Coding-based low-misrecognition triboelectric tactile sensor and preparation method thereof

Abstract

The invention discloses a coding-based low-misrecognition triboelectric tactile sensor and a preparation method thereof.The coding-based low-misrecognition triboelectric tactile sensor sequentially comprises a conductive shielding layer, a triboelectric layer, an electrode and circuit layer and a packaging layer according to a stacked structure, the electrodes and the circuit layer are provided with tactile sensing arrays corresponding to the sensing units in position; the conductive shielding layer effectively solves the problem of misrecognition caused by electrode crosstalk and circuit interference in the triboelectric tactile sensor, and the tactile sensing array formed by arranging the sensing electrodes formed by semi-circle complementation and the whole-circle sensing electrodes is used for detecting and converting external physical stimulation into electric signals. And the coding sensing mechanism of the sensing unit is determined through the '0' and '1' coding combination. According to the invention, the three key performances of the triboelectric tactile sensor, namely the practical application reliability, the anti-interference stability and the wearing feasibility, are remarkably improved, and a better solution is provided for wearable electronic equipment.

Description

Technical Field

[0001] The present invention belongs to the technical field of flexible electronic tactile sensing, and relates to a triboelectric tactile sensor, and in particular to a coding-based low-error recognition triboelectric tactile sensor and a preparation method thereof. Background Art

[0002] As the largest organ in the human body, the skin's unique biological properties provide important insights into the development of electronic skin technology. Skin not only possesses exceptional flexibility, stretchability, and self-healing abilities, but is also a highly integrated sensory system capable of actively sensing and transmitting information from a variety of external stimuli, including touch, pressure, temperature, and humidity. Tactile sensing technology has made significant progress in recent years. By simulating the skin's tactile feedback mechanism, VR systems can achieve more natural force reproduction. Drawing on the skin's multimodal sensing properties, multifunctional tactile gloves have been developed that integrate temperature, vibration, and texture recognition. Skin-inspired flexible wearable HMIs have been widely used in physiological monitoring, motion detection, robotics, healthcare, and other fields.

[0003] Traditional tactile sensors are primarily based on capacitive, resistive, and optical sensing principles. These technologies suffer from common limitations such as complex structures, lack of flexibility, and the need for continuous external energy input. In contrast, triboelectric nanogenerators (TENGs), based on the triboelectric effect and electrostatic inductive coupling, exhibit unique advantages. TENGs can directly convert mechanical energy into high-amplitude electrical signals, enabling high-precision tactile recognition and pressure distribution measurement. However, current TENG sensor arrays face two key challenges: first, the conflict between multiplexing design and severe misidentification, primarily due to electrical signal interference between sensor nodes and internal circuitry; and second, the dilemma of wiring selection: independent channel connections simplify circuit design but complicate wiring, while XY crossbar arrays simplify wiring but exacerbate signal interference between rows and columns. These technical bottlenecks severely restrict the practical application of TENG sensor matrices in fields such as tactile sensing. Summary of the Invention

[0004] In response to the shortcomings of existing triboelectric tactile sensors, the present invention provides a low-error recognition triboelectric tactile sensor based on coding and a preparation method thereof. The triboelectric tactile sensor includes a conductive shielding layer, a triboelectric layer, an electrode and circuit layer, and an encapsulation layer. The conductive shielding layer effectively solves the misidentification problem caused by electrode crosstalk and circuit interference that are prevalent in triboelectric tactile sensors. It uses a tactile sensing array composed of complementary semicircular sensing electrodes and full-circle sensing electrodes to detect and convert external physical stimuli into electrical signals, and determines the coding sensing mechanism of the sensing unit through a combination of "0" and "1" coding. The sensor uses friction electrification and electrostatic induction effects to generate voltage, which effectively solves the shortcomings of traditional sensors in electrode crosstalk and circuit interference, the number of electrode channels, power supply, and adaptability to various complex environments. The present invention significantly improves the three key performances of triboelectric tactile sensors: practical application reliability, anti-interference stability, and wearable feasibility, providing a better solution for wearable electronic devices.

