resistance begins to change within the first 80ms, the change in the overall parallel resistance is very small and can be ignored, that is, the total resistance change of the entire source-drain loop within the first 80ms is as small as possible, so the temperature stimulation signal generated in the first 80ms can be ignored. This can reduce the coupling effect of the temperature signal on the first section of the pressure signal, so that the temperature signal is superimposed on the pressure signal only after the pressure signal appears.

[0061] That is, the conductivity of the source and drain is regulated by gate voltage stimulation through the triboelectric sensor, the size of the parallel resistance in the source and drain circuit is regulated through the resistive temperature sensor, the dynamic response and faster response speed of the triboelectric sensor are used to reduce the impact on the temperature signal, and a small resistor is connected in parallel with the temperature sensor to reduce the overall resistance of the source and drain circuit, and the overall resistance change in the first 80ms is very small, thereby reducing the impact on the pressure signal. Therefore, the integrated signal is a superimposed signal of two segments with different slopes, the first segment is the pressure signal, and the second segment is the temperature signal, so as to distinguish the degree of stimulation and distinguish it from the signal during single stimulation to realize the recognition of the external stimulation mode.

[0062] Specific implementation process:

[0063] 1) Simulate the human skin's perception of different pressures:

[0064] like Figure 1 The equivalent circuit diagram of the pain sensing device of the present invention is shown in FIG. When the triboelectric sensor is subjected to force, different voltages are applied to the gate of the transistor, so the source-drain current I DS The size of is only affected by external force stimulation, thus simulating the perception of human skin to different force stimulations, and only in the case of high-frequency stimulation or strong stimulation I DS The pain threshold is exceeded, which simulates the pain. Since the triboelectric sensor generates a symmetrical sinusoidal AC voltage during the pressing and releasing process, the source-drain current I DS The line shape will also be a current waveform similar to alternating current, such as Figure 6 As shown, tenderness EPSCs can be distinguished from heat pain EPSCs and heat-tenderness EPSC signals.

[0065] 2) Simulate human skin's perception of different temperatures (radiant heat):

[0066] The temperature sensitive material of the resistive temperature sensor is NiO, which has a very high resistance at room temperature, making the initial source-drain loop current very small and almost non-conductive. When the temperature sensor is heated, the resistance will decrease rapidly, the resistance of the entire source-drain loop will decrease, and the loop voltage will remain unchanged, which will cause the source-drain current I DS Rapid increase, simulating thermal pain perception, and only under high temperature or continuous thermal stimulation DS The pain threshold is exceeded only when the temperature sensor is close to the source and drain circuit. This is the process of human skin feeling radiant heat stimulation. Because there is no force stimulation at this time, it can simulate the process of human skin approaching a high-temperature object but not touching it. Because the temperature sensor only performs resistance regulation in the source-drain circuit, the heat pain signal is similar to the typical EPSC signal under a positive gate voltage, such as Figure 7 As shown, EPSC signals similar to AC-shaped signals of tenderness are clearly distinguishable.

[0067] 3) Simulate the state of human skin being stimulated by heat and force at the same time (contact heat):

[0068] The triboelectric sensor and the resistive temperature sensor are stacked vertically, and force-heat stimulation is applied in the vertical direction, that is, the sensor is pressed with a heated object. Since the transfer of heat depends on the contact area, temperature difference and the tightness of the contact, force transfer is faster than heat transfer. Therefore, during force-heat stimulation, the EPSC of force stimulation will appear first, followed by the EPSC of heat stimulation. The two EPSCs are a superimposed integrated signal. Due to the different response speeds, this integrated signal is composed of two curves with different slopes, such as Figure 8 As shown. Therefore, it is easy to distinguish the degree of force stimulation and the degree of thermal stimulation from the integrated signal, so as to determine whether different types of stimulation have reached their respective pain thresholds, and then perform avoidance control. This process can also be described as a contact thermal stimulation process. The contact thermal stimulation of human skin has both force stimulation and thermal stimulation, and in the case of greater force stimulation, due to the closer contact, more heat is transferred per unit time, and the degree of damage caused is higher. Therefore, the device of the present invention can better simulate the pain signals of human skin when it is subjected to different types of stimulation, and at the same time, the external stimulation mode can be distinguished by the linear shape of EPSC.

