Tactile sensor

Abstract

This invention relates to the field of sensor technology and provides a tactile sensor. The tactile sensor includes a base layer, a first flexible circuit board layer, a second flexible circuit board layer, a first piezoresistive film layer, and a second piezoresistive film layer. The base layer has at least one first cantilever beam structure. The first flexible circuit board layer has at least one second cantilever beam structure corresponding to each of the at least one first cantilever beam structure and a first electrode formed on each second cantilever beam structure. The second flexible circuit board layer has at least one third cantilever beam structure corresponding to each of the at least one first cantilever beam structure and a second electrode formed on each third cantilever beam structure. At least one first piezoresistive film layer corresponds to at least one second cantilever beam structure, and at least one second piezoresistive film layer corresponds to at least one third cantilever beam structure. The tactile sensor of this invention can sense the magnitude and dynamic distribution of contact interaction forces, resulting in a good user experience.

Description

Technical Field

[0001] This invention relates to the field of sensor technology, and more particularly to a tactile sensor. Background Technology

[0002] With the rapid development of artificial intelligence and humanoid robots, robots are playing an increasingly important role in human life. A key indicator for evaluating the level of intelligence a robot can contribute to human life is its operational capabilities. Tactile sensors, as the medium for robots to interact with the outside world, enable robots to achieve self-perception and feedback, better performing tasks such as object recognition, operational status assessment, and collision detection. In various daily tasks, sensors are required not only to sense contact forces and their dynamic distribution, but also to possess a certain degree of flexibility and extensibility, providing a skin-like cushioning and protective function.

[0003] In related technologies, tactile sensors generally include resistive tactile sensors and piezoelectric tactile sensors. Resistive tactile sensors use flexible conductive composite materials (such as carbon nanotube / silicone composites, conductive rubber) as the sensitive layer, converting force signals through changes in the conductive pathway caused by contact pressure. These sensors are simple in structure, low in cost, and possess a certain degree of flexibility, but their dynamic response speed is slow, making it difficult to accurately capture the dynamic distribution characteristics of the applied force. Furthermore, their limited extensibility leads to performance degradation during complex deformation movements of robots. Piezoelectric tactile sensors, on the other hand, utilize the piezoelectric effect of piezoelectric materials to sense dynamic forces and can detect instantaneous force changes. However, their material flexibility is poor, their buffering performance is insufficient, and they struggle to achieve large-area uniform force distribution detection. Therefore, existing tactile sensors suffer from poor sensing performance and inadequate buffering capabilities.

[0004] Therefore, it is necessary to provide a new tactile sensor to solve the above problems. Summary of the Invention

[0005] The purpose of this invention is to provide a tactile sensor that achieves the flexibility and extensibility of biomimetic skin tissue while sensing the magnitude and dynamic distribution of contact interaction forces, resulting in a good user experience.

[0006] This invention provides a tactile sensor, the tactile sensor comprising:

[0007] The base layer has at least one first cantilever beam structure, which deforms along the thickness direction of the base layer;

[0008] A first flexible circuit board layer and a second flexible circuit board layer are respectively fixed on opposite sides in the thickness direction of the base layer. The first flexible circuit board layer has at least one second cantilever beam structure corresponding to the at least one first cantilever beam structure and a first electrode formed on each second cantilever beam structure. The second flexible circuit board layer has at least one third cantilever beam structure corresponding to the at least one first cantilever beam structure and a second electrode formed on each third cantilever beam structure.

[0009] At least one first piezoresistive film layer, wherein the at least one first piezoresistive film layer corresponds one-to-one with the at least one second cantilever beam structure, and is respectively fixed to the side of the corresponding second cantilever beam structure away from the base layer;

[0010] At least one second piezoresistive film layer, the at least one second piezoresistive film layer corresponding one-to-one with the at least one third cantilever beam structure, and respectively fixed to the side of the corresponding third cantilever beam structure away from the base layer.

[0011] Preferably, the tactile sensor further includes an upper surface layer, the upper surface layer having at least one sensor contact unit portion corresponding to each of the at least one second piezoresistive film layer, the at least one sensor contact unit portion being fixed to the side of their respective corresponding second piezoresistive film layer away from the base layer.

[0012] Preferably, the upper surface layer further includes a connecting portion that connects at least two of the sensor contact unit portions, the connecting portion being fixed to the side of the second flexible circuit board layer away from the base layer.

