A biomimetic flexible tactile sensor array and a method of manufacturing the same

Abstract

The application discloses a kind of bionic flexible tactile sensor array and preparation method thereof, it is related to flexible tactile sensing technical field, including flexible single electrode, pressure-sensitive conductive layer, bionic structure layer, buffer layer and flexible array electrode, the surface of pressure-sensitive conductive layer is spaced array distribution with multiple protrusions, bionic structure layer is provided with bionic structure corresponding protrusion, protrusion is embedded inside bionic structure and in unforced state, the end face of protrusion and the end face of bionic structure exist preset gap.The application adopts pressure-sensitive conductive layer and bionic structure layer nested initial gap design, forms threshold trigger type conductive path, sensor is isolated completely with pressure-sensitive conductive layer when not subjected to external force, sensor is in zero power consumption standby state, unlike traditional always-on type piezoresistive sensor, significantly reduce static power consumption;At the same time, avoid the problem of effective sensitivity early loss caused by pre-compression of traditional sensor from the root, guarantee the sensitivity stability in full range.

Description

Technical Field

[0001] This invention relates to the field of flexible tactile sensing technology, and more specifically, to a biomimetic flexible tactile sensor array and its fabrication method. Background Technology

[0002] Flexible sensors, as core sensing devices in human-computer interaction, intelligent robots, and wearable devices, have received widespread attention in recent years. Resistive tactile sensors achieve force-sensitive response based on the piezoresistive effect or the principle of changes in interface contact resistance.

[0003] However, most existing resistive tactile sensors are in an on state in the initial state. Their sensitive layer microstructures (such as pyramids, micropillars, porous structures, etc.) have already undergone local pre-compression deformation when not subjected to external load, causing the effective sensitivity of the sensor to be lost before it works, and causing energy loss. In many practical application scenarios, flexible sensors do not need to be in an on state at all times, and the existing structural design is obviously not compatible with the actual working conditions. For example: (1) When a robot is grasping, the robotic arm or manipulator does not need to sense pressure during idle movement, and only needs to generate a signal when grasping an object; (2) In a smart cushion / mattress, when no one sits down, the sensor is in an "open circuit" or extremely high resistance state, and the system is in sleep mode. Only when a person sits down and the pressure exceeds the design threshold is the system turned on and awakened to detect posture, heart rate, etc.; (3) In a flexible array keyboard, no power is needed when the key is not pressed, and only when it is pressed does it need to respond. These scenarios clearly demonstrate that in practical applications, initial conduction tactile sensors can cause problems such as sensitivity loss and energy loss. Therefore, there is an urgent need to provide a threshold-triggered conductive path control strategy. Summary of the Invention

[0004] To address the aforementioned technical challenges, the present invention aims to provide a biomimetic flexible tactile sensor array and its fabrication method, thereby resolving the technical problems in the background art. By combining innovative structural design with a threshold-triggered conductive path control strategy, the sensor achieves high sensitivity and eliminates static power consumption to meet practical application scenarios.

[0005] The specific plan is as follows: The first aspect of this invention provides a biomimetic flexible tactile sensor array, comprising, from top to bottom: A flexible single electrode includes a flexible substrate and a common electrode disposed on the surface of the flexible substrate; The pressure-sensitive conductive layer is composed of an elastic matrix and conductive fillers dispersed in the elastic matrix. Multiple protrusions with the same structure are distributed in an array at intervals on the surface of the pressure-sensitive conductive layer. A biomimetic structure layer has a biomimetic structure on its surface corresponding to the protrusion. The biomimetic structure has a through-hole. The protrusion is embedded in the through-hole of the biomimetic structure. In the unstressed state, there is a preset gap between the end face of the protrusion and the end face of the biomimetic structure. The buffer layer is a hollow frame structure with a thickness that matches the height of the biomimetic structure. The biomimetic structure is inserted into the hollow part of the buffer layer to achieve the interlocking and cooperation between the biomimetic structure layer and the buffer layer. The flexible array electrode includes a flexible substrate and multiple independent electrode units, with each electrode unit corresponding to a protrusion in the piezoresistive conductive layer. When subjected to force, each biomimetic structure and buffer layer undergoes compressive deformation, causing the protrusions corresponding to the biomimetic structure to come into contact with the electrode unit and conduct electricity, generating a change in resistance and realizing pressure sensing. After the force is removed, each component returns to its original configuration.

