Tactile sensor and preparation method and detection method thereof

Abstract

This application discloses a tactile sensor and its fabrication and detection methods. The tactile sensor, from top to bottom, comprises a rubber protective layer, a capacitive sensor, a single-sided conductive film, and a piezoresistive sensor. The non-conductive surface of the single-sided conductive film is in contact with the capacitive sensor, while the conductive surface faces the piezoresistive sensor. The film has an array-type micro-protrusion structure. The capacitive sensor detects the proximity of the object being measured, while the single-sided conductive film and the piezoresistive sensor monitor the magnitude and distribution of pressure. This application enables the identification of the proximity of objects and the monitoring of the magnitude and distribution of minute pressures. It can be widely applied in the field of sensor fabrication technology.

Description

Technical Field

[0001] This application relates to the field of sensor fabrication technology, and in particular to a tactile sensor and its fabrication and detection methods. Background Technology

[0002] While current sensors on the market can be used for pressure monitoring, their sensitivity is low, making them unable to monitor small pressures. Furthermore, most are single-mode sensors, which can only monitor force, resulting in limited functionality. Additionally, existing sensor materials and electrodes have poor adaptability and are expensive, making them unsuitable for the non-planar and bending applications of mechanical fingers. Summary of the Invention

[0003] To address the aforementioned technical problems, the purpose of this application is to provide a tactile sensor and its preparation and detection methods, which can monitor minute pressures and detect contact.

[0004] To achieve the above objectives, one aspect of this application proposes a tactile sensor, which, from top to bottom, includes a rubber protective layer, a capacitive sensor, a single-sided conductive film, and a piezoresistive sensor. The non-conductive surface of the single-sided conductive film is in contact with the capacitive sensor, and the conductive surface of the single-sided conductive film faces the piezoresistive sensor and has an array-type micro-protrusion structure. The capacitive sensor is used to detect the proximity of the object being measured, and the single-sided conductive film and the piezoresistive sensor are used to monitor the magnitude and distribution of pressure.

[0005] In some embodiments, the tactile sensor further includes a capacitance detection circuit, a microprocessor, and a plurality of pull-up resistors. The capacitance detection circuit is connected to the capacitive sensor, and each of the pull-up resistors is connected to the piezoresistive sensor. The capacitance detection circuit, the piezoresistive sensor, and each of the pull-up resistors are also connected to the microprocessor.

[0006] In some embodiments, the single-sided conductive film comprises, from top to bottom, a polydimethylsiloxane layer and a graphene conductive layer.

[0007] In some embodiments, the capacitive sensor comprises, from top to bottom, an insulating layer and a capacitive sensing electrode.

[0008] In some embodiments, the piezoresistive sensor comprises, from top to bottom, a resistance sensing electrode array and an insulating layer.

[0009] In some embodiments, the resistance sensing electrode array includes 8×12 resistance sensing electrodes arranged in an 8-column 12-row configuration, with a spacing of 0.15 mm between each resistance sensing electrode.

[0010] In some embodiments, the insulating layer is made of polyimide.

[0011] To achieve the above objectives, another aspect of this application proposes a method for fabricating a tactile sensor, comprising the following steps: Fabrication of single-sided conductive thin films, piezoresistive sensors, and capacitive sensors; The conductive surface of the single-sided conductive film is placed facing the piezoresistive sensor; The capacitive sensor is placed on the non-conductive surface of the single-sided conductive film to obtain a sandwich structure; A tactile sensor is obtained by encapsulating the sandwich structure with a rubber protective layer.

[0012] In some embodiments, the preparation of the single-sided conductive thin film specifically includes: Graphene nanosheets were placed in a centrifuge tube, and ethanol was added for ultrasonic dispersion to obtain a graphene suspension. The graphene suspension was placed in a centrifuge tube, diluted with ethanol, and then sprayed onto an acrylic plate with an array of micro-concave structures to obtain a graphene conductive layer. A mixture is obtained by mixing a liquid polydimethylsiloxane precursor and a curing agent; The mixture was poured onto a polytetrafluoroethylene plate to obtain a polydimethylsiloxane layer; The polydimethylsiloxane layer is coated onto the graphene conductive layer, cured, and then peeled off from the acrylic sheet to obtain the single-sided conductive film.