[0013] Preferably, the tactile sensor further includes a support layer, which is fixed to the side of the first flexible circuit board layer away from the base layer, and has a clearance through hole to avoid the at least one second cantilever beam structure; the clearance through hole is disposed opposite to the second cantilever beam structure so as to provide movement space for the second cantilever beam structure when the second cantilever beam structure deforms.

[0014] Preferably, each of the first piezoresistive film layers includes a first piezoresistive sensitive layer fixed to the side of the corresponding second cantilever beam structure away from the base layer and a first protective layer fixed to the side of the first piezoresistive sensitive layer away from the base layer; each of the second piezoresistive film layers includes a second piezoresistive sensitive layer fixed to the side of the corresponding third cantilever beam structure away from the base layer and a second protective layer fixed to the side of the second piezoresistive sensitive layer away from the base layer.

[0015] Preferably, both the first electrode and the second electrode are interdigitated electrodes.

[0016] Preferably, each of the first cantilever beam structures has the same shape as the corresponding second cantilever beam structure and the third cantilever beam structure.

[0017] Preferably, the surface of each first piezoresistive film layer away from the substrate is flush with the surface of the first flexible circuit board layer away from the substrate, and the surface of each second piezoresistive film layer away from the substrate is flush with the surface of the second flexible circuit board layer away from the substrate.

[0018] Preferably, the at least one first cantilever beam structure is provided in multiple ways, and the multiple first cantilever beam structures are arranged in an array of M rows × N columns, where M and N are both positive integers.

[0019] Preferably, the at least one first cantilever beam structure is provided in multiple ways, and the multiple first cantilever beam structures are arranged along the contour line of the tactile sensing object.

[0020] Preferably, when the sensor contact unit is subjected to an external contact force, it deforms, causing changes in the strain of the third cantilever beam structure, the first cantilever beam structure, and the second cantilever beam structure. The strains generated by the first piezoresistive film layer and the second piezoresistive film layer are equal in magnitude and opposite in direction. The voltage changes of the first piezoresistive film layer and the second piezoresistive film layer are detected by a Wheatstone half-bridge circuit.

[0021] By definition, the resistance of a single first piezoresistive film layer and a single second piezoresistive film layer are both R m, the reference resistor is Rf, and the power supply voltage is V cc, the voltage change detected by the Wheatstone half-bridge circuit is V m;

[0022] The relationship between the voltage changes detected by the Wheatstone half-bridge circuit is as follows:

[0023] ;

[0024] in, The value of the resistance change caused by the deformation of the first or second piezoresistive film layer due to external contact force, where k is the sensitivity coefficient. The strain is the piezoresistive membrane strain.

[0025] Preferably, the base layer is made of PEEK, PI, or PET material;

[0026] The thickness of the base layer is 0.01mm to 5mm.

[0027] Preferably, the support layer is made of PEEK, PI or PET material; the thickness of the support layer is 0.02mm to 2mm.

[0028] Preferably, both the first protective layer and the second protective layer are made of silicone or PI material.

[0029] Preferably, the upper surface layer is made of silicone or PDMS material.

[0030] Compared with related technologies, the tactile sensor of this invention is constructed by sequentially stacking and fixing a first flexible circuit board layer, a base layer, and a second flexible circuit board layer. The base layer has at least one first cantilever beam structure. The first flexible circuit board layer has at least one second cantilever beam structure corresponding to each of the at least one first cantilever beam structure and a first electrode formed on each of the second cantilever beam structures. The second flexible circuit board layer has at least one third cantilever beam structure corresponding to each of the at least one first cantilever beam structure and a second electrode formed on each of the third cantilever beam structures. At least one first piezoresistive film layer and... The at least one second cantilever beam structure corresponds one-to-one with the at least one third cantilever beam structure. The second piezoresistive film layer interacts with the outside world and is subjected to contact force, causing the second flexible circuit board layer to deform. This causes changes in the strain of the second piezoresistive film layer and the first piezoresistive film layer on the upper and lower surfaces of the first cantilever beam structure. Moreover, the strains of the second piezoresistive film layer and the first piezoresistive film layer are equal in magnitude and opposite in direction. In this way, while achieving the flexibility and extensibility of biomimetic skin tissue, it is also possible to sense the magnitude and dynamic distribution of contact interaction force, resulting in a good user experience. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein:

