Multilayer bionic tactile sensor based on skin tactile perception architecture

Abstract

A multilayer bionic tactile sensor based on a skin tactile perception architecture, the sensor includes a first structural layer, a second structural layer, a third structural layer and a fourth structural layer, wherein the first structural layer is a human epidermis-like membrane layer, used to encapsulate the second structural layer, the third structural layer and the fourth structural layer; the second structural layer is a PDMS-filled fabric layer, which is seamlessly connected to the upper surface of the third structural layer, used to simulate the transmission channel of mechanical force; the third structural layer is a conductive sensitive material layer, which is used to simulate the skin tactile receptor, and is seamlessly connected to the upper surface of the fourth structural layer; the fourth structural layer is an electrode substrate, which is used to simulate the transmission ion channel. The invention has a novel structure, balances the contradiction between sensitivity and range, and enables the tactile sensor to have an ultra-wide range, higher sensitivity, shorter response time, and better stability.

Description

Technical Field

[0001] The present invention relates to a resistive flexible tactile sensor, in particular to an ultra-wide range flexible bionic tactile sensor with a multi-layer structure inspired by a human skin tactile perception architecture, belonging to the technical field of tactile sensing. Background Art

[0002] With the rapid development of flexible sensors, extensive research on wearable electronic skin has been promoted, such as human-computer interaction and health monitoring. Among them, flexible tactile sensors have received great attention in fields such as prostheses and intelligent robots. According to the different sensing mechanisms, flexible tactile sensors can be divided into resistive, capacitive, piezoelectric and triboelectric. Among them, resistive tactile sensors convert mechanical stimulation into resistance changes. It has the advantages of fast response time, convenient readout mechanism, good biocompatibility and low cost. Therefore, resistive tactile sensors have broad application prospects.

[0003] At present, when studying and pursuing high sensitivity, the research on resistive flexible tactile sensors at home and abroad needs to continuously miniaturize the internal structure of the sensor, so that the maximum pressure limit that the sensor can withstand is reduced, resulting in a small linear sensing range, and it is difficult to have high sensitivity, fast response and wide range at the same time. For example, the known CB nanoparticles made of loofah sponge can optimize the 3D wearable graphene multifunctional piezoresistive sensor with a sensitivity of 0.055 kPa -1 , with a response time of 200 ms and a linear sensing range of 300 kPa; in addition, a flexible piezoresistive sensor is fabricated by integrating graphene and carbon nanotubes for high-sensitivity tactile sensors using flexible waterborne polyurethane / cellulose nanocrystal composite aerogels with a sensitivity of 0.25 kPa. -1 , response time is 120 ms and linear sensing range is 76.16 kPa.

[0004] In summary, existing flexible resistive tactile sensors usually only have a wide linear sensing range, high sensitivity or a short response time, and it is difficult to have an ultra-wide linear sensing range, high sensitivity and fast response at the same time, which will lead to inaccurate information collection and increased difficulty in signal processing. Summary of the invention

[0005] In order to overcome the above-mentioned deficiencies in the related art, the present invention provides a multi-layer bionic tactile sensor based on skin tactile perception architecture, which has a novel structure and has the advantages of wide linear sensing range, better stability, faster response time, higher sensitivity and better flexibility.

[0006] A technical solution adopted by the present invention to solve its technical problem is:

[0007] A multi-layer bionic tactile sensor based on a skin tactile perception architecture comprises: a first structural layer, which is a membrane layer similar to human epidermis and is used to encapsulate a second structural layer, a third structural layer and a fourth structural layer; a second structural layer, which is a PDMS-filled fabric layer and is seamlessly connected to the upper surface of the third structural layer and is used to simulate a transmission channel for mechanical force; a third structural layer, which is a conductive sensitive material layer and is used to simulate a skin tactile receptor and is seamlessly connected to the upper surface of the fourth structural layer; and a fourth structural layer, which is an electrode substrate and is used to simulate a transmitted ion channel.