[0013] To achieve the above objectives, another aspect of this application proposes a detection method for a tactile sensor, comprising the following steps: The equivalent capacitance between the capacitive sensor and the object being measured is obtained through a capacitance detection circuit. The proximity of the object under test is obtained by a microprocessor based on the equivalent capacitance. The microprocessor obtains the contact resistance between the single-sided conductive film and the piezoresistive sensor, generates an input voltage based on the contact resistance and the pull-up resistor, and then obtains the magnitude and distribution of the pressure based on the input voltage.

[0014] The beneficial effects of this application are as follows: The tactile sensor and its preparation and detection methods of this application include, from top to bottom, a rubber protective layer, a capacitive sensor, a single-sided conductive film, and a piezoresistive sensor. The non-conductive surface of the single-sided conductive film is in contact with the capacitive sensor, and the conductive surface of the single-sided conductive film faces the piezoresistive sensor and has an arrayed micro-protrusion structure. The capacitive sensor is used to detect the proximity of the object being measured, and the single-sided conductive film and the piezoresistive sensor are used to monitor the magnitude and distribution of pressure. This application combines a capacitive sensor and a piezoresistive sensor, enabling the identification of the proximity of an object and the monitoring of pressure magnitude and distribution; furthermore, the addition of an arrayed micro-protrusion structure to the conductive surface of the single-sided conductive film increases the sensor's sensitivity to force monitoring, enabling the monitoring of minute pressures. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the embodiments of this application are described below. It should be understood that the drawings described below are only for the purpose of clearly illustrating some embodiments of the technical solutions in this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0016] Figure 1 A schematic diagram of the cross-sectional structure of a tactile sensor provided in one embodiment of this application; Figure 2 A schematic diagram of the cross-sectional structure of a tactile sensor provided in another embodiment of this application; Figure 3 This is a top PCB wiring diagram of a tactile sensor provided in one embodiment of this application; Figure 4 This is a bottom PCB wiring diagram of a tactile sensor provided in one embodiment of this application; Figure 5 A circuit schematic diagram of a tactile sensor provided in one embodiment of this application; Figure 6 This is a flowchart illustrating the steps of a method for fabricating a tactile sensor according to an embodiment of this application. Figure 7 This is a flowchart illustrating the steps of a tactile sensor detection method according to one embodiment of this application.

[0017] Reference numerals: 10, rubber protective layer; 20, capacitive sensor; 30, single-sided conductive film; 40, piezoresistive sensor; 201, insulating layer; 202, capacitive sensing electrode; 301, polydimethylsiloxane layer; 302, graphene conductive layer; 401, resistive sensing electrode array. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit it. In the following description, when referring to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with those of this application; they are merely examples of apparatuses and methods consistent with some aspects of the embodiments of this application as detailed in the appended claims.

[0019] It is understood that the terms “first,” “second,” etc., used in this application may be used to describe various concepts herein, but unless otherwise stated, these concepts are not limited by these terms. These terms are used only to distinguish one concept from another.

[0020] As used in this application, the terms "at least one", "multiple", "each", "any", etc., "at least one" includes one, two or more, "multiple" includes two or more, "each" refers to each of the corresponding multiples, and "any" refers to any one of the multiples.

[0021] While the sensors currently available on the market can be used for pressure monitoring, their sensitivity is not high, they cannot monitor small pressures, and most are single-mode sensors, which can only monitor force, resulting in limited functionality.

[0022] In view of this, this application proposes a tactile sensor, which, from top to bottom, includes a rubber protective layer, a capacitive sensor, a single-sided conductive film, and a piezoresistive sensor. The non-conductive surface of the single-sided conductive film contacts the capacitive sensor, while the conductive surface faces the piezoresistive sensor and has an arrayed micro-protrusion structure. The capacitive sensor is used to detect the proximity of the object being measured, while the single-sided conductive film and the piezoresistive sensor are used to monitor the magnitude and distribution of pressure. This application combines a capacitive sensor and a piezoresistive sensor, enabling the identification of the proximity of an object and the monitoring of pressure magnitude and distribution. Furthermore, the addition of an arrayed micro-protrusion structure to the conductive surface of the single-sided conductive film increases the sensor's sensitivity to force monitoring, enabling the monitoring of minute pressures. Further, the resistive and capacitive sensors can be integrated into a mechanical finger using a sandwich structure to achieve the identification of the proximity of an object and the monitoring of pressure magnitude and distribution.