[0006] Preferably, the biomimetic structure is an octopus sucker-like structure.

[0007] Preferably, the flexible substrate of the flexible single electrode and the flexible matrix of the flexible array electrode are made of PET or PI material, and the common electrode and electrode unit are selected from any one of silver paste / silver-based nano-conductive ink, copper-based nano-conductive ink, graphene ink, carbon nanotube ink, liquid metal ink or poly(3,4-ethylenedioxythiophene):polystyrene sulfonate ink.

[0008] Preferably, the pressure-sensitive conductive layer has a porous structure and is composed of polydimethylsiloxane and carbon nanotubes.

[0009] Preferably, the ratio of polydimethylsiloxane precursor to curing agent in the polydimethylsiloxane is 10:1.

[0010] Preferably, the pressure-sensitive conductive layer is prepared by the sacrificial salt template method to form a porous structure, wherein the amount of NaCl added is 10% to 30% of the mass of the polydimethylsiloxane precursor.

[0011] Preferably, the biomimetic structure layer includes a substrate structure, the biomimetic structure is integrated on the substrate structure, and the modulus of the biomimetic structure is lower than that of the substrate structure.

[0012] Preferably, the biomimetic structural layer is made of polydimethylsiloxane, the ratio of polydimethylsiloxane precursor to curing agent in the biomimetic structure is 12.5:1, and the ratio of polydimethylsiloxane precursor to curing agent in the substrate structure is 7.5:1.

[0013] Preferably, the buffer layer has a porous sponge structure and is made of polyurethane or melamine.

[0014] A second aspect of the present invention provides a method for fabricating a biomimetic flexible tactile sensor array as described in the first aspect of the present invention, comprising the following steps: S1, Fabrication of flexible single electrodes and flexible array electrodes: Flexible single electrodes and flexible array electrodes are fabricated using ink direct writing or inkjet printing technology, and leads are drawn out; S2, Preparation of pressure-sensitive conductive layer: A porous structure composed of conductive filler and elastomer polymer is prepared by using 3D printing template molding process combined with sacrificial salt template method to obtain a pressure-sensitive conductive layer with multiple protrusions on the surface. S3, Preparation of biomimetic structural layer: Using 3D printing template molding process, an octopus sucker-like structure is prepared using elastomer polymer as raw material to obtain a biomimetic structural layer; S4, Prepare the buffer layer: Cut the porous sponge structure into a hollow frame structure of a preset size to obtain the buffer layer; S5, Overall Packaging: The above-mentioned flexible single electrode, pressure-sensitive conductive layer, biomimetic structure layer, buffer layer, and flexible array electrode are aligned in order from top to bottom and then packaged as a whole to complete the fabrication of the biomimetic flexible tactile sensor array.

[0015] The beneficial effects of this invention are as follows: (1) This invention provides a threshold-triggered conductive path control strategy. By innovatively designing an octopus suction cup structure and adopting a nested initial gap design of pressure-sensitive conductive layer and biomimetic structural layer, a threshold-triggered conductive path is formed. When the sensor is not subjected to external force, the electrode unit is completely isolated from the pressure-sensitive conductive layer, and the sensor is in a zero-power standby state. This is different from the traditional normally-continuous piezoresistive sensor and significantly reduces static power consumption. At the same time, it avoids the problem of premature loss of effective sensitivity caused by pre-compression of traditional sensors from the root cause and ensures the stability of sensitivity throughout the entire range. (2) From electrode preparation to the molding of each functional layer, the present invention adopts advanced printing technology. The structural parameters can be precisely controlled, which facilitates mass production and performance optimization. The flexible array electrodes correspond one-to-one with the columnar protrusions and biomimetic structures to form a high-density sensing array, which can realize the acquisition of tactile signals with multiple points and high spatial resolution, and is suitable for complex curved surfaces and multi-touch sensing scenarios such as robot tactile perception and wearable health monitoring. Attached Figure Description

[0016] Figure 1 This is a schematic diagram showing the overall structure of the biomimetic flexible tactile sensor array of the present invention.

[0017] Figure 2 This is a schematic diagram of the biomimetic structural layer of the biomimetic flexible tactile sensor array of the present invention.