[0032] Figure 1 A three-dimensional structural diagram of the tactile sensor provided in an embodiment of the present invention;

[0033] Figure 2 This is an exploded view of the structure of the tactile sensor provided in an embodiment of the present invention;

[0034] Figure 3 for Figure 1 Sectional view along line AA;

[0035] Figure 4 for Figure 3 A magnified view of part B;

[0036] Figure 5A schematic diagram illustrating the application of the palm contour on the upper surface of the tactile sensor provided in an embodiment of the present invention;

[0037] Figure 6 This is a schematic diagram of the circuit detection application of the tactile sensor provided in an embodiment of the present invention.

[0038] Among them, 100 is a tactile sensor, 1 is a support layer, 11 is a clearance through hole, 2 is a first flexible circuit board layer, 21 is a second cantilever beam structure, 22 is a first electrode, 3 is a base layer, 31 is a first cantilever beam structure, 4 is a second flexible circuit board layer, 41 is a third cantilever beam structure, 42 is a second electrode, 5 is an upper surface layer, 51 is a connecting part, 52 is a sensor contact unit part, 6 is a first piezoresistive film layer, 61 is a first piezoresistive sensitive layer, 62 is a first protective layer, 7 is a second piezoresistive film layer, 71 is a second piezoresistive sensitive layer, and 72 is a second protective layer. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] Please see the appendix Figures 1-6 As shown, this embodiment of the invention provides a tactile sensor 100, which includes a base layer 3. The base layer 3 has at least one first cantilever beam structure 31, which deforms along the thickness direction of the base layer 3. By providing a plurality of first cantilever beam structures 31 distributed on the base layer 3, and through structural design of the thickness of the base layer 3 and the length and width of the first cantilever beam structures 31, different ranges and resolution requirements of the tactile sensor 100 can be achieved. In addition, the distribution characteristics of the first cantilever beam structures 31 can be designed according to the sensor's external dimensions.

[0041] A first flexible circuit board layer 2 and a second flexible circuit board layer 4 are fixed to opposite sides of the base layer 3 in the thickness direction. The first flexible circuit board layer 2 has at least one second cantilever beam structure 21 corresponding to at least one first cantilever beam structure 31 and a first electrode 22 formed on each second cantilever beam structure 21. The second flexible circuit board layer 4 has at least one third cantilever beam structure 41 corresponding to at least one first cantilever beam structure 31 and a second electrode 42 formed on each third cantilever beam structure 41. The first flexible circuit board layer 2 is disposed on the lower surface of the base layer 3, and the second flexible circuit board layer 4 is disposed on the upper surface of the base layer 3, with the first flexible circuit board layer 2 and the second flexible circuit board layer 4 positioned opposite each other. Specifically, by embedding the first electrode 22 into the first flexible circuit board layer 2, and making the surface of the first electrode 22 flush with the surface of the first flexible circuit board layer 2, installation space is saved. By embedding the second electrode 42 into the second flexible circuit board layer 4, and making the surface of the second electrode 42 flush with the surface of the second flexible circuit board layer 4, installation space is saved.

[0042] At least one first piezoresistive film layer 6 is provided, and each of the at least one first piezoresistive film layer 6 corresponds one-to-one with the at least one second cantilever beam structure 21, and is respectively fixed to the side of the corresponding second cantilever beam structure 21 away from the base layer 3. The first piezoresistive film layer 6 is used to detect the change in resistance of the piezoresistive material when deformation occurs under external pressure.

[0043] At least one second piezoresistive film layer 7 is provided, each corresponding to one of the at least one third cantilever beam structure 41, and each is fixed to the side of its corresponding third cantilever beam structure 41 away from the base layer 3. The second piezoresistive film layer 7 is used to detect changes in the resistance of the piezoresistive material when deformation occurs under external pressure. Thus, the pressure on the upper and lower sides can be detected using the first piezoresistive film layer 6 and the second piezoresistive film layer 7. Through interaction with the external environment, the second piezoresistive film layer 7 is subjected to contact force, causing deformation of the second flexible circuit board layer 4. This results in changes in the strain of the second piezoresistive film layer 7 and the first piezoresistive film layer 6 on the upper and lower surfaces of the first cantilever beam structure 31. The strains of the second piezoresistive film layer 7 and the first piezoresistive film layer 6 are equal in magnitude and opposite in direction. This allows for the perception of the magnitude and dynamic distribution of contact interaction forces while achieving the flexibility and extensibility of biomimetic skin tissue, resulting in a good user experience.

