Probe structure flexible tactile sensor and preparation method thereof

Abstract

The present application belongs to the technical field of flexible electronics and sensors, and discloses a probe structure flexible tactile sensor and a preparation method thereof. The sensor comprises a flexible sensing probe and a flexible substrate layer. The flexible sensing probe is a two-segment bending flexible probe structure. The bottom surface of the flexible sensing probe is adhered to the surface of the flexible substrate layer. The top of the flexible sensing probe is provided with a magnetic strip. The flexible substrate layer comprises a planar electrode and a flexible substrate. The planar electrode outputs the electrical signal of the flexible sensing probe to an external circuit. The sensor of the present application converts the approach of a touched, vibrated or magnetically conductive object into the deformation of the flexible sensing probe through the flexible probe structure and the magnetic strip, and outputs an electrical signal. The sensor of the present application can work in both contact and non-contact modes, has the characteristics of multifunction, low cost, easy preparation and wearability, and can meet the actual needs of tactile recognition and non-contact sensing.

Description

Technical Field

[0001] This invention belongs to the field of flexible electronics and sensor technology, and particularly relates to a probe-structured flexible tactile sensor and its fabrication method. Background Technology

[0002] Tactile sensors can provide tactile information such as stress, strain, and vibration for robots, prosthetics, and human-computer interaction devices. In recent years, the continuous development of intelligent robot technology and artificial intelligence technology has placed higher demands on the performance and functionality of tactile sensors. For example, as the end effector of a robotic system, a robotic arm needs to perform intelligent tasks such as touch detection, surface recognition, and material recognition when moving in unstructured environments or grasping unknown objects. However, conventional visual sensors are limited by factors such as lighting and occlusion, and they struggle to effectively identify material and surface properties such as hardness, texture, and surface roughness. Therefore, advanced tactile sensors with tactile recognition capabilities are of great significance for the intelligent and autonomous perception of robotic systems. On the other hand, large-scale epidemics have created a significant demand for non-contact sensing and non-contact interaction. Sensors with non-contact operating modes help reduce surface contamination and decrease the chance of transmission of pathogens such as viruses. Therefore, developing non-contact sensing functions for tactile sensors has potential applications in wearable devices and other fields.

[0003] Currently, flexible tactile sensors, represented by electronic skin, have made significant progress in functional materials and basic performance. However, existing flexible tactile sensors mainly rely on planar structures such as multilayer flexible structures or biomimetic microstructures, and most adopt a direct contact operating mode. Traditional sensor structures and operating methods make it difficult to expand the tactile recognition and non-contact sensing functions of flexible tactile sensors, limiting their application in intelligent robots, human-computer interaction, and health monitoring. Summary of the Invention

[0004] The purpose of this invention is to provide a probe-structured flexible tactile sensor and its fabrication method to solve the above-mentioned technical problems.

[0005] To solve the above-mentioned technical problems, the specific technical solution of the probe structure flexible tactile sensor and its preparation method of the present invention is as follows:

[0006] A flexible tactile sensor with a probe structure includes a flexible sensing probe and a flexible substrate layer. The flexible sensing probe is a two-section bent flexible probe structure, including a bottom portion and an inclined portion. The connection between the bottom portion and the inclined portion forms a bending angle. The bottom portion of the flexible sensing probe is bonded and fixed to the surface of the flexible substrate layer. The inclined portion of the flexible sensing probe is divided into a free end that can be bent and deformed. The flexible sensing probe converts the contact of an object into the deformation of the flexible sensing probe. The top of the inclined portion of the flexible sensing probe has a magnetic strip. The magnetic strip converts the approach of a magnetically conductive object into the deformation of the flexible sensing probe. The flexible substrate layer is used to convert the deformation information of the flexible sensing probe into an electrical signal and transmit it to an external circuit.

[0007] Furthermore, the probe structure flexible tactile sensor includes a fixing block, which is fixed to the surface of the flexible substrate layer and bonded to the bottom of the inclined portion of the flexible sensing probe, so that the bending angle of the flexible sensing probe is a fixed value when there is no external stimulation.