[0008] Another technical solution adopted by the present invention to solve its technical problem is:

[0009] A method for preparing a multilayer bionic tactile sensor based on a skin tactile perception architecture comprises the following steps: preparing a conductive sensitive material layer: treating paper with a NaOH aqueous solution and a CB-MXene-SR two-phase sensitive material solution in sequence; preparing a PDMS filled fabric layer: immersing the fabric in PDMS for treatment; stacking and connecting the PDMS filled fabric layer, the conductive sensitive material layer and the interdigital electrode substrate from top to bottom, and then encapsulating them with a breathable and waterproof film.

[0010] Compared with the related art, the multi-layer bionic tactile sensor based on the skin tactile perception architecture of the present invention has at least four structural layers. The first structural layer is used to simulate the human epidermis and is completely surrounded by the outside of other structural layers. Then the PDMS-filled fabric layer of the second structural layer simulates the ion channel through which mechanical force is transmitted to the tactile receptor. The loose and porous characteristics of the fabric are used to construct a concave-convex microstructure. At the same time, the porous gaps between the fabrics are filled with superelastic PDMS, so that the fabric has a good ability to transmit mechanical force, and then contacts with the third structural layer, thereby increasing the sensitivity of the tactile sensor. Since the third structural layer adopts a conductive sensitive material layer, it simulates the skin tactile receptor, and can directly act on the first structural layer and convert the mechanical force transmitted through the second structural layer into changes in electrical parameters, and the changes are linear and stable. The conductive sensitive material layer itself has good electrical properties. The interdigitated electrode substrate of the fourth structural layer simulates the transmitted ion channel.

[0011] It can be seen that based on the above structure, compared with the traditional tactile sensor structure, under the same size conditions, the sensor of the embodiment of the present invention has a super high linear sensing range, and has the characteristics of high sensitivity, short response time, good stability, etc. Since the change in resistance value can reflect the magnitude of the force applied to the sensor, it provides accurate and timely feedback for human-machine interaction and intelligent robots, so the sensor of the embodiment of the present invention has excellent performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0013] Figure 1a It is a schematic diagram of the structure of a sensor according to an embodiment of the present invention.

[0014] Figure 1b It is a structural explosion diagram of a sensor according to an embodiment of the present invention.

[0015] Figure 2a Schematic diagram of the structure of the PDMS filled fabric layer in one embodiment of the present invention.

[0016] Figure 2b 1 is an exploded view of the structure of the PDMS filled fabric layer in one embodiment of the present invention.

[0017] Figure 3a Schematic diagram of the structure of an interdigitated electrode substrate in one embodiment of the present invention.

[0018] Figure 3b 1 is an exploded view of the structure of the interdigitated electrode substrate in one embodiment of the present invention.

[0019] Figure 3c 1 is an exploded view of the structure of the interdigital electrodes in one embodiment of the present invention.

[0020] Figure 4 It is a schematic diagram of a process for preparing a sensor according to an embodiment of the present invention.

[0021] Figure 5 It is a schematic diagram of two-dimensional stress distribution of a sensor in three different pressure stages according to an embodiment of the present invention.

[0022] Figure 6a , Figure 6b , Figure 6c Schematic diagrams of paper, paper treated with NaOH aqueous solution, and paper treated with CB-MXene-SR two-phase sensitive material solution at 5 nm, 50 nm, and 500 nm resolutions under a scanning electron microscope, respectively.

[0023] Figure 7 It is a schematic diagram of the relationship between the relative resistance change and pressure of a sensor according to an embodiment of the present invention.

[0024] Figure 8 Schematic diagram of current-voltage (IV) curves of a sensor under different pressure conditions according to an embodiment of the present invention.

[0025] Fig. 9 FIG. 4 is a response curve of a sensor according to an embodiment of the present invention when detecting an ultralight object (0.28 g).

[0026] Fig.10 This is a test curve of the response time of a sensor according to an embodiment of the present invention.

[0027] Fig.111 is a periodic pressure and response curve of a sensor according to an embodiment of the present invention.

[0028] Fig.12 It is a temperature interference test diagram of a sensor according to an embodiment of the present invention.

[0029] Fig.13 The figure is a relative resistance change curve of a sensor according to an embodiment of the present invention when loaded at 0.25 Hz, 0.5 Hz and 1 Hz.