[0044] In this embodiment, the tactile sensor 100 further includes an upper surface layer 5. The upper surface layer 5 has at least one sensor contact unit 52 corresponding to each of the at least one second piezoresistive film layer 7. The at least one sensor contact unit 52 is fixed to the side of its corresponding second piezoresistive film layer 7 away from the base layer 3. When the upper surface layer 5 interacts with the outside world and is subjected to contact force, it deforms, causing changes in the strain of the second piezoresistive film layer 7 and the first piezoresistive film layer 6 on the upper and lower surfaces of the first cantilever beam structure 31. The strains of the second piezoresistive film layer 7 and the first piezoresistive film layer 6 are equal in magnitude and opposite in direction. This allows for the perception of the magnitude and dynamic distribution of contact interaction forces while achieving the flexibility and extensibility of biomimetic skin tissue, resulting in a good user experience.

[0045] Among them, the shape of the upper surface layer 5 can be arranged according to the outline of the corresponding structure. For example, for the electronic skin of the palm, it can be arranged according to the shape of the palm.

[0046] In this embodiment, the upper surface layer 5 and the sensor contact unit 52 can be integrally molded, which simplifies the structure and reduces the difficulty of mounting. Of course, they can also be separated into three parts, which has a wider range of applications.

[0047] In this embodiment, the upper surface layer 5 further includes a connecting portion 51 that connects at least two of the sensor contact unit portions 52. The connecting portion 51 is fixed to the side of the second flexible circuit board layer 4 away from the base layer 3. The upper surface layer 5 is used to directly contact external objects, and when a contact force occurs, it will push the cantilever beam to deform.

[0048] In this embodiment, the tactile sensor 100 further includes a support layer 1. The support layer 1 is fixed to the side of the first flexible circuit board layer 2 away from the base layer 3 and has a clearance through hole 11 to avoid the at least one second cantilever beam structure 21. The clearance through hole 11 is disposed opposite to the second cantilever beam structure 21 so as to provide movement space for the second cantilever beam structure 21 when it deforms. By using the support layer 1 to support the first flexible circuit board layer 2, and leaving a clearance through hole 11 at the corresponding position of the first piezoresistive film layer 6, movement space can be provided for the deformation of the second cantilever beam structure 21 at the first piezoresistive film layer 6.

[0049] In this embodiment, each of the first piezoresistive film layers 6 includes a first piezoresistive sensitive layer 61 fixed to the side of the corresponding second cantilever beam structure 21 away from the base layer 3 and a first protective layer 62 fixed to the side of the first piezoresistive sensitive layer 61 away from the base layer 3; each of the second piezoresistive film layers 7 includes a second piezoresistive sensitive layer 71 fixed to the side of the corresponding third cantilever beam structure 41 away from the base layer 3 and a second protective layer 72 fixed to the side of the second piezoresistive sensitive layer 71 away from the base layer 3. Specifically, the first protective layer 62 is used to protect the first piezoresistive sensitive layer 61, serving to provide insulation and enhance reliability. The resistance of the piezoresistive material changes when the first piezoresistive sensitive layer 61 deforms due to external pressure, improving detection accuracy. The second protective layer 72 is used to protect the second piezoresistive sensitive layer 71, serving to provide insulation and enhance reliability. The resistance of the piezoresistive material changes when the second piezoresistive sensitive layer 71 deforms due to external pressure, improving detection accuracy. The first piezoresistive film layers 6 and the second piezoresistive film layers 7 are arranged in a 3×3 array.

[0050] In this embodiment, both the first electrode 22 and the second electrode 42 are interdigitated electrodes. Both the first electrode 22 and the second electrode 42 are arranged in a 3×3 array.

[0051] In this embodiment, each of the first cantilever beam structures 31 has the same shape as the corresponding second cantilever beam structure 21 and the third cantilever beam structure 41, such as rectangular, circular, or palm-shaped.

[0052] In this embodiment, the first cantilever beam structure 31 is a rectangular or contoured structure. The contour can be a circular contour, a palm contour, etc.