[0069] Specific distinctions are made between line shapes: tenderness: EPSCs similar to AC signals.

[0070] Thermal pain (radiant heat): Similar to a typical positive gate voltage EPSC signal.

[0071] Heat-pressure pain (contact heat): The superposition signal of two EPSCs with different slopes.

[0072] The above is the main content of the present invention. Any changes made according to the technical solution of the present invention, when the resulting functions and effects exceed the scope of the solution of the present invention, shall belong to the protection scope of the present invention.

Claims

1. A heat-pressure pain perception device that mimics the function of human nerve synapses, characterized in that: include: The electrochemical transistor is an N-type electrolyte electrochemical transistor. The source-drain current I output by the electrochemical transistor DS Simulate the excitatory postsynaptic current EPSC of human neurons; The triboelectric sensor is connected in series with the gate of the electrochemical transistor, and different voltages are applied to the gate according to the size of the external pressure stimulus to achieve the source-drain current I of the electrochemical transistor. DS Regulation; The resistive temperature sensor is connected in series with the source and drain of the electrochemical transistor, and changes the resistance by applying temperature stimulation to realize the control of the transistor source-drain loop current I DS regulation.

2. The heat-pressure pain perception device simulating the function of human nerve synapses according to claim 1, characterized in that: One end of the triboelectric sensor is grounded, and the other end is connected to the gate of the electrochemical transistor to form a gate loop; the two ends of the resistive temperature sensor are led out through wires, one end is connected to the positive electrode of the power supply, and the other end is connected to the drain of the electrochemical transistor, and the negative electrode of the power supply is connected to the source of the electrochemical transistor to form a source-drain loop; The resistive temperature sensor is connected in parallel with a fixed-value resistor of 500 kΩ.

3. The heat-pressure pain perception device simulating the function of human nerve synapses according to claim 1, characterized in that: The electrolyte material used in the gate dielectric of the electrochemical transistor is an organic chitosan film, and the gate electrode, the source-drain electrode and the channel layer all use indium tin oxide semiconductor films.

4. The heat-pressure pain perception device simulating the function of human nerve synapses according to claim 1, characterized in that: The triboelectric sensor includes a PET substrate layer, a top Cu conductive layer, an EVA support layer, a PDMS / CaCuO6Ti2 dielectric layer, a bottom Cu conductive layer, and a PET substrate layer, which are sequentially connected from top to bottom, and the upper and lower Cu conductive layers are electrodes.

5. The heat-pressure pain perception device simulating the function of human nerve synapses according to claim 1, characterized in that: The preparation method of the triboelectric sensor is as follows: (1) preparing a PDMS solution: adding a PDMS prepolymer and a curing agent into a test tube in a mass ratio of 10:1, stirring and mixing the mixture with a glass rod, and then centrifuging the mixture in a centrifuge until the bubbles in the PDMS solution completely disappear, thereby obtaining a standby PDMS solution; (2) PDMS / CaCuO6Ti2 mixed solution: PDMS solution and CaCuO6Ti2 powder were added into a test tube in a mass ratio of 20:3, and stirred with a glass rod to obtain a PDMS / CaCuO6Ti2 mixed solution; (3) Commercial sandpaper molding: Pour the prepared PDMS / CaCuO6Ti2 mixed solution on the surface of commercial sandpaper, then place the glass plate on a spin coater for spin coating and thinning, then put it in a 60-degree oven and let it stand for 30 minutes before taking it out, and separate the prepared PDMS / CaCuO6Ti2 film from the sandpaper to obtain a PDMS / CaCuO6Ti2 dielectric layer; (4) Electrode preparation: A 50 μm copper foil was pasted on the upper and lower flexible polyethylene terephthalate films to prepare a Cu electrode, which was then led out through an enameled wire for testing; (5) Sensor assembly: The PDMS / CaCuO6Ti2Cu film was attached to the bottom Cu electrode, and a 2 mm thick EVA sponge was attached around the PDMS / CaCuO6Ti2 film as a support. The top Cu electrode was attached to the EVA sponge so that a gap was formed between the top electrode layer and the PDMS / CaCuO6Ti2Cu film. The outside was insulated and packaged with a PI film to complete the preparation of the triboelectric sensor.