[0008] Furthermore, the flexible substrate layer includes a planar electrode and a flexible substrate. The planar electrode is disposed on the surface of the flexible substrate. The main body of the flexible sensing probe is a piezoelectric sensing layer that is flexible and has piezoelectric sensing function. The magnetic strip is disposed on one or both sides of the top of the piezoelectric sensing layer. The piezoelectric sensing layer includes a flexible piezoelectric film, an upper encapsulation layer, and a lower encapsulation layer. The flexible piezoelectric film is located between the upper encapsulation layer and the lower encapsulation layer. The flexible piezoelectric film has a double-sided electrode, which is connected to the planar electrode of the flexible substrate layer.

[0009] Furthermore, the bottom area of ​​the flexible sensing probe is equal to or greater than 20 mm². 2 .

[0010] Furthermore, the main body of the fixing block has a triangular cross-sectional shape, and protrusions are provided on both sides of the fixing block. The protrusions protrude from both sides of the flexible sensing probe, restricting the tangential movement of the flexible sensing probe.

[0011] Furthermore, the flexible piezoelectric film is a polymer piezoelectric film with double-sided metallized electrodes, the upper and lower encapsulation layers are single-sided adhesive polymer encapsulation films, the magnetic strip is a polymer elastomer containing magnetic microparticles, the fixing block is made of resin suitable for 3D printing, and the planar electrode is made of a material that can be formulated into conductive ink.

[0012] Furthermore, the flexible sensing probe is one or more, the number of planar electrodes in the flexible substrate is the same as the number of flexible sensing probes, and each pair of planar electrodes in the flexible substrate is connected to each pair of double-sided electrodes in the flexible sensing probe.

[0013] Furthermore, the number of flexible sensing probes is equal to or greater than three, forming a flexible sensing probe array.

[0014] Furthermore, double-sided conductive tape is used to connect the planar electrode of the flexible substrate to the double-sided electrode of the flexible piezoelectric film.

[0015] This invention also discloses a method for fabricating a probe-structured flexible tactile sensor, comprising the following steps:

[0016] Step 1: Fabrication of the piezoelectric sensing layer: Cut the flexible piezoelectric film, the upper encapsulation layer, and the lower encapsulation layer, stack the upper encapsulation layer, the flexible piezoelectric film, and the lower encapsulation layer in sequence, and encapsulate them to obtain the piezoelectric sensing layer.

[0017] Step 2: Fabrication of the flexible sensing probe: The piezoelectric sensing layer is mechanically bent to form a two-section bent flexible probe structure. A magnetic strip is glued to the top of the piezoelectric sensing layer and a fixing block is glued to the bottom of the piezoelectric sensing layer to obtain the flexible sensing probe.

[0018] Step 3: Fabrication of the flexible substrate: A planar electrode array is fabricated on the surface of the flexible substrate to obtain the flexible substrate;

[0019] Step 4: Bonding the probe array: Bond the bottom surface of the flexible sensing probe to the surface of the flexible substrate layer, and connect a pair of double-sided electrodes of the flexible piezoelectric film to a pair of planar electrodes of the flexible substrate layer to obtain a probe-structured flexible tactile sensor.

[0020] The probe-structured flexible tactile sensor and its fabrication method of the present invention have the following advantages:

[0021] (1) The flexible tactile sensor with probe structure provided by the present invention has a flexible probe structure based on a flexible piezoelectric thin film. This design enables the sensor of the present invention to have high detection sensitivity for high-frequency tactile information in the form of vibration. In addition, the magnetic strip of the flexible sensing probe enables the sensor of the present invention to detect magnetically conductive objects. Thanks to the structure and function of the flexible sensing probe, the sensor of the present invention can detect touch and vibration, as well as detect the proximity of magnetically conductive objects, thereby realizing tactile sensing and tactile recognition functions such as touch detection, surface recognition, and material recognition. The sensor of the present invention expands the multi-layer planar structure commonly used in current flexible tactile sensors and enriches the relatively simple stress detection function of current flexible tactile sensors.