[0023] Reference Figure 1 , Figure 1This is a cross-sectional structural diagram of a tactile sensor provided in one embodiment of this application. The embodiment of this application proposes a tactile sensor, which includes, from top to bottom, a rubber protective layer 10, a capacitive sensor 20, a single-sided conductive film 30, and a piezoresistive sensor 40. The non-conductive surface of the single-sided conductive film 30 is in contact with the capacitive sensor 20, and the conductive surface of the single-sided conductive film 30 faces the piezoresistive sensor 40. It has an array-type micro-protrusion structure. The capacitive sensor 20 is used to detect the proximity of the object being measured, and the single-sided conductive film 30 and the piezoresistive sensor 40 are used to monitor the magnitude and distribution of pressure.

[0024] Specifically, this application provides a tactile sensor consisting of two parts: an upper capacitive sensor for non-contact object sensing (detecting the proximity of objects) and a lower piezoresistive sensor for sensing pressure magnitude and analyzing force distribution; a flexible, single-sided conductive film serves as a pressure-sensitive layer between the two sensors. The non-conductive surface of the conductive film contacts the capacitive sensor, while the conductive surface faces the piezoresistive sensor. The conductive film also features an array of micro-protrusions to increase the sensor's sensitivity to force detection.

[0025] It should be noted that the tactile sensor in this application combines a capacitive sensor and a piezoresistive sensor, enabling the identification of the proximity of an object and the monitoring of pressure magnitude and distribution.

[0026] Reference Figure 2 , Figure 2 This is a cross-sectional structural diagram of a tactile sensor provided in another embodiment of this application. Further, as an optional implementation, the single-sided conductive film 30 includes, from top to bottom, a polydimethylsiloxane layer 301 and a graphene conductive layer 302.

[0027] Specifically, the single-sided conductive film includes a polydimethylsiloxane layer and an array of micro-protrusions forming a graphene conductive layer. The polydimethylsiloxane layer acts as an insulator to prevent the graphene conductive layer from contacting the capacitive sensor; the graphene conductive layer serves as a conductive pathway, allowing it to contact the piezoresistive sensor under pressure, thus enabling the monitoring of pressure magnitude and distribution.

[0028] Reference Figure 2 As an optional implementation, the capacitive sensor 20 includes, from top to bottom, an insulating layer 201 and a capacitive sensing electrode 202.

[0029] Specifically, the capacitive sensing electrode is equivalent to one plate of a parallel plate capacitor. When the object being measured approaches, the object is equivalent to the other plate of the parallel plate capacitor or changes the dielectric constant of the electric field region, increasing the equivalent capacitance between the two plates. The proximity of the object can then be detected based on this equivalent capacitance.

[0030] Reference Figure 2 As an optional implementation, the piezoresistive sensor 40 includes, from top to bottom, a resistance sensing electrode array 401 and an insulating layer 201.

[0031] Specifically, when the sensor is subjected to force, the single-sided conductive film (i.e., the pressure-sensitive layer) will come into contact with the resistive sensing electrode array below, causing a change in contact resistance. As the pressure increases, the pressure-sensitive layer is compressed, and the change in contact resistance becomes greater, thereby enabling pressure monitoring.

[0032] As a further optional implementation, the insulating layer is made of polyimide.

[0033] As a further optional implementation, the resistance sensing electrode array includes 8×12 resistance sensing electrodes arranged in an 8-column 12-row configuration, with a spacing of 0.15 mm between each resistance sensing electrode.

[0034] In some alternative embodiments, such as Figure 3 The diagram shown is the top PCB layout of the tactile sensor. Figure 4 The diagram shows the bottom PCB layout of the tactile sensor. The resistive sensing array is an 8×12 array, with each row connected together on the bottom surface and each column connected together on the top surface. Each resistive sensing electrode is a square with a side length of 1 mm, and the spacing between electrodes is 0.15 mm. When pressure is applied above the resistive sensing array, the single-sided conductive film deforms and comes into contact with the resistive array, thereby changing the resistance value between adjacent electrodes. Based on the resistance value between each resistive sensing electrode and the array of micro-protrusions, the pressure distribution across the entire plane can be scanned.

[0035] The capacitive sensing electrode has a diameter of 8mm and consists of four 90-degree sector-shaped electrodes symmetrically distributed around their centers. When the capacitive sensing electrode approaches a conductive object, the sensor electrode and the conductive object form a parallel-plate capacitor. The capacitance is inversely proportional to the distance between the plates, thus enabling the detection of the object's proximity.