6. The heat-pressure pain perception device simulating the function of human nerve synapses according to claim 1, characterized in that: The resistive temperature sensor comprises a PET substrate layer, a LIG electrode layer, a NiO temperature-sensitive layer, and a PI packaging layer which are sequentially connected from top to bottom.

7. The heat-pressure pain perception device simulating the function of human nerve synapses according to claim 6, characterized in that: The preparation method of the resistive temperature sensor is as follows: (1) Preparation of NiO ink: polyvinyl pyrrolidone powder and 1-pentanol solution were mixed at a mass ratio of 1:10, and then the obtained mixed solution was mixed with NiO nanoparticles at a mass ratio of 2:

1. The final mixed solution was ultrasonicated and stirred until the nanoparticles were completely dispersed; (2) Preparation of LIG interdigital electrodes: A commercial PI film was washed with deionized water, ethanol, and acetone, respectively, and the PI film was pasted on a 0.1 mm thick PET film. The dried PI film was laser scanned using a laser engraving machine to prepare LIG interdigital electrodes; (3) Preparation of NiO temperature-sensitive layer: The NiO temperature-sensitive layer was prepared by a drop coating method. Specifically, the prepared NiO ink was drop coated on the LIG electrode using a syringe to ensure that the edge of the LIG electrode was covered by the NiO ink. The obtained sample was naturally dried in the environment to complete the preparation of the temperature sensor.

8. The method for heat-pressure pain perception of the heat-pressure pain perception device simulating human neural synaptic function according to any one of claims 1 to 7, characterized in that: The perception process includes the following: 1) Simulate the force stimulation of human skin, i.e. tenderness: Apply different loads to the triboelectric sensor. After the force is applied to the triboelectric sensor, the distance between the upper and lower electrodes decreases; the charge is transferred between the upper and lower electrodes to generate a potential difference, which causes the voltage applied to the gate of the electrochemical transistor to increase or decrease, and the source-drain current I of the electrochemical transistor DS Generate mutations, i.e. simulate excitatory postsynaptic current EPSC, to simulate the neural electrical signal response when the skin is stimulated by force; 2) Simulate thermal stimulation of human skin, i.e. heat pain or radiant heat pain: When the resistive temperature sensor is subjected to external thermal stimulation, the resistance of the NiO temperature-sensitive layer decreases, causing the resistance of the entire source-drain loop to decrease, and the source-drain loop current I DS Increase, that is, the simulated excitatory postsynaptic current EPSC increases, realizing the neural electrical signal response when the skin is thermally stimulated; 3) Simulate the simultaneous thermal and force stimulation of human skin, i.e., heat-pressure pain or contact heat pain; The triboelectric sensor and the resistive temperature sensor are stacked vertically together. The output voltage of the triboelectric sensor and the resistance of the NiO temperature-sensitive layer are simultaneously regulated by applying force-heat stimulation from the outside, thereby regulating the gate voltage and the source-drain circuit resistance, thereby outputting the excitatory postsynaptic current EPSC when subjected to both heat and force stimulation, simulating the neural electrical signal response of the skin when subjected to both heat and force stimulation.

9. The heat-pressure pain perception method according to claim 8, characterized in that: The source-drain loop current I through the electrochemical transistor DS The excitatory postsynaptic current (EPSC) of human neurons is simulated to characterize the magnitude of stimulation on the skin. The stimulation mode is distinguished by the line shape of EPSC, and the pressure pain signal and heat pain signal are distinguished by the segmented line shape of EPSC during simultaneous stimulation. The degree of skin pressure is simulated by triboelectric sensor electrochemical transistor; The degree of skin heating is simulated by resistive temperature sensors and electrochemical transistors.

10. The heat-pressure pain perception method according to claim 9, characterized in that: When only the force stimulation of human skin is simulated: the linear shape of EPSC belongs to AC signal; When only the heat stimulation of human skin is simulated: the line shape of EPSC belongs to the typical EPSC signal under positive gate voltage; When simulating the simultaneous thermal and force stimulation of human skin: EPSC of force stimulation appears first, followed by EPSC of thermal stimulation. The linear shape of EPSC is two segments with different slopes. DS Superimposed integrated signals.

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