[0030] Fig.14 1 is a stress-strain curve of a sensor according to an embodiment of the present invention when cyclically loaded / unloaded under different strain conditions.

[0031] Fig.15 The figure shows the response stability of a sensor according to an embodiment of the present invention at different curvature radii.

[0032] Fig.16 This is a stability test curve of a sensor according to an embodiment of the present invention during a 17 kPa pressure loading / unloading process.

[0033] Fig.17a , 17b 17c are the relative resistance change curves of a sensor integrated on a glove grasping a beaker containing 50 ml of mung beans, water and sand according to an embodiment of the present invention.

[0034] In the figure: 1, first structural layer, 2, second structural layer, 21, modal fabric skeleton, 22, PDMS filler, 3, third structural layer, 4, fourth structural layer, 42, substrate, 41, interdigitated electrode, 411, interdigitated electrode port, 412, interdigitated rod, 413, wire. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] Figure 1 to Figure 7 FIG. 1 is a schematic diagram showing a structure of a preferred embodiment of the present invention. Figure 1a , 1b A multi-layer bionic tactile sensor based on skin tactile perception architecture, comprising a first structure layer, a second structure layer, a third structure layer and a fourth structure layer, wherein:

[0037] The first structural layer is a human epidermis-like membrane layer. In this embodiment, the human epidermis-like membrane layer is a breathable and waterproof film. Specifically, the breathable and waterproof film may include a polytetrafluoroethylene film or a thermoplastic polyurethane.

[0038] The second structural layer is a PDMS filled fabric layer, refer to Figure 2a , 2b In this embodiment, the PDMS-filled fabric layer is mainly composed of a modal fabric skeleton and a PDMS filler, and the PDMS filler is arranged in the gap of the modal fabric skeleton. The PDMS-filled fabric layer is used to simulate the transmission channel of the mechanical force, and the loose and porous characteristics of the fabric are used to construct a concave-convex microstructure, which contacts with the third structural layer to increase the sensitivity of the tactile sensor. In other preferred embodiments, the modal fabric can be replaced by other chemical fiber fabrics, such as nylon fabric, etc., and can also be replaced by other types of fabrics, including cotton fabrics, wool fabrics, silk fabrics, linen fabrics, and blended fabrics.

[0039] The third structural layer is a conductive sensitive material layer, which is used to simulate the skin tactile receptors and convert mechanical force into changes in electrical parameters; in this specific embodiment, the conductive sensitive material layer is paper treated with NaOH aqueous solution and CB (carbon black)-MXene (meckelene)-SR (silicone rubber) two-phase conductive material solution in sequence. In this embodiment, the skin tactile receptors simulate Meissner's corpuscles, and can also simulate Ruffini's corpuscles, Merkel's discs or Pacinian corpuscles and other tactile receptors.

[0040] The fourth structural layer is an electrode substrate, which is used to simulate the ion channel of the transmission. In this embodiment, the electrode substrate is an interdigitated electrode substrate. Figure 3a , 3b , 3c, specifically mainly composed of a substrate, interdigital electrodes and wires, wherein the interdigital electrodes further include interdigital electrode ports and interdigital rods, a pair of interdigital electrode ports are arranged facing each other, a plurality of interdigital rods are fixedly connected to one side of the interdigital electrode ports, the interdigital rods on the two interdigital electrode ports are arranged in an interdigital manner, and a wire is arranged on each interdigital electrode port. In the specific implementation of this embodiment, the substrate 42 is made of polyimide (PI for short), because PI has excellent insulation and elasticity, the materials of the wire 413 and the interdigital electrode 41 include gold, silver or copper, etc., and the wire 43 can be adhered to the interdigital electrode port by conductive silver glue.

[0041] The first structure layer, the second structure layer, the third structure layer, and the fourth structure layer are stacked from top to bottom, the second structure layer is connected to the upper surface of the third structure layer without gaps by means of tight bonding, etc., the third structure layer is connected to the upper surface of the fourth structure layer without gaps by means of tight bonding, etc., the first structure layer encapsulates the second structure layer, the third structure layer, and the fourth structure layer (refer to Figure 1b).