[0036] As a further optional implementation, the tactile sensor also includes a capacitance detection circuit, a microprocessor, and multiple pull-up resistors. The capacitance detection circuit is connected to a capacitive sensor, and each pull-up resistor is connected to a piezoresistive sensor. The capacitance detection circuit, the piezoresistive sensor, and each pull-up resistor are also connected to the microprocessor.

[0037] Specifically, such as Figure 5The diagram shows the circuit schematic of the tactile sensor. Each row of resistive sensing electrodes in the resistive sensing electrode array is connected to the microprocessor's I / O port. Each column of resistive sensing electrodes is connected together and connected to the analog power supply voltage via a fixed-value pull-up resistor, and also connected to one of the microprocessor's ADC input terminals. The four channels of the capacitive sensing electrodes are connected to a capacitance detection circuit, which is connected to the microprocessor's IIC port.

[0038] It should be noted that capacitive sensing is a low-power, low-cost, and high-resolution non-contact sensing technology suitable for a wide range of applications, from proximity detection and gesture recognition to remote liquid level sensing. The sensors in capacitive sensing systems can be made of any metal or conductor, thus enabling highly flexible and low-cost system designs.

[0039] In some optional embodiments, the capacitance sensing circuit employs a capacitance-to-digital converter (FDC2214) for capacitance sensing. Compared to traditional switched-capacitor structures, the FDC2214 uses an LC resonator, also known as an LC resonant cavity, as the sensor. Compared to other capacitance sensing solutions, the narrowband structure offers strong electromagnetic interference immunity and significantly reduces noise floor. Using this method, the capacitance change of the LC resonant cavity, i.e., the shift in the resonant frequency, can be observed. Utilizing this principle, the FDC chip outputs a digital value proportional to the frequency, which can be converted into an equivalent capacitance.

[0040] The structure and working principle of the tactile sensor according to the embodiments of this application have been described above. It can be recognized that, compared with existing sensors, the embodiments of this application have the following advantages: First, it combines capacitive and piezoresistive sensors, enabling the identification of the proximity of objects and the monitoring of pressure magnitude and distribution, while reducing design costs.

[0041] Second, adding an array of micro-protrusion structures to the conductive surface of a single-sided conductive film can increase the sensor's sensitivity to force monitoring, enabling the monitoring of minute pressures.

[0042] Third, the entire sensor uses flexible materials and electrodes, which can be bent to a certain extent, making it suitable for non-planar and bending applications such as bionic robot fingers.

[0043] Reference Figure 6 , Figure 6 This is a flowchart illustrating the steps of a method for fabricating a tactile sensor according to one embodiment of this application. This application also provides a method for fabricating a tactile sensor, including the following steps S101 to S104: Step S101: Prepare a single-sided conductive thin film, a piezoresistive sensor, and a capacitive sensor; Step S102: Place the conductive side of the single-sided conductive film facing the piezoresistive sensor; Step S103: Place the capacitive sensor on the non-conductive surface of the single-sided conductive film to obtain a sandwich structure; Step S104: Encapsulate the sandwich structure with a rubber protective layer to obtain a tactile sensor.

[0044] Specifically, a single-sided conductive film and flexible sensing electrodes (capacitive sensing electrodes and resistive sensing electrode arrays) are first prepared. The single-sided conductive film is placed on the resistive sensing electrode array with the conductive side facing the resistive sensing array. Then, the capacitive sensing electrode is covered on the non-conductive side of the single-sided conductive film to form a sandwich structure. Finally, the electrodes and conductive film are encapsulated with a finger-shaped rubber protective layer to obtain a tactile sensor.

[0045] As an optional implementation, the step of preparing a single-sided conductive film can be further divided into the following steps S1011 to S1015: Step S1011: Place graphene nanosheets in a centrifuge tube, add ethanol and disperse by ultrasonication to obtain a graphene suspension; Step S1012: Place the graphene suspension in a centrifuge tube, add ethanol to dilute it, and then spray the diluted graphene suspension onto an acrylic plate with an array of micro-concave structures to obtain a graphene conductive layer. Step S1013: Mix the liquid polydimethylsiloxane precursor and the curing agent to obtain a mixture; Step S1014: The mixture is poured onto a polytetrafluoroethylene plate to obtain a polydimethylsiloxane layer; Step S1015: Cover the graphene conductive layer with a polydimethylsiloxane layer, and peel it off from the acrylic sheet after curing to obtain a single-sided conductive film.