[0005] The purpose of the present invention is achieved through the following technical solutions:

[0006] A coding-based low-error recognition triboelectric tactile sensor includes, according to a stacked structure, a conductive shielding layer, a triboelectric layer, an electrode and circuit layer, and a packaging layer, wherein:

[0007] The conductive shielding layer is provided with a sensing unit and a grounding wire, wherein the sensing unit is n×n circular sensing patterns cut on the conductive shielding layer, where n≧3;

[0008] The electrode and circuit layer is provided with a tactile sensing array corresponding to the position of the sensing unit;

[0009] The tactile sensing array is an n×n array composed of sensing electrodes formed by complementary semicircles and sensing electrodes formed by full circles. The sensing electrodes formed by complementary semicircles and the sensing electrodes formed by full circles are connected by electrode wires to form different electrode patterns. The electrode patterns are connected to the input port of the microcontroller through electrode channels. The electrode channel that outputs high voltage is defined as "1", and the electrode channel that outputs low voltage is defined as "0". The touch position and sliding trajectory are determined according to the different "1" and "0" combinations output by different electrode channels.

[0010] A method for preparing the above-mentioned coding-based low-error recognition triboelectric tactile sensor comprises the following steps:

[0011] Step S1: Preparation of composite material:

[0012] The PDMS main agent and carbon black were added to n-hexane, ultrasonically dispersed, magnetically stirred, and a curing agent was added to form a composite material;

[0013] Step S2: Preparation of PDMS:

[0014] Pour the curing agent into the PDMS main agent, stir magnetically, and remove bubbles in a vacuum to form PDMS;

[0015] Step S3: Preparation of a low-error recognition triboelectric tactile sensor based on coding:

[0016] Step S3.1: Pour the composite material into a template, lead out a wire as a ground wire, and after vacuum degassing and heat curing, form a flexible conductive film. Laser cut out the sensing pattern to form a conductive shielding layer.

[0017] Step S3.2: Place the template on the conductive shielding layer, pour PDMS, and form a triboelectric layer after vacuum debubbling and heating and curing;

[0018] Step S3.3: Place the template on the triboelectric layer, pour the composite material into the acrylic template, connect four electrode wires, and after vacuum degassing and heat curing, form flexible electrodes and circuits. Remove the acrylic template to form the electrode and circuit layer.

[0019] Step S3.4: Place the template on the electrode and circuit layer, pour PDMS, and form an encapsulation layer after vacuum debubbling and heating and curing;

[0020] Step S3.5: peeling off the four layers solidified into one from the template, thereby completing the preparation of the coding-based low-error recognition triboelectric tactile sensor.

[0021] Compared with the existing technology, the present invention has the following advantages due to its unique coding sensing mechanism and working principle:

[0022] 1. The triboelectric tactile sensor of the present invention adopts triboelectric nanogenerator technology, which realizes self-powering through the charge transfer generated by touch, without the need for external power supply. The triboelectric nanogenerator can directly convert mechanical energy into high-amplitude electrical signals, realizing high-precision tactile recognition.

[0023] 2. The conductive shielding layer of the triboelectric tactile sensor of the present invention effectively solves the problem of misidentification caused by electrode crosstalk and circuit interference that are common in triboelectric tactile sensors, greatly improves the sensing fidelity and enhances the application stability of the triboelectric nanogenerator tactile sensing matrix.