[0018] Figure 3 This is a diagram showing the structural relationship between the pressure-sensitive conductive layer and the biomimetic structural layer of the biomimetic flexible tactile sensor array of the present invention.

[0019] Figure 4This is a schematic diagram of the electrode unit of the flexible array of the biomimetic flexible tactile sensor array of the present invention.

[0020] Figure 5 This is a structural diagram of the integrated biomimetic flexible tactile sensor array of the present invention.

[0021] Figure 6 This is a partial assembly cross-sectional view of the biomimetic flexible tactile sensor array of the present invention.

[0022] The reference numerals in the appendix of this invention are as follows: 1. Flexible single electrode; 2. Pressure-sensitive conductive layer; 3. Bionic structure layer; 4. Buffer layer; 5. Flexible array electrode. Detailed Implementation

[0023] The technical solutions of the present invention will now be clearly and completely described with reference to the accompanying drawings in the embodiments of the present invention.

[0024] Please see Figure 1 The biomimetic flexible tactile sensor array disclosed in this embodiment includes, from top to bottom, a flexible single electrode 1, a pressure-sensitive conductive layer 2, a biomimetic structural layer 3, a buffer layer 4, and a flexible array electrode 5.

[0025] The flexible single electrode 1 comprises a flexible substrate and a common electrode disposed on the surface of the flexible substrate. The flexible substrate is a flat plate structure with a length and width of 30 mm and 20 mm, respectively, and is made of polyethylene terephthalate (PET) or polyimide (PI) with a thickness of 100~200 µm. The common electrode is located at the center of the flexible substrate, arranged in a rectangle on one surface of the flexible substrate, and has a size of 25 mm × 15 mm. The material of the common electrode is selected from any one of silver paste / silver-based nano-conductive ink, copper-based nano-conductive ink, graphene ink, carbon nanotube ink, liquid metal ink, or poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) ink.

[0026] The pressure-sensitive conductive layer 2 has a porous structure, consisting of an elastic matrix and conductive fillers dispersed within it. The elastic matrix is ​​a flat plate structure, with its upper surface tightly bonded to the flexible single electrode 1, and its lower surface having multiple identical columnar protrusions arranged in an array at intervals. The elastic matrix is ​​made of polydimethylsiloxane (PDMS), with a PDMS precursor-to-curing agent ratio of 10:1. The conductive filler is made of carbon nanotubes (CNTs), with a CNT mass fraction of 0.3%–0.6%. The pressure-sensitive conductive layer 2 macroscopically features columnar protrusions fabricated using a 3D printing template method, and microscopically forms a porous structure using a sacrificial salt template method, where the amount of NaCl added is 10%–30% of the mass of the PDMS precursor. The overall thickness of the pressure-sensitive conductive layer 2 is 2.25 mm, with the columnar protrusions having a height of 1.75 mm and a diameter of 2.5 mm. The elastic matrix has dimensions of 30 mm × 20 mm × 0.5 mm.

[0027] Please see Figure 2 and Figure 3 The biomimetic structure layer 3 consists of a substrate structure and biomimetic structures arranged in an array on the lower surface of the substrate structure. The substrate structure is a rectangular plate with dimensions of 30mm × 20mm × 0.5mm. The biomimetic structures correspond one-to-one with the protrusions of the pressure-sensitive conductive layer 2, with each biomimetic structure embedding one protrusion, forming a precisely nested array structure. The overall thickness of the biomimetic structure layer 3 is 2mm, with the height of the biomimetic structures being 1.5mm. The biomimetic structures resemble octopus suction cups, with their outer sidewalls tilted outwards at an angle and a through-hole in the center. After encapsulation, the protrusions of the pressure-sensitive conductive layer 2 are embedded in the through-hole of the biomimetic structure, and in the unloaded state, there is a predetermined gap between the end face of the protrusion and the end face of the biomimetic structure. The biomimetic structure layer 3 is fabricated using a 3D printing template molding process and is made of polydimethylsiloxane (PDMS). Its overall design exhibits a gradient modulus distribution, with a harder upper layer and a softer lower layer to achieve efficient tactile sensing. Specifically, the modulus of the biomimetic structure is lower than that of the substrate structure. The biomimetic structure, made of PDMS with a precursor-to-curing agent ratio of 12.5:1, is more easily compressed and deformed, promoting full contact between the pressure-sensitive conductive layer 2 and the flexible array electrode 5. The substrate structure, made of PDMS with a precursor-to-curing agent ratio of 7.5:1, acts as a support layer to constrain excessive deformation and ensure structural stability.