[0042] As a specific implementation scheme, in an embodiment of the present invention, the length and width of the second structural layer and the third structural layer are equal, and they maintain vertical symmetry. The overall structure of the second structural layer and the third structural layer is a rectangular parallelepiped, and can also be any one of a prism, a prism or a bionic structure. Furthermore, the second layer 2 and the third layer 3 are both solid structures. An ultra-wide range flexible bionic tactile sensor based on a multi-layer structure inspired by the tactile perception architecture of human skin is prepared, which can be used for electronic skin and wearable electronic devices.

[0043] Reference Figure 4 A method for preparing a multilayer bionic tactile sensor based on a skin tactile perception architecture according to an embodiment of the present invention comprises at least the following steps: preparing a conductive sensitive material layer: treating paper with a NaOH aqueous solution and a CB-MXene-SR two-phase sensitive material solution in sequence; preparing a PDMS filled fabric layer: immersing the fabric in PDMS for treatment; stacking and connecting the PDMS filled fabric layer, the conductive sensitive material layer and the interdigital electrode substrate from top to bottom, and then encapsulating them with a breathable and waterproof film.

[0044] In this specific embodiment, the preparation process is as follows:

[0045] 1) preparing an interdigitated electrode substrate;

[0046] 2) Preparation of conductive sensitive material layer: The paper is treated with NaOH aqueous solution and CB-MXene-SR two-phase sensitive material solution in sequence;

[0047] 3) Preparation of PDMS filled fabric layer: The fabric is immersed in PDMS, wherein the PDMS solution is prepared by mixing silicone resin and curing agent in a weight ratio of 10:1;

[0048] 4) Select a breathable and waterproof film;

[0049] 5) The PDMS-filled fabric layer, the conductive sensitive material layer and the interdigital electrode substrate are stacked and connected from top to bottom, and then encapsulated with a breathable and waterproof film.

[0050] In the specific scheme of step 1) of the embodiment of the present invention, the preparation of the interdigitated electrode substrate is to use polyimide (PI for short) as a flexible substrate, use gold foil to plate on the flexible substrate to form interdigitated gold electrodes, and use conductive silver glue (YC-02, A:B=10:1) to adhere the gold wire to the interdigitated gold electrode port.

[0051] In the specific scheme of step 2) of the embodiment of the present invention, the preparation process of the conductive sensitive material layer is as follows: first prepare a NaOH aqueous solution, add sodium hydroxide (20%) into deionized water, stir and dissolve to obtain a NaOH aqueous solution; after the paper is washed with deionized water and dried, place it in the NaOH aqueous solution for 5 minutes, wherein the drying method can be treated in an oven at 40°C for 0.5 hours, and the remaining sodium hydroxide on the surface of the paper fiber is removed with deionized water, and dried, wherein the drying treatment is an oven at 40°C for 0.5 hours to obtain the paper treated with the NaOH aqueous solution; the paper treated with the above-mentioned NaOH aqueous solution is added to the CB-MXene-SR two-phase sensitive material solution for ultrasonic dispersion for 1 hour and magnetic stirring for 2 hours, wherein the CB-MXene-SR two-phase sensitive material solution is obtained as follows: 1:1 (9wt%), 0.045g CB, 0.045g MXene, 1g SR, and the solvent is n-hexane; after impregnation, drying treatment (oven, 40°C, 8 hours) is performed to obtain the sensitive material treated paper, that is, the conductive sensitive material layer.

[0052] In the specific scheme of step 3) of the embodiment of the present invention, the PDMS filled fabric layer is prepared by immersing the modal fabric in PDMS for 5 min and drying it in an oven at 80° C. for 2 h.

[0053] This embodiment is a multilayer bionic tactile sensor based on the skin tactile perception architecture prepared according to the above preparation method. In a preferred embodiment, the total area of ​​the PI substrate 42 is 1 cm×1 cm, the interdigital rods 411 are 0.1 cm×0.9 cm, the spacing between the interdigital rods 411 is 0.8 cm, the length of the interdigital rods is 0.7 cm, there are a total of 16 interdigital rods on both sides, and the area of ​​the interdigital region is 0.7 cm×0.5 cm. This preferred solution is to obtain an optimized interdigital electrode substrate based on previous research to improve the performance of the sensor.