[0053] In this embodiment, the surface of each first piezoresistive film layer 6 away from the base layer 3 is flush with the surface of the first flexible circuit board layer 2 away from the base layer 3, and the surface of each second piezoresistive film layer 7 away from the base layer 3 is flush with the surface of the second flexible circuit board layer 4 away from the base layer 3. This saves installation space.

[0054] In this embodiment, the at least one first cantilever beam structure 31 is provided in multiple ways, and the multiple first cantilever beam structures 31 are arranged in an array of M rows × N columns, where M and N are both positive integers.

[0055] In this embodiment, multiple first cantilever beam structures 31 are arranged in a 3×3 array. By arranging the first cantilever beam structures 31 in a 3×3 array on the base layer 3, the stress-bearing range of the first cantilever beam structures 31 is increased, making them adaptable to various applications, such as rectangular or circular shapes. Of course, the first cantilever beam structures 31 can also be arranged in other ways, which will not be described here.

[0056] In this embodiment, the at least one first cantilever beam structure 31 is provided in multiple ways, and the multiple first cantilever beam structures 31 are arranged along the contour line of the tactile sensing object. For example... Figure 5 As shown, for example, if the tactile sensing object is the palm, then the sensor is arranged along the outline of the palm.

[0057] In this embodiment, when the sensor contact unit 52 is subjected to an external contact force, it deforms, causing changes in the strain of the third cantilever beam structure 41, the first cantilever beam structure 31, and the second cantilever beam structure 21. Consequently, the strains generated by the first piezoresistive film layer 6 and the second piezoresistive film layer 7 are equal in magnitude and opposite in direction. The voltage changes of the first piezoresistive film layer 6 and the second piezoresistive film layer 7 are detected by a Wheatstone half-bridge circuit. Both the second piezoresistive film layer 7 and the first piezoresistive film layer 6 are directly opposite the first cantilever beam structure 31. When the second piezoresistive film layer 7 is subjected to pressure, it presses the base layer 3 towards the side closer to the base layer 3, causing the base layer 3 to deform the first piezoresistive film layer 6 away from the base layer 3. Since the second piezoresistive film layer 7, the first cantilever beam structure 31, and the first piezoresistive film layer 6 are in contact, they experience the same stress. Preferably, the compressive force exerted on the second piezoresistive film layer 7 and the first piezoresistive film layer 6 towards the side closer to the base layer 3 is a positive strain force, and the compressive force output by the base layer 3 to the second piezoresistive film layer 7 and the first piezoresistive film layer 6 is a negative strain force; therefore, the strains generated by the first piezoresistive film layer 6 and the second piezoresistive film layer 7 are in opposite directions.

[0058] By definition, the resistance of a single first piezoresistive film layer 6 and a single second piezoresistive film layer 7 is both R m, the reference resistor is Rf, and the power supply voltage is V cc, the voltage change detected by the Wheatstone half-bridge circuit is V m;

[0059] The R m includes a first resistor and a second resistor, and Rf includes a first reference resistor and a second reference resistor; the first end of the first resistor is connected to the first end of the first reference resistor and connected to the power supply voltage, the second end of the first resistor is connected to the first end of the second resistor, the second end of the first reference resistor is connected to the first end of the second reference resistor, and the second end of the second resistor is connected to the second end of the second reference resistor and grounded.

[0060] in, ;

[0061] ;

[0062] in, Rm=Rf, ;

[0063] The relationship between the voltage changes detected by the Wheatstone half-bridge circuit is as follows:

[0064] ;

[0065] in, The resistance change caused by the deformation of the first piezoresistive film layer 6 or the second piezoresistive film layer 7 due to external contact force is denoted by k, which is the sensitivity coefficient, and the strain of the piezoresistive film is denoted by . The detection voltage obtained through the Wheatstone half-bridge circuit and the corresponding cantilever beam number information can be used to calculate the magnitude and dynamic distribution information of the contact interaction force through a decoupling algorithm. When the upper surface layer 5 interacts with the outside world and is subjected to contact force, the upper surface layer 5 deforms, causing the strain of the second piezoresistive film layer 7 and the first piezoresistive film layer 6 on the upper and lower surfaces of the first cantilever beam structure 31 to change. The strains of the second piezoresistive film layer 7 and the first piezoresistive film layer 6 are equal in magnitude and opposite in direction. This allows for the perception of the magnitude and dynamic distribution information of the contact interaction force while achieving the flexibility and extensibility of biomimetic skin tissue, resulting in a good user experience.