[0022] (2) The probe-structure flexible tactile sensor provided by this invention has two working modes: contact and non-contact. In the non-contact working mode, the sensor can identify the material of an object without contacting it. In the contact working mode, the sensor can achieve touch detection or surface recognition by detecting the object's touch process or the surface scanning process. This sensor helps to solve the problem that existing flexible tactile sensors are difficult to achieve tactile recognition and non-contact sensing.

[0023] (3) The fabrication method of the probe-structured flexible tactile sensor provided by the present invention mainly involves printed electronics technology, cutting manufacturing process, and additive manufacturing technology. It does not involve complex processes using vacuum equipment or micro-nano processing equipment. Moreover, the flexible sensing probe, as the main body of the sensor of the present invention, is fixed by adhesive bonding. Therefore, the fabrication process of the present invention has the characteristics of low cost, easy fabrication, high material utilization rate, and high degree of customization. In addition, the probe-structured flexible tactile sensor obtained by the fabrication method of the present invention has the characteristics of multifunctionality, arraying, and wearability, and can be used as a wearable device in robot systems and human-computer interaction devices. Attached Figure Description

[0024] Figure 1 This is an exploded structural diagram of the probe-structured flexible tactile sensor of the present invention;

[0025] Figure 2 This is an overall assembly diagram of the probe structure flexible tactile sensor of the present invention;

[0026] Figure 3 This is a schematic diagram of the layering of the piezoelectric sensing layer of the present invention;

[0027] Figure 4 This is a schematic diagram of an adhesion between a double-sided conductive tape and a flexible piezoelectric film.

[0028] Figure 5 This is a schematic diagram of an adhesion between double-sided conductive tape and a planar electrode.

[0029] Figure 6 A microscope image of a flexible piezoelectric thin film;

[0030] The markings in the figure are as follows: 1. Flexible sensing probe, 2. Flexible substrate layer, 11. Piezoelectric sensing layer, 111. Flexible piezoelectric film, 112. Upper encapsulation layer, 113. Lower encapsulation layer, 12. Magnetic strip, 13. Fixing block, 21. Flexible substrate, 22. Planar electrode, 3. Double-sided conductive tape. Detailed Implementation

[0031] To better understand the purpose, structure, and function of this invention, the following detailed description, in conjunction with the accompanying drawings, provides a probe-structured flexible tactile sensor and its fabrication method.

[0032] like Figure 1 As shown in Figure 5, a flexible tactile sensor with a probe structure according to the present invention includes a flexible sensing probe 1 and a flexible substrate layer 2. The flexible substrate layer 2 includes a planar electrode 22 and a flexible substrate 21. The flexible sensing probe 1 includes a piezoelectric sensing layer 11, a magnetic strip 12, and a fixing block 13. The piezoelectric sensing layer 11 includes a flexible piezoelectric film 111, an upper encapsulation layer 112, and a lower encapsulation layer 113. The flexible piezoelectric film 111 is located between the upper encapsulation layer 112 and the lower encapsulation layer 113, and the flexible piezoelectric film 111 has double-sided electrodes. The flexible sensing probe 1 has a two-section bent flexible probe structure, including a bottom portion and an inclined portion. The connection between the bottom portion and the inclined portion forms a bending angle. The bottom portion of the flexible sensing probe 1 and the... The flexible substrate 2 is bonded and fixed to the surface. The inclined portion of the flexible sensing probe 1 is divided into a free end that can be bent and deformed. The magnetic strip 12 is disposed at the top of the inclined portion of the flexible sensing probe 1 so that the magnetic strip 12 can convert the information of the magnetic object approaching into the deformation information of the flexible sensing probe 1. The fixing block 13 is bonded and fixed to the surface of the flexible substrate 2 and to the bottom of the inclined portion of the flexible sensing probe 1 so that the bending angle of the flexible sensing probe 1 is a fixed value when there is no external stimulation. The planar electrode 22 is disposed on the surface of the flexible substrate 21, and a pair of planar electrodes 22 are connected to a pair of double-sided electrodes of the flexible piezoelectric film 111. The planar electrode 22 outputs the electrical signal of the flexible piezoelectric film 111 to the external circuit.