[0028] The buffer layer 4 is a porous sponge structure, with an overall shape resembling a frame with rectangular cutouts, measuring 30mm × 20mm. These rectangular cutouts, measuring 25mm × 15mm, allow the biomimetic structure to pass through, enabling the interlocking of the biomimetic structure layer 3 and the buffer layer 4. The buffer layer 4 is made of polyurethane or melamine, used for stress dissipation and flexible adaptation. Its thickness, 1.5mm, matches the height of the biomimetic structure, ensuring initial isolation between the pressure-sensitive conductive layer 2 and the flexible array electrode 5.

[0029] Please see Figure 4 The flexible array electrode 5 includes a flexible substrate and multiple independent electrode units arranged on the upper surface of the flexible substrate. Each electrode unit corresponds one-to-one with a protrusion in the pressure-sensitive conductive layer 2. The flexible substrate is made of polyethylene terephthalate (PET) or polyimide (PI), with a thickness of 100-200µm and dimensions of 30mm in length and 20mm in width. The electrode units are selected from silver paste / silver-based nano-conductive ink, copper-based nano-conductive ink, graphene ink, carbon nanotube ink, liquid metal ink, or poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) ink. In this embodiment, the flexible array electrode 5 consists of 12 independent electrode units distributed in an array of circular dots, independently led out by leads. Each electrode point corresponds one-to-one with a columnar protrusion in the pressure-sensitive conductive layer 2, enabling independent acquisition and transmission of multi-point tactile signals, ensuring high spatial resolution. Each electrode unit has a diameter of 3mm.

[0030] like Figure 5 The diagram shown is an integrated structural diagram of the biomimetic flexible tactile sensor array provided in an embodiment of the present invention. Each functional layer forms a flexible sensing unit array with high integration and compact structure.

[0031] like Figure 6The diagram shows an assembly cross-sectional view of the biomimetic flexible tactile sensor array provided in an embodiment of the present invention. The flexible common electrode and the flexible array electrode 5 are located at the upper and lower ends of the sensor, respectively, forming an electrode pair. In the middle are a pressure-sensitive conductive layer 2 and a biomimetic structural layer 3. The columnar protrusions of the pressure-sensitive conductive layer 2 and the octopus-like suction cup structure of the biomimetic structural layer 3 are precisely nested, with a preset initial gap d between them. When no external force is applied, the gap d completely isolates the pressure-sensitive conductive layer 2 from the flexible array electrode 5, and the sensor is in a zero-power standby state. Under external force, the gap d is easily compressed, making the pressure-sensitive conductive layer 2 and the flexible array electrode 5 conductive, thus achieving a sensitive response to the tactile signal. Furthermore, the performance and conductive trigger threshold of this tactile sensor can be flexibly adjusted by adjusting the edge tilt angle θ of the octopus-like suction cup structure and the gap d. The biomimetic octopus suction cup structure is easily compressed, can accurately sense pressure, and achieve pressure triggering. Moreover, its curvature, height, and other structural parameters can also be flexibly adjusted. Applying it in this invention enables triggering under different pressures, thereby achieving sensor customization.

[0032] The fabrication method of the above-mentioned biomimetic flexible tactile sensor array includes the following steps: S1, Fabrication of flexible single electrode 1 and flexible array electrode 5: Flexible single electrode 1 and flexible array electrode 5 are fabricated using ink direct writing or inkjet printing technology, completing the fabrication of patterned electrodes and leading out leads.

[0033] The specific process for preparing the flexible single electrode 1 and the flexible array electrode 5 is as follows: Select polyethylene terephthalate (PET) or polyimide (PI) with a thickness of 150µm, clean them, and print silver paste nano-conductive ink onto the polyethylene terephthalate in situ according to the electrode pattern using ink direct writing or inkjet printing technology to form the flexible single electrode 1 with a single electrode structure and the flexible array electrode 5 with an array distribution, respectively. After printing, place them in an 80℃ oven to cure for 30 minutes to make the silver paste nano-conductive ink firmly adhere to the PET surface. After the conductive ink is completely cured, cut them into the preset size, and finally fix the silver wires to the electrode ends with copper tape to complete the preparation.