[0066] In this embodiment, the base layer 3 is made of PEEK (polyetheretherketone), PI (polyimide), or PET (polyethylene terephthalate). This results in good insulation and deformation properties for the base layer 3. PEEK is a high-performance special engineering plastic, a linear aromatic polymer, possessing properties such as high temperature resistance, high mechanical strength, chemical corrosion resistance, low water absorption, and biocompatibility. PI is primarily aromatic polyimide, with an imide ring in its molecular structure, exhibiting extremely strong high temperature resistance, weather resistance, flexibility, insulation, and excellent mechanical strength. PET is a general-purpose engineering plastic, a semi-crystalline polymer, possessing good flexibility, transparency, processability, moderate mechanical strength, and low cost.

[0067] In this embodiment, the thickness of the base layer 3 is 0.01mm to 5mm. Preferably, the thickness of the base layer 3 is 1mm, which is thin and saves costs.

[0068] In this embodiment, the support layer 1 is made of PEEK, PI, or PET material.

[0069] In this embodiment, the thickness of the support layer 1 is 0.02mm to 2mm. Depending on the different ranges and resolution requirements of the tactile sensor 100, the thickness of the support layer 1 can be 0.02mm to 2mm, providing good support performance and saving costs. Preferably, the thickness of the support layer 1 is 1mm.

[0070] In this embodiment, both the first protective layer 62 and the second protective layer 72 are made of silicone or PI material. They provide insulation, enhance reliability, and improve protective performance.

[0071] In this embodiment, the upper surface layer 5 is made of silicone or PDMS (polydimethylsiloxane). Silicone material offers flexible adaptation and deformation following, providing good cushioning. PDMS material exhibits good processability and structural controllability, high transparency, and high performance stability.

[0072] Specifically, the upper surface layer 5 consists of three sets of sensor contact unit sections 52, the positions of which correspond to the positions of the third cantilever beam structure 41. The upper surface layer 5 is in direct contact with external objects, and when a contact force occurs, it will cause the sensor contact unit sections 52 to deform.

[0073] Compared with related technologies, the tactile sensor of this invention is constructed by sequentially stacking and fixing a first flexible circuit board layer, a base layer, and a second flexible circuit board layer. The base layer has at least one first cantilever beam structure. The first flexible circuit board layer has at least one second cantilever beam structure corresponding to each of the at least one first cantilever beam structure and a first electrode formed on each of the second cantilever beam structures. The second flexible circuit board layer has at least one third cantilever beam structure corresponding to each of the at least one first cantilever beam structure and a second electrode formed on each of the third cantilever beam structures. At least one first piezoresistive film layer and... The at least one second cantilever beam structure corresponds one-to-one with the at least one third cantilever beam structure. The second piezoresistive film layer interacts with the outside world and is subjected to contact force, causing the second flexible circuit board layer to deform. This causes changes in the strain of the second piezoresistive film layer and the first piezoresistive film layer on the upper and lower surfaces of the first cantilever beam structure. Moreover, the strains of the second piezoresistive film layer and the first piezoresistive film layer are equal in magnitude and opposite in direction. In this way, while achieving the flexibility and extensibility of biomimetic skin tissue, it is also possible to sense the magnitude and dynamic distribution of contact interaction force, resulting in a good user experience.

[0074] The above are merely embodiments of the present invention. It should be noted that those skilled in the art can make improvements without departing from the inventive concept of the present invention, but these improvements all fall within the protection scope of the present invention.