[0024] 3. The triboelectric tactile sensor of the present invention uses an electrode array composed of sensing electrodes formed by complementary semicircles and sensing electrodes formed by full circles to detect and convert external physical stimuli into electrical signals, and determines the sensing position through the sensing mechanism of "0" and "1" coding combinations, which can greatly reduce the number of electrode wires. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1Schematic diagram of the overall structure of the low-error recognition triboelectric tactile sensor based on coding: 1-conductive shielding layer, 2-triboelectric layer, 3-electrode and circuit layer, 4-packaging layer;

[0026] Figure 2 Schematic diagram of the preparation process of the low-error recognition triboelectric tactile sensor based on coding;

[0027] Figure 3 Schematic diagram of interference shielding for low-error recognition triboelectric tactile sensor based on coding;

[0028] Figure 4 Schematic diagram of the encoding sensing mechanism of the low-error recognition triboelectric tactile sensor based on encoding;

[0029] Figure 5 A schematic diagram showing the application of a low-error recognition triboelectric tactile sensor based on coding;

[0030] Figure 6 Detailed electrode pattern diagram of the coding-based low-false-identification triboelectric tactile sensor;

[0031] Figure 7 Schematic diagram of a 3×3 different sensing array of a coding-based low-error recognition triboelectric tactile sensor. DETAILED DESCRIPTION

[0032] The technical solution of the present invention is further described below with reference to the accompanying drawings, but is not limited thereto. Any modification or equivalent replacement of the technical solution of the present invention that does not depart from the spirit and scope of the technical solution of the present invention should be included in the scope of protection of the present invention.

[0033] The present invention provides a low-error recognition triboelectric tactile sensor based on coding, such as Figure 1 As shown, taking a 3×3 array as an example, the triboelectric tactile sensor is stacked in the vertical direction with a conductive shielding layer 1, a triboelectric layer 2, an electrode and circuit layer 3, and a packaging layer 4, wherein:

[0034] The conductive shielding layer 1 is provided with a sensing unit and a grounding wire. The sensing unit is 9 circular sensing patterns cut on the conductive shielding layer 1.

[0035] The sensing unit is filled with a triboelectric layer 2;

[0036] The electrode and circuit layer 3 is provided with a tactile sensing array corresponding to the position of the sensing unit;

[0037] The tactile sensing array is a 3×3 array consisting of five semicircular complementary sensing electrodes and four full-circle sensing electrodes;

[0038] The sensing electrodes formed by the complementary semicircles and the sensing electrodes formed by the full circle are connected through electrode wires to form four electrode patterns;

[0039] Among the four electrode patterns, electrode pattern 1 is the same as electrode pattern 3, electrode pattern 2 is the same as electrode pattern 4, electrode pattern 1 and electrode pattern 3 are arranged symmetrically up and down, and electrode pattern 2 and electrode pattern 4 are arranged symmetrically left and right, electrode pattern 1 is connected to microcontroller input port 1 through electrode channel 1, electrode pattern 2 is connected to microcontroller input port 2 through electrode channel 2, electrode pattern 3 is connected to microcontroller input port 3 through electrode channel 3, and electrode pattern 4 is connected to microcontroller input port 4 through electrode channel 4. The electrode channel that outputs high voltage is defined as "1", and the electrode channel that outputs low voltage is defined as "0". The touch position and sliding trajectory are determined according to the different combinations of "1" and "0" output by the four electrode channels.