[0054] The embodiments of the present invention are designed based on the inspiration of the human skin tactile perception architecture: human skin is an extremely complex somatosensory system, including components of the epidermis and dermis. Many receptors covered by the epidermis, such as Meissner's bodies, can detect static and dynamic tactile stimuli. Ion channels can effectively transmit stimuli to the tactile receptors of the skin. There are also abundant neurons in the dermis that collect information from receptors and send them to the cerebral cortex for tactile perception. The special layered structure gives human skin high-performance full-range pressure detection capabilities.

[0055] The sensor of the embodiment of the present invention has accurate perception, novel structure and enhanced performance, which not only balances the contradiction between sensitivity and range, but also enables the tactile sensor to have an ultra-wide range, higher sensitivity, shorter response time and better stability. Please refer to the specific Figure 5- Figure 17 Test verification process and analysis:

[0056] Figure 5 The figure shows the two-dimensional finite element simulation results of the sensor of the embodiment of the present invention based on COMSOL. The figure shows the two-dimensional stress distribution. The simulation image verifies the deformation of the medium layer at three different pressure stages after the sensor is stressed. It is not difficult to see that as the applied pressure increases, the PDMS-filled modal fabric will transfer the pressure to the two-phase conductive sensitive material layer, thereby generating the maximum stress.

[0057] Figure 6a , 6b 6c are schematic diagrams of 5 nm, 50 nm and 500 nm resolution of scanning electron microscope, respectively, for paper, paper treated with NaOH aqueous solution and paper treated with CB-MXene-SR two-phase sensitive material solution, which can only be expressed in the form of color photos. Figure 6a As shown in Figure 2, it can be clearly seen that the bare paper presents an irregular striped skeleton with burrs. After the bare paper is treated in NaOH aqueous solution, Figure 6b As shown, the burrs of the irregular striped skeleton on the paper surface are removed, and the skeleton becomes smooth. The circle in the figure shows that the modification treatment is beneficial to the separation between different fiber skeletons and increases the specific surface area. On the other hand, the number of wrinkled structures on a single fiber increases. Both aspects are beneficial to the combination of the composite conductive material and the substrate. The paper treated with NaOH aqueous solution is dried and placed in a CB-MXene-SR two-phase sensitive material solution. Since CB and MXene are randomly distributed in the SR matrix, the combination and entanglement of CB and MXene help to form a stable conductive network. In addition, Figure 6c The mixed solution was uniformly filled in the gap between the paper frames, indicating that the two-phase sensitive materials were successfully loaded into the gap. Figure 6c The second picture shows the outline of MXene. This phenomenon will play an important role in the performance of the sensor and help improve the conductivity and mechanical properties of the sensor.

[0058] Figure 7 The sensitivity curve of the sensor of the embodiment of the present invention is mainly divided into three stages: the first stage is from 0 Pa to 15 kPa, and the sensitivity is about 2.18 kPa -1 ; The second stage is from 1 kPa to 1400 kPa, with a sensitivity of about 0.032 kPa -1 ; The third stage is between 1400 kPa and 1700 kPa, with a sensitivity of about 0.00059 kPa -1 The experimental results prove the feasibility and performance of the structure. Compared with the traditional tactile sensor, this structure not only has high sensitivity but also has a wide linear sensing range.

[0059] Figure 8 The current-voltage (IV) curve of the sensor of the embodiment of the present invention under different pressure conditions. In order to further confirm the reliability of the sensor, the sensitive parameters of the sensor were analyzed. The current-voltage (IV) characteristic curve of the tactile sensor strictly complies with Ohm's law. Under different pressures, as the applied pressure increases, the resistance decreases accordingly, and its slope also increases accordingly, indicating that the sensor has excellent reliability during the compression process.