[0033] The main body of the flexible sensing probe 1 is a flexible piezoelectric sensing layer 11 with piezoelectric sensing function. A magnetic strip 12 is disposed on one or both sides of the top of the piezoelectric sensing layer 11. The magnetic strip 12 is used to detect magnetically conductive objects. A fixing block 13 at the bottom of the flexible sensing probe 1 is used to fix the flexible sensing probe 1. Preferably, the bottom area of ​​the flexible sensing probe 1 is equal to or greater than 20 mm². 2 This ensures a firm bond between the flexible sensing probe 1 and the flexible substrate layer 2. Preferably, the main body of the fixing block 13 has a triangular cross-sectional shape, so that the bending angle of the flexible sensing probe 1 is a fixed value when there is no external stimulus. Preferably, the fixing block 13 has protrusions on both sides, which protrude from both sides of the flexible sensing probe 1, thereby restricting the tangential movement of the flexible sensing probe 1 when subjected to tangential force.

[0034] The number of flexible sensing probes 1 can be one or more. The number of pairs of planar electrodes 22 in the flexible substrate layer 2 is the same as the number of flexible sensing probes 1. Each pair of planar electrodes 22 in the flexible substrate layer 2 is connected to each pair of double-sided electrodes in the flexible sensing probe 1, thereby realizing the output of piezoelectric signals from the flexible sensing probe 1.

[0035] Preferably, the number of flexible sensing probes 1 is equal to or greater than three, forming an array of flexible sensing probes 1. Preferably, the manufacturing process of the array of flexible sensing probes 1 is precision cutting technology, such as laser cutting or mechanical cutting.

[0036] like Figure 1 and Figure 2 As shown, the piezoelectric sensing layer 11 is formed by sequentially stacking and encapsulating an upper encapsulation layer 112, a flexible piezoelectric film 111, and a lower encapsulation layer 113, thereby encapsulating the flexible piezoelectric film 111. Preferably, the flexible piezoelectric film 111 is a polymer piezoelectric film with double-sided metallized electrodes. Preferably, the upper encapsulation layer 112 and the lower encapsulation layer 113 are single-sided adhesive polyethylene terephthalate encapsulation films. Preferably, the upper encapsulation layer 112 and the lower encapsulation layer 113 have the same shape. Preferably, a portion of the flexible piezoelectric film 111 is not encapsulated, thereby connecting the double-sided electrodes of the unencapsulated portion of the flexible piezoelectric film 111 to the planar electrodes 22 of the flexible substrate layer 2.

[0037] The magnetic strip 12 is a polymer elastomer containing magnetic particles, such as ferrite magnet particles, AlNiCo magnet particles, rare earth magnet particles, which are uniformly mixed with an elastic resin, elastic rubber, or silicone and cured before being magnetized to obtain a magnetic elastomer.

[0038] Preferably, the material of the fixing block 13 is a photosensitive resin suitable for photopolymerization 3D printing. Preferably, the manufacturing process of the fixing block 13 is photopolymerization 3D printing.

[0039] Preferably, the material of the planar electrode 22 is a material that can be formulated into conductive ink, such as one or more of metal nanowires, metal nanoparticles, metallic carbon nanotubes, and conductive polymers. Preferably, the manufacturing process of the planar electrode 22 is a printed electronics process. Preferably, double-sided conductive tape 3 is used to connect the planar electrode 22 to the double-sided electrode.

[0040] The following specific embodiment further illustrates the fabrication method of the flexible tactile sensor with probe structure of the present invention, specifically including:

[0041] (1) Fabrication of piezoelectric sensing layer 11: A polymer piezoelectric film with a thickness of 50 μm and double-sided silver paste electrodes is selected as the flexible piezoelectric film 111. The flexible piezoelectric film 111 is cut into a pre-designed pattern using a mechanical cutter (see the specific pattern for reference). Figure 3 Cutting is performed as shown. A polyethylene terephthalate (PET) encapsulation film with a thickness of 80 μm and single-sided adhesive is selected as the upper encapsulation layer 112 and the lower encapsulation layer 113. A mechanical cutter is used to cut both the upper encapsulation layer 112 and the lower encapsulation layer 113 according to a pre-designed pattern (see attached diagram). Figure 3 Cut the upper encapsulation layer 112 (as shown) to ensure that the upper encapsulation layer 112 and the lower encapsulation layer 113 have the same shape. Align the upper encapsulation layer 112, the flexible piezoelectric film 111, and the lower encapsulation layer 113 sequentially from top to bottom (refer to [reference for specific alignment method]). Figure 3 As shown in the figure, during the stacking process, the adhesive side of the upper encapsulation layer 112 should be directly aligned with the adhesive side of the lower encapsulation layer 113, and a portion of the flexible piezoelectric film 111 should not be stacked. Then, the stacked upper encapsulation layer 112, flexible piezoelectric film 111, and lower encapsulation layer 113 are laminated to complete the encapsulation. This step yields the piezoelectric sensing layer 11. Figure 6 This is a partial microscope image of a flexible piezoelectric thin film, showing that the surface of the flexible piezoelectric thin film has silver paste electrodes.

[0042] (2) Fabrication of flexible sensing probe 1: The piezoelectric sensing layer 11 is mechanically bent (the specific bending method and bending angle are referred to Figure 1 and Figure 2 As shown), a two-section bent flexible probe structure is formed. A magnetic elastomer formed from ferrite magnet particles and elastic resin is selected as the magnetic strip 12, with the magnetization direction of the magnetic strip 12 perpendicular to its bottom surface. Room temperature vulcanizing silicone rubber is used to bond the magnetic strip 12 to the surface of the upper encapsulation layer 112 of the piezoelectric sensing layer 11. During bonding, the magnetic strip 12 should be positioned at the top of the piezoelectric sensing layer 11 (see [reference] for specific bonding methods). Figure 1 and Figure 2 As shown). Using a stereolithography 3D printer with stereolithography capabilities, the photosensitive resin is pressed into a pre-designed structure (see attached image for details). Figure 1 and Figure 2 (As shown) 3D printing is performed to obtain fixing block 13. The main body of fixing block 13 has a triangular cross-sectional shape, and protrusions are provided on both sides of fixing block 13. Fixing block 13 is bonded to the surface of the lower encapsulation layer 113 of piezoelectric sensing layer 11 using room temperature vulcanizing silicone rubber. During bonding, the bottom surface of fixing block 13 and the bottom surface of piezoelectric sensing layer 11 should be on the same plane (see [reference] for specific bonding method). Figure 1 and Figure 2 (As shown). This step yields the flexible sensing probe 1.

[0043] (3) Fabrication of the flexible substrate 2: A 100 μm thick polyethylene naphthalate film was selected as the flexible substrate 21, and the flexible substrate 21 was cut using a mechanical cutter. Conductive ink was printed using a microelectronic inkjet printer according to the pre-designed planar electrode 22 pattern (see the specific pattern for reference). Figure 5 (As shown) The conductive ink is printed onto the surface of the flexible substrate 21. The flexible substrate 21 with the printed conductive ink is heated to cure the conductive ink, thereby forming a planar electrode 22. This step yields the flexible substrate layer 2.

[0044] (4) Bonding of the probe array: Repeat steps (1) and (2) twice to obtain three flexible sensing probes 1 with the same structure. In each flexible sensing probe 1, a pair of double-sided conductive tapes 3 are bonded to the upper and lower surfaces of the unencapsulated portion of the flexible piezoelectric film 111 (refer to the specific bonding method). Figure 4 (As shown). Each flexible sensing probe 1 is bonded to the side of the flexible substrate 2 with planar electrodes 22 using room temperature vulcanizing silicone rubber. During bonding, the bottom surface of the flexible sensing probe 1 should be in contact with the surface of the flexible substrate 2. Also during bonding, a pair of double-sided conductive tapes 3 on the surface of the flexible piezoelectric film 111 should be in contact with a pair of planar electrodes 22 of the flexible substrate 2 (see [reference for specific bonding method]). Figure 5 (As shown). This step yields a probe-structured flexible tactile sensor.