[0040] like Figure 6As shown, the electrode pattern 1 is composed of a full circle 1, a semicircle 1, a semicircle 2, and a semicircle 3. The full circle 1 is connected to the semicircle 1 through the electrode wire 1, is connected to the semicircle 2 through the electrode wire 2, and is connected to the semicircle 3 through the electrode wire 3. The angle between the electrode wire 1 and the electrode wire 2 is 180°, and the angle between the electrode wire 3 and the electrode wire 1 and the electrode wire 2 is 90°; the electrode pattern 3 is composed of a full circle 3, a semicircle 6, a semicircle 7, and a semicircle 8. The full circle 3 is connected to the semicircle 6 through the electrode wire 6, is connected to the semicircle 7 through the electrode wire 7, and is connected to the semicircle 8 through the electrode wire 8. The angle between the electrode wire 6 and the electrode wire 7 is 180°, and the angle between the electrode wire 8 and the electrode wire 6 and the electrode wire 7 is 90°; the The electrode pattern 2 is composed of a whole circle 2, a semicircle 4, and a semicircle 5. The whole circle 2 is connected to the semicircle 4 through the electrode wire 4, and is connected to the semicircle 5 through the electrode wire 5. The angle between the electrode wire 4 and the electrode wire 5 is 180°; the electrode pattern 4 is composed of a whole circle 4, a semicircle 9, and a semicircle 10. The whole circle 4 is connected to the semicircle 9 through the electrode wire 9, and is connected to the semicircle 10 through the electrode wire 10. The angle between the electrode wire 9 and the electrode wire 10 is 180°; the semicircle 1 and the semicircle 9 complement each other to form the sensing electrode 1, the semicircle 2 and the semicircle 4 complement each other to form the sensing electrode 2, the semicircle 5 and the semicircle 7 complement each other to form the sensing electrode 3, the semicircle 6 and the semicircle 10 complement each other to form the sensing electrode 4, and the semicircle 3 and the semicircle 8 complement each other to form the sensing electrode 5. When the user presses one of the nine sensor units, due to the triboelectric effect, the corresponding electrode channel will output a high voltage and be set to "1", while the other electrode channels will not output voltage because they are not pressed and are set to "0". The coding combination of "0" and "1" corresponds to different positions. By arranging the sensor electrodes (semicircle and full circle) and combining the output of the signal (coding of high and low voltage 10), the output of 1001, 1000, 1100, 0001, 1010, 0100, 0011, 0010, 0110 can be achieved, thereby realizing the positioning of the corresponding position. For example: when the user presses the sensor unit corresponding to the position of sensor electrode 1, electrode channel 1 and electrode channel 4 (corresponding to microcontroller input ports 1 and 4) will output a high voltage through the amplifier circuit, and assign the voltage state of microcontroller input ports 1 and 4 to Boolean variables 1 and 4. At this time, bool1=1, bool4=1, while electrode channel 2 and electrode channel 3 (corresponding to microcontroller input ports 2 and 3, assigning the voltage state of input ports 2 and 3 to Boolean variables 1 and 4) are not pressed and output a low voltage. At this time, bool2=0, bool3=0, and the program then executes the corresponding instructions to output the code 1001.Similarly, when the user presses the sensor unit corresponding to the whole circle 1, electrode channel 1 will output a high voltage through the amplifier circuit, and assign the voltage state of input port 1 to Boolean variable 1, at this time bool1 = 1; while electrode channel 2, electrode channel 3 and electrode channel 4 are not pressed, and output a low voltage, at this time bool2 = 0, bool3 = 0, bool4 = 0, and then the program executes the corresponding instructions and outputs the code 1000.

[0041] In the present invention, Figure 7 As shown, the 3×3 array can also have many other electrode arrangements.

[0042] In the present invention, the conductive shielding layer 1 is a conductive film. Preferably, the conductive shielding layer 1 is a composite material layer made of a PDMS main agent, a curing agent and conductive particles. The conductive particles are carbon black particles with an average particle size of 50 nm. The mass ratio of the PDMS main agent to the curing agent is 10:1, and the mass ratio of the PDMS main agent and the curing agent to the conductive particles is 13.4:1.

[0043] In the present invention, the triboelectric layer 2 is a PDMS cured layer made of a PDMS main agent and a curing agent, and the mass ratio of the PDMS main agent to the curing agent is 10: 1. The triboelectric layer 2 can also be other flexible negatively charged materials.

[0044] In the present invention, the electrode and circuit layer 3 is a flexible electrode and circuit. Preferably, the electrode and circuit layer 3 is a composite material layer made of a PDMS main agent, a curing agent and conductive particles. The conductive particles are carbon black particles with an average particle size of 50 nm. The mass ratio of the PDMS main agent to the curing agent is 10:1, and the mass ratio of the PDMS main agent and the curing agent to the conductive particles is 13.4:1.