[0046] For example, firstly, an array of micro-concave structures is engraved on an acrylic sheet using a laser engraving machine, and the sheet is preheated on a heater (70°C). A certain amount of graphene nanosheets is placed in a 50mL centrifuge tube, and an appropriate amount of ethanol is added and ultrasonically dispersed for 10 minutes to obtain a uniform graphene nanosheet ethanol suspension with a concentration of 2mg / mL (i.e., graphene suspension). Then, another 50mL centrifuge tube is used to dilute the graphene suspension with ethanol (1:3, V / V). The diluted suspension is then poured into a spray gun with a nozzle size of 0.2mm, and the suspension is evenly sprayed onto the acrylic sheet under a pressure of 50psi. After spraying, the mask is peeled off the acrylic sheet. A mixture of the prepared liquid PDMS precursor (i.e., liquid polydimethylsiloxane precursor) and curing agent (substrate to crosslinking agent mass ratio of 10:1) is poured onto the polytetrafluoroethylene (PTFE) sheet. A glass rod with a transparent rubber ring (approximately 1 mm thick) is used to spread the mixture, ensuring the liquid PDMS precursor and curing agent are evenly coated on the graphene electrode. Finally, the acrylic sheet is cured at 80°C for 30 minutes. After curing, the uniformly conductive electrode is peeled off the acrylic sheet and cut to the required size to obtain a single-sided conductive film.

[0047] It should be noted that the capacitive sensing electrode and resistive sensing electrode array of the embodiments of this application can be mass-produced using commercial FPC fabrication technology, which has the advantages of mature technology and low cost; the single-sided conductive film with array-type micro-concave structure is made by casting, which is simple in process and easy to mass-produce.

[0048] The contents of the above-described tactile sensor embodiments are all applicable to the present preparation method embodiments. The specific functions implemented in the present preparation method embodiments are the same as those in the above-described tactile sensor embodiments, and the beneficial effects achieved are also the same as those achieved in the above-described tactile sensor embodiments.

[0049] Reference Figure 7 , Figure 7 This is a flowchart illustrating the steps of a tactile sensor detection method according to one embodiment of this application. This application also provides a tactile sensor detection method, including the following steps S201 to S203: Step S201: Obtain the equivalent capacitance between the capacitive sensor and the object being measured through the capacitance detection circuit; Step S202: The proximity of the object to be measured is obtained by the microprocessor based on the equivalent capacitance; Step S203: The microprocessor obtains the contact resistance between the single-sided conductive film and the piezoresistive sensor, generates an input voltage based on the contact resistance and the pull-up resistor, and then obtains the magnitude and distribution of the pressure based on the input voltage.

[0050] Specifically, such as Figure 5 As shown, the four channels of the capacitive sensing electrode are connected to the capacitance detection circuit. Each capacitance detection electrode acts as one plate of a parallel plate capacitor, and the object being measured acts as the other plate. Therefore, the capacitance value is inversely proportional to the distance between the two plates. Under the control of the microprocessor, the capacitance detection circuit detects the capacitance value (i.e., equivalent capacitance) between each capacitance sensing electrode and the object being measured. When the sensor is close to but not in contact with the object, the distance between the object and the sensor can be calculated. Furthermore, when the sensor comes into contact with the object, the rubber protective layer between the sensor and the object deforms under pressure, and the pressure can be calculated from the change in capacitance value.

[0051] During resistive sensing electrode detection, the microprocessor's I / O ports sequentially set each row to low voltage. If pressure is applied to the single-sided conductive film, the film contacts the surfaces of adjacent resistive sensing electrodes, generating a contact resistance proportional to the pressure. This contact resistance is connected in series with a fixed-value pull-up resistor between the high voltage (analog power supply) and the low voltage (ground), thus generating an input voltage at the ADC input. The magnitude of this input voltage is inversely proportional to the contact resistance, i.e., inversely proportional to the pressure magnitude, thereby enabling pressure monitoring. By sequentially setting each row to low voltage via the microprocessor's I / O ports and synchronously acquiring data with the ADC, the pressure distribution across the entire plane can be scanned. When there is no pressure, the contact resistance between the conductive film and the resistive sensing electrodes is zero, and no current flows between the high and low voltages, resulting in no additional power consumption.