[0034] S2, Preparation of pressure-sensitive conductive layer 2: A porous structure composed of conductive filler and elastomer polymer is prepared by using a 3D printing template molding process combined with the sacrificial salt template method to obtain a pressure-sensitive conductive layer 2 with multiple protrusions on the surface.

[0035] The specific process for preparing the pressure-sensitive conductive layer 2 is as follows: A mold with a columnar protrusion array is prepared using 3D printing technology. Carbon nanotubes (CNTs) are ultrasonically dispersed in an organic solvent (isopropanol or tetrahydrofuran) at a mass ratio of 1:(50~150). Then, polydimethylsiloxane (PDMS) precursor and salt (NaCl) particles are added and mixed evenly. The amount of NaCl added is 20% of the mass of the PDMS precursor. After the organic solvent evaporates, a curing agent is added and the mixture is stirred for another 10 minutes. Then, the mixed solution is poured into the mold, degassed under vacuum, and cured at 70°C. After peeling off the film, it is immersed in deionized water to dissolve and remove the NaCl particles in the polydimethylsiloxane (PDMS) / carbon nanotube (CNT) composite system, resulting in a pressure-sensitive conductive layer 2 with columnar protrusions on the surface.

[0036] S3, Preparation of biomimetic structural layer 3: Using 3D printing template molding process, an octopus-like suction cup structure is prepared using elastomer polymer as raw material to obtain biomimetic structural layer 3.

[0037] The specific process for preparing the biomimetic structural layer 3 is as follows: An array mold with an octopus-like sucker structure is prepared using 3D printing technology. Polydimethylsiloxane (PDMS) precursor and curing agent are mixed and stirred evenly at a ratio of 12.5:1 and then poured into the bottom of the mold to form the biomimetic structural part. After preliminary heating for 30 minutes for semi-curing, the PDMS precursor and curing agent are mixed and stirred evenly at a ratio of 7.5:1 and then poured onto the top of the biomimetic structure. After vacuum degassing, it is cured at 70℃. After demolding, the biomimetic structural layer 3 with an octopus-like sucker structure on its surface is obtained, and its overall structure exhibits a gradient modulus distribution.

[0038] S4, Prepare buffer layer 4: Cut the porous sponge structure into a hollow frame structure of a preset size to obtain buffer layer 4.

[0039] The specific process for preparing buffer layer 4 is as follows: clean the polyurethane sponge with dimensions of 30mm×20mm×1.5mm, cut it into a hollow frame structure with a rectangular cutout area of ​​25mm×15mm in the center area, and obtain buffer layer 4. Its thickness and frame size can be adjusted according to the sensor requirements.

[0040] S5, Overall Packaging: The flexible single electrode 1, pressure-sensitive conductive layer 2, biomimetic structure layer 3, buffer layer 4, and flexible array electrode 5 are aligned in order from top to bottom and then packaged as a whole to complete the fabrication of the biomimetic flexible tactile sensor array.

[0041] In the initial state, the pressure-sensitive conductive layer 2 is located inside the biomimetic structure, and an initial gap d is maintained between the columnar protrusions of the pressure-sensitive conductive layer 2 and the biomimetic structure of the biomimetic structure layer 3. The sensor is in a zero-power standby state. When the sensor is subjected to external pressure, the biomimetic structure and the buffer layer 4 are compressed and deformed, causing the columnar protrusions of the pressure-sensitive conductive layer 2 to make contact with the electrode units of the flexible array electrode 5, generating a regular resistance change. The pressure signal is sensed based on the change in resistance.