[0045] In the present invention, the encapsulation layer 4 is a PDMS encapsulation layer made of a PDMS main agent and a curing agent, and the mass ratio of the PDMS main agent to the curing agent is 10: 1. The encapsulation layer 4 can also be other flexible encapsulation materials.

[0046] In the present invention, the conductive shielding layer 1 and the electrode and circuit layer 3 have a circular pattern design with corresponding sizes, wherein the circular size of the conductive shielding layer 1 is slightly larger than the sensing electrode and the full-circle sensing electrode formed by the complementary semicircles, and the sensing electrode formed by the complementary semicircles has a certain isolation gap in the middle. In addition to the circular pattern design, it can also be a symmetrical pattern such as a triangular pattern, a rectangular pattern, an elliptical pattern, a pentagonal pattern, etc., and the circular pattern design is preferred. When the electrode and the circuit layer crosstalk and mistakenly touch, the inflow and backflow of free electrons caused by the skin contact and separation process will be affected by the conductive shielding layer. The conductive shielding layer will shield the inflow and backflow of most free electrons, achieve a shielding effect, and reduce misidentification. Specifically manifested as: Figure 3As shown in the figure, when the skin accidentally touches the sensor circuit, the negative triboelectric charge on the conductive shielding layer tends to balance the positive triboelectric charge on the skin, disrupting the charge balance within the sensor. Free electrons flow from the conductive shielding layer's grounding conductor into the conductive shielding layer. When the skin separates from the sensor circuit, the negative electric field on the surface of the conductive shielding layer forces the excess electrons back from the conductive shielding layer through the grounding wire and into the ground. Since the entire process involves only a charge change between the skin and the conductive shielding layer, it has little impact on the electrodes connected to the electrode leads, thus eliminating the problem of false recognition caused by circuit interference.

[0047] The sensing electrodes, formed by two complementary semicircular electrodes, undergo simultaneous electrical signal changes, so crosstalk between adjacent sensing units caused by electrostatic induction does not affect sensing accuracy. Therefore, only the full-circular sensing electrodes experience crosstalk. Due to the conductive shielding layer, most of the electrons generated by electrostatic induction flow in and out through it. The full-circular sensing electrodes are spaced a certain distance from the semicircular sensing electrodes, and the circuitry constructed from composite materials has impedance, ultimately minimizing the impact of crosstalk.

[0048] like Figure 4 As shown, the four electrode patterns of the tactile sensor are composed of 9 sensing units through the electrode array composed of sensing electrodes formed by complementary semicircles and full-circle sensing electrodes. Touching different sensing units will cause the corresponding electrode channels to output higher voltages, while other electrode channels are not affected and output lower voltages. High voltage is defined as "1" and low voltage is defined as "0". The four electrode channels output different combinations of "1" and "0", and the touch position and sliding trajectory are determined based on these combinations.

[0049] The application of low-error recognition triboelectric tactile sensor based on coding is shown as follows Figure 5 As shown, the 9 sensing units are pre-programmed as Q, W, E, R and numbers 1 to 5 in sequence.

[0050] In the present invention, the tactile sensing array can also be a 4×4 array or a 5×5 array. A 4×4 array requires one additional electrode channel, a 5×5 array requires two additional electrode channels, and so on. Based on these arrays, corresponding full-circle and semi-circle electrode arrangements are designed to form a corresponding number of electrode patterns. For an n×n array, appropriate electrode channels can be added based on specific needs. As the array resolution increases, three or four sectors may be required to form a sensing unit. Because of the shielding layer, the electrode conductors can be arranged in any desired pattern as long as they do not cross.