[0045] The method of using and the working process of the flexible tactile sensor with probe structure of the present invention are as follows:

[0046] The basic principle of the probe-structure flexible tactile sensor is to convert external physical stimuli, including touch, vibration, and proximity of a magnetically conductive object, into deformation of the piezoelectric sensing layer 11 through the flexible probe structure and magnetic strip 12, thereby outputting a piezoelectric signal. The probe-structure flexible tactile sensor operates in two modes: non-contact and contact. In non-contact mode, it can detect the proximity of a magnetically conductive object; in contact mode, it can detect touch and vibration. The functions of the probe-structure flexible tactile sensor include material recognition, touch detection, and surface recognition. The following section details the operation of the probe-structure flexible tactile sensor for these functions.

[0047] When performing material identification, the probe-structured flexible tactile sensor can be attached to the end effector of a robotic arm. The robotic arm is then manipulated to bring the probe-structured flexible tactile sensor closer to the object being detected without making contact. By detecting the output signal of the probe-structured flexible tactile sensor during this process, non-contact identification of the object's material can be achieved: when the object being detected is a non-magnetic material, the amplitude of the piezoelectric signal output by the probe-structured flexible tactile sensor is zero; when the object being detected is a magnetic material, the approach of the object causes the magnetic strip 12 to be subjected to magnetic force, which in turn causes the flexible sensing probe 1 containing the flexible piezoelectric film 111 to deform, and the probe-structured flexible tactile sensor outputs a piezoelectric signal with a slowly changing amplitude. The sensor operating mode corresponding to this function is non-contact.

[0048] When performing the touch detection function, a flexible tactile sensor with a probe structure can be attached to the periphery of a mobile robot. As the robot moves, it continuously monitors the output signal of the flexible tactile sensor to detect object contact: when the object is not in contact with the sensor, the amplitude of the piezoelectric signal output is zero; when the object comes into contact with the sensor, the flexible sensing probe 1, which includes the flexible piezoelectric film 111, deforms, and the sensor outputs a piezoelectric signal with continuously changing amplitude. The sensor's operating mode for this function is contact-based.

[0049] When performing surface recognition, a flexible tactile sensor with a probe structure can be attached to the fingertip of a robotic arm. The robotic arm is then manipulated to bring the flexible sensing probe 1 into contact with the surface to be detected, while the flexible substrate 2 remains in contact. The surface to be detected is planar. The robotic arm is then moved to allow the flexible tactile sensor to scan the surface, i.e., to move at a constant speed along a direction parallel to the surface. By detecting and analyzing the output signal of the flexible tactile sensor during this scanning process, surface roughness can be identified: When the surface is smooth, the deformation of the flexible sensing probe 1 remains essentially constant during the scanning process, and the flexible tactile sensor outputs virtually no piezoelectric signal; when the surface is rough, the deformation of the flexible sensing probe 1 undergoes reciprocating changes during the scanning process, and the flexible tactile sensor outputs a piezoelectric signal with reciprocating amplitude. The sensor operating mode for this function is contact-based.

[0050] It is understood that the present invention has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the invention. Furthermore, under the teachings of the present invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of the present invention.

Claims

1. A probe structure flexible tactile sensor characterized by, The system includes a flexible sensing probe (1) and a flexible substrate (2). The flexible sensing probe (1) is a two-section bent flexible probe structure, including a bottom part and an inclined part. The bottom part and the inclined part are connected to form a bending angle. The bottom part of the flexible sensing probe (1) is bonded and fixed to the surface of the flexible substrate (2). The inclined part of the flexible sensing probe (1) is divided into a free end that can be bent and deformed. The contact of the object is transformed into the deformation of the flexible sensing probe (1). The top of the inclined part of the flexible sensing probe (1) has a magnetic strip (12). The magnetic strip (12) transforms the approach of the magnetically conductive object into the deformation of the flexible sensing probe (1). The flexible substrate (2) is used to convert the deformation information of the flexible sensing probe (1) into an electrical signal and transmit it to the external circuit.