[0060] Fig. 9 This is the response curve when the embodiment of the present invention is applied to detect ultra-light objects. When an object with a weight of 0.28 g is loaded, the resistance response curve is clearly visible, and the result shows that the tactile sensor can detect a slight pressure change of 200 Pa. It can be seen from the curve that when an object is placed on the sensor surface, its output resistance value changes instantly, and the result remains in a stable value range, indicating that the sensor has good reliability in high-resolution tactile perception applications.

[0061] Fig.10 The response time test curve of the sensor of the embodiment of the present invention is shown in Figure 1. When the loading / unloading pressure of the tactile sensor is 485 kPa, the sensor exhibits a fast response time of 100 ms and a recovery time of 100 ms, indicating that the prepared tactile sensor has fast response / recovery characteristics. Therefore, this ensures that the sensor has an instantaneous sensing capability similar to that of human skin.

[0062] Fig.11 The following are the periodic pressure and response curves of the sensor according to the embodiment of the present invention. When periodic pressures of 230 kPa, 110 kPa and 13.5 kPa are applied to the sensor, there is an obvious matching relationship between the pressure output and the response curve.

[0063] Fig.12 This is a temperature interference test diagram of the sensor of the embodiment of the present invention. From the experimental data, it is obtained that the maximum interference effect of temperature on the sensor is 0.08, indicating that temperature has little effect on the sensing characteristics of the sensor proposed in the present invention.

[0064] Fig.13 The following is the relative resistance change curve of the sensor of the embodiment of the present invention at different loading frequencies. The sensor changes at frequencies of 0.25 Hz, 0.5 Hz and 1 Hz. The results show that the sensor can accurately detect the peak value of each cycle. In addition, the peak value of each frequency is very stable.

[0065] Fig.14The stress-strain curve of the sensor of the embodiment of the present invention under cyclic loading / unloading conditions under different strain conditions. The image shows that when the compressive strain of the sensor is less than 10%, the stress in the linear elastic region increases rapidly. When the compressive strain further increases to 80%, a dense area with a sharp increase in stress appears. This shows that each layer has a certain energy dissipation capacity and high mechanical resilience. As a wearable electronic product, the sensor must have toughness and fatigue resistance.

[0066] Fig.15 The response stability of the sensor of the embodiment of the present invention at different curvature radii. To evaluate the response stability of the sensor at different bending radii, the sensor was bent and attached to plastic cylinders of different diameters, and the relative resistance of the sensor was observed to change with the applied pressure. The results in the figure show that the signal amplitude of the sensor remains basically unchanged at different curvature radii. Therefore, tactile sensors are expected to be used in human joint monitoring.

[0067] Fig.16 The sensor of the embodiment of the present invention was dynamically loaded / unloaded for 5000 cycles at a pressure of 17 kPa, and the response curve of the tactile sensor was obtained in real time. The relative resistance of the sensor is basically stable and the response performance is good. The illustrations are the 1000th to 1005th and 4000th to 4005th cycles of loading, respectively. The image waveforms and amplitudes are very similar, indicating that the sensor has excellent stability and durability, and has outstanding potential in high-precision, long-term pressure monitoring applications.

[0068] The sensor of the embodiment of the present invention lights up the LED in the manufactured circuit application. In order to intuitively verify the resistance change of the sensor during compression, the LED lighting experimental device connects the sensor and LED in series and applies voltage. In a bright environment, the LED light is weak under no-load conditions, which means that the sensor has high conductivity and low operating voltage. When the load on the sensor increases from 50 g, 100 g, 200 g and 500 g, the light intensity of the LED gradually increases. The results intuitively show that the resistance of the sensor of the embodiment of the present invention decreases with the increase of pressure. After removing the load, the final brightness of the LED is the same as the initial brightness, indicating that the conductive network of the sensor returns to its original state after the pressure is released, proving its excellent stability.