[0051] The present invention also provides a method for preparing the above-mentioned triboelectric tactile sensor, such as Figure 2 As shown, the method includes the following steps:

[0052] Step S1: Preparation of composite material:

[0053] Add the PDMS main agent and carbon black to an appropriate amount of n-hexane, disperse them ultrasonically, stir them magnetically, and add a curing agent to form a composite material. The specific steps are as follows:

[0054] Step S1.1: Pour 0.5 g of carbon black and 6.03 g of PDMS main agent into 30 ml of n-hexane;

[0055] Step S1.2, ultrasonic dispersion at 25°C and 65W ultrasonic power for 20 minutes;

[0056] Step S1.3, heating at 90°C and stirring with magnetic stirring at 800 rpm;

[0057] Step S1.4: After the n-hexane is completely evaporated, the mixture is cooled to room temperature, 0.67 g of curing agent is added, and magnetic stirring is performed for 5 minutes.

[0058] Step S2: Preparation of PDMS:

[0059] Step S2.1: Pour 0.8 g of curing agent into 8 g of PDMS base;

[0060] Step S2.2, stirring under magnetic stirring at 600 rpm for 5 minutes;

[0061] Step S2.3: Vacuum remove air bubbles for 40 minutes.

[0062] Step S3: Preparation of a low-error recognition triboelectric tactile sensor based on coding:

[0063] Step S3.1: Pour the composite material into an acrylic template, lead out a wire as a ground wire, remove air bubbles in a vacuum, and then heat-cure at 60°C for 4 hours to form a flexible conductive film. Laser-cut nine circular sensing patterns to form a conductive shielding layer.

[0064] Step S3.2: Place the acrylic template on the conductive shielding layer, pour PDMS, remove bubbles in a vacuum, and then heat and cure at 60°C for 4 hours to form a triboelectric layer.

[0065] Step S3.3: Place an acrylic template on the triboelectric layer, pour the composite material into the acrylic template, connect four electrode wires, remove bubbles in a vacuum, and heat-cure at 60°C for 4 hours to form flexible electrodes and circuits. Remove the acrylic template to form the electrode and circuit layer.

[0066] Step S3.4: Place the acrylic template on the electrode and circuit layer, pour PDMS, remove bubbles in a vacuum, and then heat and cure at 60°C for 4 hours to form an encapsulation layer;

[0067] Step S3.5: peeling off the four layers solidified together from the acrylic template to complete the preparation of the coding-based low-error recognition triboelectric tactile sensor.

[0068] The advantages of the present invention compared with the prior art include:

[0069] 1. This invention achieves self-powering through the coupling mechanism of triboelectric charging and electrostatic induction, eliminating the need for an external power source. This technology reduces the device's dependence on power, improves the sensor's adaptability and flexibility, and demonstrates unique advantages in specialized applications such as medical applications, disaster relief, and aerospace.

[0070] 2. Compared with the sensing unit electrode wire pattern from row (X) + column (Y) to row (X) × column (Y), the present invention uses an electrode array composed of complementary semicircular sensing electrodes and full-circle sensing electrodes and a coding combination of "0" and "1" to determine the coding sensing mechanism of the sensing unit, which can greatly reduce the number of electrode channels.

[0071] 3. The conductive shielding layer of the present invention effectively solves the problem of misidentification caused by electrode crosstalk and circuit interference that is common in triboelectric tactile sensors, greatly improves the sensing fidelity and enhances the application stability of the triboelectric nanogenerator sensing matrix.

[0072] 4. Applications of this invention include, but are not limited to, intelligent control for human-computer interaction, and also have broad application prospects in fields such as healthcare, disaster relief, and flexible control. In particular, in scenarios requiring flexible wearable devices and high environmental adaptability, the tactile sensor of this invention can provide stable and accurate tactile feedback, enhancing the operational accuracy and safety of the device.