2. The probe structure flexible tactile sensor of claim 1, wherein, Includes a fixing block (13), which is fixed on the surface of the flexible substrate layer (2) and bonded to the bottom of the inclined portion of the flexible sensing probe (1) so that the bending angle of the flexible sensing probe (1) is a fixed value when it is not stimulated by external factors.

3. The probe structure flexible tactile sensor of claim 2, wherein, The flexible substrate (2) includes a planar electrode (22) and a flexible substrate (21). The planar electrode (22) is disposed on the surface of the flexible substrate (21). The main body of the flexible sensing probe (1) is a piezoelectric sensing layer (11) that is flexible and has piezoelectric sensing function. The magnetic strip (12) is disposed on one or both sides of the top of the piezoelectric sensing layer (11). The piezoelectric sensing layer (11) includes a flexible piezoelectric film (111), an upper encapsulation layer (112), and a lower encapsulation layer (113). The flexible piezoelectric film (111) is located between the upper encapsulation layer (112) and the lower encapsulation layer (113). The flexible piezoelectric film (111) has a double-sided electrode, which is connected to the planar electrode (22) of the flexible substrate (2).

4. The probe-structured flexible tactile sensor according to claim 1, characterized in that, The flexible sensing probe (1) has a bottom surface area equal to or greater than 20 mm 2 .

5. The probe-structured flexible tactile sensor according to claim 2, characterized in that, The main body of the fixing block (13) has a triangular cross-sectional shape. The fixing block (13) has protrusions on both sides. The protrusions protrude on both sides of the flexible sensing probe (1) to restrict the tangential movement of the flexible sensing probe (1).

6. The probe-structured flexible tactile sensor according to claim 3, characterized in that, The flexible piezoelectric film (111) is a polymer piezoelectric film with double-sided metallized electrodes. The upper encapsulation layer (112) and the lower encapsulation layer (113) are single-sided adhesive polymer encapsulation films. The magnetic strip (12) is a polymer elastomer containing magnetic microparticles. The material of the fixing block (13) is a resin suitable for three-dimensional printing. The material of the planar electrode (22) is a material that can be formulated into conductive ink.

7. The probe-structured flexible tactile sensor according to claim 1, characterized in that, The flexible sensing probe (1) is one or more, and the number of pairs of planar electrodes (22) in the flexible substrate (2) is the same as the number of flexible sensing probes (1). Each pair of planar electrodes (22) in the flexible substrate (2) is connected to each pair of double-sided electrodes in the flexible sensing probe (1).

8. The probe-structured flexible tactile sensor according to claim 1, characterized in that, The number of flexible sensing probes (1) is equal to or greater than three, forming a flexible sensing probe (1) array.

9. The probe-structured flexible tactile sensor according to claim 3, characterized in that, The planar electrode (22) of the flexible substrate (2) is connected to the double-sided electrode of the flexible piezoelectric film (111) using double-sided conductive tape (3).

10. A method for fabricating a probe-structured flexible tactile sensor according to any one of claims 1-9, characterized in that, The steps include the following: Step 1: Manufacturing of piezoelectric sensing layer (11): Cut the flexible piezoelectric film (111), upper encapsulation layer (112), and lower encapsulation layer (113), stack the upper encapsulation layer (112), flexible piezoelectric film (111), and lower encapsulation layer (113) in sequence and encapsulate them to obtain the piezoelectric sensing layer. Step 2: Fabrication of flexible sensing probe (1): The piezoelectric sensing layer (11) is mechanically bent to form a two-section bent flexible probe structure. A magnetic strip (12) is bonded to the top of the piezoelectric sensing layer (11), and a fixing block (13) is bonded to the bottom of the piezoelectric sensing layer (11) to obtain the flexible sensing probe (1). Step 3: Fabrication of flexible substrate (2): A planar electrode array is fabricated on the surface of the flexible substrate (21) to obtain the flexible substrate (2). Step 4: Bonding of the probe array: Bond the bottom surface of the flexible sensing probe (1) to the surface of the flexible substrate layer (2), and connect a pair of double-sided electrodes of the flexible piezoelectric film (111) to a pair of planar electrodes of the flexible substrate layer (2) to obtain a probe structure flexible tactile sensor.

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