Claims

1. A tactile sensor, characterized in that, The tactile sensor includes: The base layer has at least one first cantilever beam structure, which deforms along the thickness direction of the base layer; A first flexible circuit board layer and a second flexible circuit board layer are respectively fixed on opposite sides in the thickness direction of the base layer. The first flexible circuit board layer has at least one second cantilever beam structure corresponding to the at least one first cantilever beam structure and a first electrode formed on each second cantilever beam structure. The second flexible circuit board layer has at least one third cantilever beam structure corresponding to the at least one first cantilever beam structure and a second electrode formed on each third cantilever beam structure. At least one first piezoresistive film layer, wherein the at least one first piezoresistive film layer corresponds one-to-one with the at least one second cantilever beam structure, and is respectively fixed to the side of the corresponding second cantilever beam structure away from the base layer; At least one second piezoresistive film layer, the at least one second piezoresistive film layer corresponding one-to-one with the at least one third cantilever beam structure, and respectively fixed to the side of the corresponding third cantilever beam structure away from the base layer; The tactile sensor further includes an upper surface layer, which has at least one sensor contact unit portion corresponding to the at least one second piezoresistive film layer. The at least one sensor contact unit portion is fixed to the side of its respective second piezoresistive film layer away from the base layer. When the sensor contact unit is subjected to an external contact force, it deforms, causing changes in the strain of the third cantilever beam structure, the first cantilever beam structure, and the second cantilever beam structure. The strains generated by the first piezoresistive film layer and the second piezoresistive film layer are equal in magnitude and opposite in direction. The voltage changes of the first piezoresistive film layer and the second piezoresistive film layer are detected by a Wheatstone half-bridge circuit.

2. The tactile sensor as described in claim 1, characterized in that, The upper surface layer also includes a connecting portion that connects at least two of the sensor contact unit portions, the connecting portion being fixed to the side of the second flexible circuit board layer away from the base layer.

3. The tactile sensor as described in claim 1, characterized in that, The tactile sensor further includes a support layer, which is fixed to the side of the first flexible circuit board layer away from the base layer, and has a clearance through hole to avoid the at least one second cantilever beam structure; the clearance through hole is disposed opposite to the second cantilever beam structure so as to provide movement space for the second cantilever beam structure when the second cantilever beam structure deforms.

4. The tactile sensor as described in claim 1, characterized in that, Each of the first piezoresistive membrane layers includes a first piezoresistive sensitive layer fixed to the side of the corresponding second cantilever beam structure away from the base layer and a first protective layer fixed to the side of the first piezoresistive sensitive layer away from the base layer; each of the second piezoresistive membrane layers includes a second piezoresistive sensitive layer fixed to the side of the corresponding third cantilever beam structure away from the base layer and a second protective layer fixed to the side of the second piezoresistive sensitive layer away from the base layer.

5. The tactile sensor as described in claim 1, characterized in that, Both the first electrode and the second electrode are interdigitated electrodes.

6. The tactile sensor as described in claim 1, characterized in that, Each of the first cantilever beam structures has the same shape as the corresponding second cantilever beam structure and the third cantilever beam structure.

7. The tactile sensor as claimed in claim 1, characterized in that, The surface of each first piezoresistive film layer on the side away from the substrate is flush with the surface of the first flexible circuit board layer on the side away from the substrate, and the surface of each second piezoresistive film layer on the side away from the substrate is flush with the surface of the second flexible circuit board layer on the side away from the substrate.

8. The tactile sensor as claimed in claim 1, characterized in that, The at least one first cantilever beam structure is provided in multiple ways, and the multiple first cantilever beam structures are arranged in an array of M rows × N columns, where M and N are both positive integers.

9. The tactile sensor as claimed in claim 1, characterized in that, The at least one first cantilever beam structure is provided in multiple ways, and the multiple first cantilever beam structures are arranged along the contour line of the tactile sensing object.

10. The tactile sensor as claimed in claim 1, characterized in that, By definition, the resistance of a single first piezoresistive film layer and a single second piezoresistive film layer are both R m, the reference resistor is Rf, and the power supply voltage is V cc, the voltage change detected by the Wheatstone half-bridge circuit is V m; The relationship between the voltage changes detected by the Wheatstone half-bridge circuit is as follows: ； in, The value of the resistance change caused by the deformation of the first or second piezoresistive film layer due to external contact force, where k is the sensitivity coefficient. The strain is the piezoresistive membrane strain.

11. The tactile sensor as claimed in claim 1, characterized in that, The base layer is made of PEEK, PI, or PET material; The thickness of the base layer is 0.01mm to 5mm.

12. The tactile sensor as claimed in claim 3, characterized in that, The support layer is made of PEEK, PI or PET material; the thickness of the support layer is 0.02mm to 2mm.

13. The tactile sensor as claimed in claim 4, characterized in that, Both the first protective layer and the second protective layer are made of silicone or PI material.

14. The tactile sensor as claimed in claim 1, characterized in that, The upper surface layer is made of silicone or PDMS material.

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