Claims

1. A low-error recognition triboelectric tactile sensor based on coding, characterized in that The sensor comprises a conductive shielding layer, a triboelectric layer, an electrode and circuit layer, and a packaging layer in sequence according to a stacked structure, wherein: The conductive shielding layer is provided with a sensing unit and a grounding wire, wherein the sensing unit is n×n circular sensing patterns cut on the conductive shielding layer, where n≧3; The electrode and circuit layer is provided with a tactile sensing array corresponding to the position of the sensing unit; The tactile sensing array is an n×n array composed of sensing electrodes formed by complementary semicircles and sensing electrodes formed by full circles. The sensing electrodes formed by complementary semicircles and the sensing electrodes formed by full circles are connected by electrode wires to form different electrode patterns. The electrode patterns are connected to the input port of the microcontroller through electrode channels. The electrode channel that outputs high voltage is defined as "1" and the electrode channel that outputs low voltage is defined as "0". The touch position and sliding trajectory are determined based on the different "1" and "0" combinations output by different electrode channels.

2. The low-error recognition triboelectric tactile sensor based on coding according to claim 1 is characterized in that The conductive shielding layer is a composite material layer made of a PDMS main agent, a curing agent and conductive particles. The conductive particles are carbon black particles with an average particle size of 50 nm. The mass ratio of the PDMS main agent to the curing agent is 10:1, and the mass ratio of the PDMS main agent and the curing agent to the conductive particles is 13.4:

1.

3. The low-error recognition triboelectric tactile sensor based on coding according to claim 1 is characterized in that The triboelectric layer is a PDMS cured layer made of a PDMS main agent and a curing agent, and the mass ratio of the PDMS main agent to the curing agent is 10:

1.

4. The low-error recognition triboelectric tactile sensor based on coding according to claim 1 is characterized in that The electrode and circuit layer is a composite material layer made of a PDMS main agent, a curing agent and conductive particles. The conductive particles are carbon black particles with an average particle size of 50 nm. The mass ratio of the PDMS main agent to the curing agent is 10:1, and the mass ratio of the PDMS main agent and the curing agent to the conductive particles is 13.4:

1.

5. The low-error recognition triboelectric tactile sensor based on coding according to claim 1 is characterized in that The encapsulation layer is a PDMS encapsulation layer made of a PDMS main agent and a curing agent, and the mass ratio of the PDMS main agent to the curing agent is 10:

1.

6. The low-error recognition triboelectric tactile sensor based on coding according to claim 1 is characterized in that The sensing unit is 9 circular sensing patterns cut on the conductive shielding layer, and the tactile sensing array is a 3×3 array consisting of sensing electrodes composed of five complementary semicircles and four full-circle sensing electrodes; the sensing electrodes composed of complementary semicircles and the sensing electrodes composed of full circles are connected by electrode wires to form four electrode patterns; among the four electrode patterns, electrode pattern 1 and electrode pattern 3 are identical, electrode pattern 2 and electrode pattern 4 are identical, electrode pattern 1 and electrode pattern 3 are arranged symmetrically in the upper and lower parts, and electrode pattern 2 and electrode pattern 4 are arranged symmetrically in the left and right parts. Electrode pattern 1 is connected to microcontroller input port 1 through electrode channel 1, electrode pattern 2 is connected to microcontroller input port 2 through electrode channel 2, electrode pattern 3 is connected to microcontroller input port 3 through electrode channel 3, and electrode pattern 4 is connected to microcontroller input port 4 through electrode channel 4. The electrode channel that outputs high voltage is defined as "1", and the electrode channel that outputs low voltage is defined as "0". The touch position and sliding trajectory are determined based on the different combinations of "1" and "0" output by the four electrode channels.