[0069] Fig.17a , 17b17c respectively show that the relative resistance of the tactile sensor of the embodiment of the present invention fixed on the latex glove will change when the hand picks up a beaker containing 50 ml mung beans, water and sand. Take the 50 ml beaker as the carrier and grasp the beaker in three different situations. Repeat 6 times when grasping the beaker with fingers to obtain relatively reliable data. The relative resistance signal response and recovery process represent the bending and opening states of the fingers during the grasping process, respectively. Different signal changes represent the strength of the fingers during the grasping process. The relative resistance will change in the six cycles of grasping and releasing the beaker. Remain quite stable. Since the beaker containing mung beans is light, the relative resistance does not change much when the fingers grasp it. The beaker containing pure water is an object of medium mass, and the relative resistance changes greatly during the finger grasping process. The beaker containing sand has the heaviest mass, and the relative resistance signal changes most significantly during the finger grasping process. In summary, the experimental results show that the designed flexible tactile sensor has precise tactile feedback and fast response characteristics, providing an efficient, novel and low-cost solution for data gloves, intelligent robots, and human-computer interaction.

[0070] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification and equivalent changes made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A multi-layer bionic tactile sensor based on skin tactile perception architecture, characterized in that: include: The first structural layer is a membrane layer similar to human epidermis, and is used to encapsulate the second structural layer, the third structural layer and the fourth structural layer; The human epidermis-like membrane layer is a breathable and waterproof film, wherein the breathable and waterproof film comprises a polytetrafluoroethylene film or a thermoplastic polyurethane; The second structural layer is a PDMS-filled fabric layer, which is connected to the upper surface of the third structural layer without a gap, and is used to simulate the transmission channel of the mechanical force. The loose and porous characteristics of the fabric are used to construct a concave-convex microstructure, which is in contact with the third structural layer to increase the sensitivity of the tactile sensor; the PDMS-filled fabric layer is mainly composed of a fabric skeleton and a PDMS filler, and the PDMS filler is arranged in the gap of the fabric skeleton; The third structural layer is a conductive sensitive material layer used to simulate the skin tactile receptors and is seamlessly connected to the upper surface of the fourth structural layer; The conductive sensitive material layer is paper treated with a NaOH aqueous solution and a CB-MXene-SR two-phase conductive material solution in sequence; and a fourth structural layer, which is an electrode substrate, used to simulate the ion channel for transmission; The steps of preparing the multilayer bionic tactile sensor include: preparing a conductive sensitive material layer: treating paper with a NaOH aqueous solution and a CB-MXene-SR two-phase sensitive material solution in sequence; In the CB-MXene-SR two-phase sensitive material solution, CB, MXene, and SR are 0.045 g, 0.045 g, and 1 g, respectively, the solvent is n-hexane, and the mass percentage of CB+MXene is 9%; a PDMS-filled fabric layer is prepared by immersing the fabric in PDMS, wherein the PDMS solution is prepared by mixing a silicone resin and a curing agent in a weight ratio of 10:1; the PDMS-filled fabric layer, the conductive sensitive material layer, and the interdigital electrode substrate are stacked and connected from top to bottom, and then encapsulated with a breathable and waterproof film.

2. The multi-layer bionic tactile sensor based on skin tactile perception architecture according to claim 1 is characterized by: The fabrics include cotton fabrics, wool fabrics, silk fabrics, linen fabrics, chemical fiber fabrics, and blended fabrics, wherein the chemical fiber fabrics include modal fabrics and nylon fabrics.

3. The multi-layer bionic tactile sensor based on skin tactile perception architecture according to claim 1, characterized in that: The electrode substrate is an interdigitated electrode substrate, which is mainly composed of a substrate, interdigitated electrodes and wires, wherein the interdigitated electrodes include interdigitated electrode ports and interdigitated rods, a pair of interdigitated electrode ports are arranged facing each other, a plurality of interdigitated rods are fixedly connected to one side of the interdigitated electrode ports, the interdigitated rods on the two interdigitated electrode ports are arranged in an interdigitated manner, and a wire is arranged on each interdigitated electrode port.

4. A multi-layer bionic tactile sensor based on skin tactile perception architecture according to claim 1 or 2, characterized in that: The overall structures of the second structural layer and the third structural layer are any one of a cuboid, a prism, a prism or a bionic structure.

5. A multi-layer bionic tactile sensor based on skin tactile perception architecture according to claim 1 or 2, characterized in that: The skin touch receptors include Meissner's corpuscles, Ruffini's corpuscles, Merkel's discs or Pacinian's corpuscles.

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