[0052] It is understandable that each measurement by the resistor array and capacitor array results in one frame, and the resistor array and capacitor array can respectively obtain the planar distribution of pressure. During continuous detection, the direction of pressure change can be calculated from the pressure distribution changes between two or more consecutive frames.

[0053] The contents of the above-described tactile sensor embodiments are all applicable to the embodiments of this detection method. The specific functions implemented by the embodiments of this detection method are the same as those of the above-described tactile sensor embodiments, and the beneficial effects achieved are also the same as those achieved by the above-described tactile sensor embodiments.

[0054] In the foregoing description of this specification, the references to terms such as "one embodiment," "another embodiment," or "some embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0055] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

[0056] The above is a detailed description of the preferred embodiments of this application, but this application is not limited to the embodiments. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of this application, and these equivalent modifications or substitutions are all included within the scope defined by the claims of this application.

Claims

1. A tactile sensor characterized by, From top to bottom, it includes a rubber protective layer, a capacitive sensor, a single-sided conductive film, and a piezoresistive sensor. The non-conductive surface of the single-sided conductive film is in contact with the capacitive sensor, and the conductive surface of the single-sided conductive film faces the piezoresistive sensor. It has an array-type micro-protrusion structure. The capacitive sensor is used to detect the proximity of the object being measured, and the single-sided conductive film and the piezoresistive sensor are used to monitor the magnitude and distribution of pressure.

2. The tactile sensor according to claim 1, characterized by The tactile sensor also includes a capacitance detection circuit, a microprocessor, and multiple pull-up resistors. The capacitance detection circuit is connected to the capacitive sensor, and each of the pull-up resistors is connected to the piezoresistive sensor. The capacitance detection circuit, the piezoresistive sensor, and each of the pull-up resistors are also connected to the microprocessor.

3. The tactile sensor according to claim 1, wherein The single-sided conductive film comprises, from top to bottom, a polydimethylsiloxane layer and a graphene conductive layer.

4. The tactile sensor according to claim 1, characterized by, The capacitive sensor comprises, from top to bottom, an insulating layer and a capacitive sensing electrode.

5. The tactile sensor according to claim 1, wherein The piezoresistive sensor comprises, from top to bottom, a resistance sensing electrode array and an insulating layer.

6. The tactile sensor according to claim 5, wherein The resistance sensing electrode array includes 8×12 resistance sensing electrodes, which are arranged in 8 columns and 12 rows, with a spacing of 0.15 mm between each resistance sensing electrode.

7. The tactile sensor according to any one of claims 4 or 5, wherein The insulating layer is made of polyimide.

8. A method for producing a tactile sensor for producing a tactile sensor according to any one of claims 1 to 7, characterized by, Includes the following steps: Fabrication of single-sided conductive thin films, piezoresistive sensors, and capacitive sensors; The conductive surface of the single-sided conductive film is placed facing the piezoresistive sensor; The capacitive sensor is placed on the non-conductive surface of the single-sided conductive film to obtain a sandwich structure; A tactile sensor is obtained by encapsulating the sandwich structure with a rubber protective layer.

9. The production method according to claim 8, characterized by, The preparation of the single-sided conductive thin film specifically includes: Graphene nanosheets were placed in a centrifuge tube, and ethanol was added for ultrasonic dispersion to obtain a graphene suspension. The graphene suspension was placed in a centrifuge tube, diluted with ethanol, and then sprayed onto an acrylic plate with an array of micro-concave structures to obtain a graphene conductive layer. A mixture is obtained by mixing a liquid polydimethylsiloxane precursor and a curing agent; The mixture was poured onto a polytetrafluoroethylene plate to obtain a polydimethylsiloxane layer; The polydimethylsiloxane layer is coated onto the graphene conductive layer, cured, and then peeled off from the acrylic sheet to obtain the single-sided conductive film.

10. A detection method of a tactile sensor, implemented by the tactile sensor according to any one of claims 1 to 7, characterized by, Includes the following steps: The equivalent capacitance between the capacitive sensor and the object being measured is obtained through a capacitance detection circuit. The proximity of the object under test is obtained by a microprocessor based on the equivalent capacitance. The microprocessor obtains the contact resistance between the single-sided conductive film and the piezoresistive sensor, generates an input voltage based on the contact resistance and the pull-up resistor, and then obtains the magnitude and distribution of the pressure based on the input voltage.

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