7. The low-error recognition triboelectric tactile sensor based on coding according to claim 6 is characterized in that The electrode pattern 1 is composed of a full circle 1, a semicircle 1, a semicircle 2, and a semicircle 3. The full circle 1 is connected to the semicircle 1 through the electrode wire 1, is connected to the semicircle 2 through the electrode wire 2, and is connected to the semicircle 3 through the electrode wire 3. The angle between the electrode wire 1 and the electrode wire 2 is 180 degrees, and the angle between the electrode wire 3 and the electrode wire 1 and the electrode wire 2 is 90 degrees; the electrode pattern 3 is composed of a full circle 3, a semicircle 6, a semicircle 7, and a semicircle 8. The full circle 3 is connected to the semicircle 6 through the electrode wire 6, is connected to the semicircle 7 through the electrode wire 7, and is connected to the semicircle 8 through the electrode wire 8. The angle between the electrode wire 6 and the electrode wire 7 is 180 degrees, and the angle between the electrode wire 8 and the electrode wire 6 and the electrode wire 7 is 90 degrees; the electrode Pattern 2 is composed of a whole circle 2, a semicircle 4, and a semicircle 5. The whole circle 2 is connected to the semicircle 4 through the electrode wire 4, and is connected to the semicircle 5 through the electrode wire 5. The angle between the electrode wire 4 and the electrode wire 5 is 180°; the electrode pattern 4 is composed of a whole circle 4, a semicircle 9, and a semicircle 10. The whole circle 4 is connected to the semicircle 9 through the electrode wire 9, and is connected to the semicircle 10 through the electrode wire 10. The angle between the electrode wire 9 and the electrode wire 10 is 180°; the semicircle 1 and the semicircle 9 complement each other to form the sensing electrode 1, the semicircle 2 and the semicircle 4 complement each other to form the sensing electrode 2, the semicircle 5 and the semicircle 7 complement each other to form the sensing electrode 3, the semicircle 6 and the semicircle 10 complement each other to form the sensing electrode 4, and the semicircle 3 and the semicircle 8 complement each other to form the sensing electrode 5.

8. The coding-based low-error recognition triboelectric tactile sensor according to claim 1, 6 or 7, characterized in that The conductive shielding layer, the electrode and the circuit layer have a circular pattern design with corresponding sizes, wherein the circular size of the conductive shielding layer is larger than the sensing electrodes formed by the complementary semicircles and the full-circle sensing electrodes, and there is a certain isolation gap in the middle of the sensing electrodes formed by the complementary semicircles.

9. The low-error recognition triboelectric tactile sensor based on coding according to claim 8, characterized in that The circular pattern is replaced by a triangular pattern, a rectangular pattern, an elliptical pattern or a pentagonal pattern.

10. A method for preparing a coding-based low-error recognition triboelectric tactile sensor according to any one of claims 1 to 9, characterized in that The method comprises the following steps: Step S1: Preparation of composite material: The PDMS main agent and carbon black were added to n-hexane, ultrasonically dispersed, magnetically stirred, and a curing agent was added to form a composite material; Step S2: Preparation of PDMS: Pour the curing agent into the PDMS main agent, stir magnetically, and remove bubbles in a vacuum to form PDMS; Step S3: Preparation of a low-error recognition triboelectric tactile sensor based on coding: Step S3.1: Pour the composite material into a template, lead out a wire as a ground wire, and after vacuum degassing and heat curing, form a flexible conductive film. Laser cut out the sensing pattern to form a conductive shielding layer. Step S3.2: Place the template on the conductive shielding layer, pour PDMS, and form a triboelectric layer after vacuum debubbling and heating and curing; Step S3.3: Place the template on the triboelectric layer, pour the composite material into the acrylic template, connect four electrode wires, and after vacuum degassing and heat curing, form flexible electrodes and circuits. Remove the acrylic template to form the electrode and circuit layer. Step S3.4: Place the template on the electrode and circuit layer, pour PDMS, and form an encapsulation layer after vacuum debubbling and heating and curing; Step S3.5: peeling off the four layers solidified into one from the template, thereby completing the preparation of the coding-based low-error recognition triboelectric tactile sensor.

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