[0042] The above are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent structural or step transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A biomimetic flexible tactile sensor array, characterized in that, From top to bottom, they include: A flexible single electrode (1) includes a flexible substrate and a common electrode disposed on the surface of the flexible substrate; The pressure-sensitive conductive layer (2) is composed of an elastic matrix and conductive fillers dispersed in the elastic matrix. Multiple protrusions with the same structure are distributed in an array at intervals on the surface of the pressure-sensitive conductive layer (2). The biomimetic structure layer (3) has a biomimetic structure on its surface corresponding to the protrusion. The biomimetic structure has a through hole. The protrusion is embedded in the hole of the biomimetic structure. In the unstressed state, there is a preset gap between the end face of the protrusion and the end face of the biomimetic structure. The buffer layer (4) is a hollow frame structure with a thickness consistent with the height of the bionic structure. The bionic structure is inserted into the hollow part of the buffer layer (4) to achieve the interlocking and cooperation between the bionic structure layer (3) and the buffer layer (4). The flexible array electrode (5) includes a flexible substrate and multiple independent electrode units, each electrode unit corresponding to a protrusion of the pressure-sensitive conductive layer (2). Each biomimetic structure and buffer layer (4) undergoes compression deformation when subjected to force, causing the protrusions corresponding to the biomimetic structure to contact and conduct with the electrode unit, generating resistance changes and realizing pressure sensing. After the force is removed, each component returns to its original configuration.

2. The biomimetic flexible tactile sensor array according to claim 1, characterized in that, The biomimetic structure is modeled after an octopus sucker.

3. The biomimetic flexible tactile sensor array according to claim 1, characterized in that, The flexible substrate of the flexible single electrode (1) and the flexible matrix of the flexible array electrode (5) are made of PET or PI material. The shared electrode and electrode unit are selected from any one of silver paste / silver-based nano-conductive ink, copper-based nano-conductive ink, graphene ink, carbon nanotube ink, liquid metal ink or poly(3,4-ethylenedioxythiophene):polystyrene sulfonate ink.

4. The biomimetic flexible tactile sensor array according to claim 1, characterized in that, The pressure-sensitive conductive layer (2) has a porous structure and is composed of polydimethylsiloxane and carbon nanotubes.

5. The biomimetic flexible tactile sensor array according to claim 4, characterized in that, The ratio of polydimethylsiloxane precursor to curing agent in the polydimethylsiloxane is 10:

1.

6. The biomimetic flexible tactile sensor array according to claim 5, characterized in that, The pressure-sensitive conductive layer (2) is prepared by the sacrificial salt template method to form a porous structure, wherein the amount of NaCl added is 10% to 30% of the mass of the polydimethylsiloxane precursor.

7. The biomimetic flexible tactile sensor array according to claim 1, characterized in that, The biomimetic structure layer (3) includes a substrate structure, the biomimetic structure is integrated on the substrate structure, and the modulus of the biomimetic structure is lower than that of the substrate structure.

8. The biomimetic flexible tactile sensor array according to claim 7, characterized in that, The biomimetic structure layer (3) is made of polydimethylsiloxane. The ratio of polydimethylsiloxane precursor to curing agent in the biomimetic structure is 12.5:1, and the ratio of polydimethylsiloxane precursor to curing agent in the substrate structure is 7.5:

1.

9. The biomimetic flexible tactile sensor array according to claim 1, characterized in that, The buffer layer (4) has a porous sponge structure and is made of polyurethane or melamine.

10. A method for fabricating a biomimetic flexible tactile sensor array as described in any one of claims 1 to 9, characterized in that, Includes the following steps: S1, Fabrication of flexible single electrode (1) and flexible array electrode (5): Flexible single electrode (1) and flexible array electrode (5) are fabricated using ink direct writing or inkjet printing technology, and leads are drawn out; S2, Preparation of pressure-sensitive conductive layer (2): A porous structure composed of conductive filler and elastomer polymer was prepared by using 3D printing template molding process combined with sacrificial salt template method to obtain a pressure-sensitive conductive layer (2) with multiple protrusions on the surface. S3, Preparation of biomimetic structural layer (3): Using 3D printing template molding process, an octopus sucker structure is prepared using elastomer polymer as raw material to obtain biomimetic structural layer (3). S4, Prepare buffer layer (4): Cut the porous sponge structure into a hollow frame structure of a preset size to obtain buffer layer (4). S5, Overall Packaging: The above-mentioned flexible single electrode (1), pressure-sensitive conductive layer (2), biomimetic structure layer (3), buffer layer (4), and flexible array electrode (5) are aligned in order from top to bottom and then packaged as a whole to complete the fabrication of the biomimetic flexible tactile sensor array.

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