Tactile sensor and method of manufacturing the same

Abstract

The embodiment of the present application provides a tactile sensor and a method for manufacturing the same, which includes a thin film transistor and a pressure sensing component conductively connected to the thin film transistor; the pressure sensing component includes a first elastomer, a second elastomer and conductive particles located between the first elastomer and the second elastomer; the pressure sensing component senses a pressure signal through the first elastomer and the second elastomer, and converts the sensed pressure signal into an electrical signal; the thin film transistor includes a source, a drain and a gate, and the pressure sensing component transmits the electrical signal to the gate of the thin film transistor through the interface where the conductive particles are located; the source and drain of the thin film transistor are signal output terminals of the tactile sensor; in this way, the sensitivity of pressure sensing is guaranteed, and the calculation and storage of the sensing signal can be realized through the characteristics of the thin film transistor, thereby providing a technical basis for forming a multifunctional integrated tactile sensor.

Description

Technical Field

[0001] The present application relates to electronic devices, and in particular to a tactile sensor and a method for manufacturing the same. Background Art

[0002] In recent years, artificial intelligence has developed rapidly, and modern society has developed towards an intelligent information society. Intelligent programs such as AlphaGo have realized artificial intelligence in software. In terms of hardware, neuromorphic electronics inspired by the working mode of the human brain has developed rapidly. The two-terminal memristor and three-terminal transistor that can imitate the synaptic learning behavior in the human brain have realized the integration of information calculation and storage in hardware, proposed a new generation of computing paradigm, and promoted the development of artificial neural networks and neuromorphic engineering. Many sensors such as pressure sensors such as electronic skin have realized the detection of stimulus signals, imitating the function of human skin to receive stimuli, and have been widely used in medical testing, sports health testing, and intelligent robotics technology.

[0003] The human body has a multifunctional perception system. A complete sensory activity requires the coordinated participation of the human body's receptors, afferent nerves, and nerve centers. For example, triggering touch requires the human skin to receive pressure signals. After the pressure signal is converted into an electrical signal, it is transmitted to the nerve center by the afferent nerve. After being processed by the nerve center, tactile perception is formed.

[0004] With the gradual development of neuromorphic electronic devices, the requirements for artificial bionic tactile sensors are getting higher and higher. How to improve the accuracy and sensitivity of sensing, increase the computing and storage functions of tactile sensors, and realize multifunctional integrated electronic devices or systems that integrate sensing, computing, and storage has become the focus of research in this field. Summary of the invention

[0005] In view of this, embodiments of the present application provide a tactile sensor and a method for manufacturing the same in order to solve at least one problem existing in the background technology.

[0006] The embodiment of the present application provides a tactile sensor, comprising: a thin film transistor, and a pressure sensing component conductively connected to the thin film transistor; wherein:

[0007] The pressure sensing component comprises a first elastic body, a second elastic body and conductive particles located between the first elastic body and the second elastic body; the pressure sensing component senses a pressure signal through the first elastic body and the second elastic body, and converts the sensed pressure signal into an electrical signal;

[0008] The thin film transistor includes a source, a drain and a gate. The pressure sensing component transmits the electrical signal to the gate of the thin film transistor through the interface where the conductive particles are located. The source and drain of the thin film transistor are signal output ends of the tactile sensor.

[0009] In an optional embodiment, the number of pressure sensing components conductively connected to one thin film transistor is more than two, and the more than two pressure sensing components are electrically insulated from each other.

[0010] In an optional embodiment, it further includes a wire;

[0011] One end of the wire is connected to the interface where the conductive particles are located, and the other end of the wire is connected to the gate to transmit the electrical signal.

[0012] In an optional embodiment, the first elastomer has a first concave-convex surface, the second elastomer has a second concave-convex surface, the first concave-convex surface is arranged toward the second concave-convex surface; and the conductive particles are distributed on the first concave-convex surface and the second concave-convex surface.

[0013] In an optional embodiment, the first concave-convex surface and / or the second concave-convex surface is formed by transferring from a mold having a microstructure.

[0014] In an optional embodiment, the material of the first elastomer and / or the second elastomer includes polydimethylsiloxane.

[0015] In an optional embodiment, the material of the conductive particles includes indium tin oxide, gold, silver, or a combination thereof.

[0016] In an optional embodiment, the thin film transistor further includes a gate dielectric layer, and the material of the gate dielectric layer includes a solid electrolyte having ion conductive properties.

[0017] The present application also provides a method for manufacturing a tactile sensor, the method comprising:

[0018] forming a first elastomer and a second elastomer, and forming conductive particles on surfaces of the first elastomer and the second elastomer;

[0019] The first elastic body and the second elastic body are packaged together with the sides on which the conductive particles are formed facing each other to form a pressure sensing component; the pressure sensing component senses a pressure signal through the first elastic body and the second elastic body, and converts the sensed pressure signal into an electrical signal;

[0020] forming a thin film transistor, wherein the thin film transistor comprises a source electrode, a drain electrode and a gate electrode;

[0021] The interface where the conductive particles in the pressure sensing component are located is conductively connected to the gate of the thin film transistor; the source and drain of the thin film transistor are conductively led out to form a signal output end of the touch sensor.

[0022] In an optional embodiment, the forming of the pressure sensing component includes: forming two or more independent pressure sensing components through the same steps;

[0023] The step of conductively connecting the interface where the conductive particles in the pressure sensing component are located to the gate of the thin film transistor comprises: conductively connecting two or more pressure sensing components to the gate of a thin film transistor respectively.

[0024] The above-mentioned tactile sensor and its manufacturing method include a thin film transistor and a pressure sensing component conductively connected to the thin film transistor; the pressure sensing component includes a first elastomer, a second elastomer and conductive particles located between the first elastomer and the second elastomer; the pressure sensing component senses the pressure signal through the first elastomer and the second elastomer, and converts the sensed pressure signal into an electrical signal; the thin film transistor includes a source, a drain and a gate, and the pressure sensing component transmits the electrical signal to the gate of the thin film transistor through the interface where the conductive particles are located; the source and drain of the thin film transistor are the signal output ends of the tactile sensor; in this way, the pressure sensing component that can accurately sense the pressure signal is electrically connected to the thin film transistor, which not only ensures the sensitivity of pressure sensing, but also realizes the calculation and storage of the sensing signal through the characteristics of the thin film transistor, thereby providing a technical basis for forming a multifunctional integrated tactile sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0026] Figure 1 This is a schematic diagram of the structure of a tactile sensor in one embodiment of the present application;

[0027] Figure 2 This is a schematic diagram of the structure of a tactile sensor in another embodiment of the present application;

[0028] Figure 3 A schematic diagram of a process for manufacturing a tactile sensor according to an embodiment of the present application;

[0029] Figures 4a to 4d They are respectively the channel current response curves of the tactile sensor prepared in the specific examples of the present application under different test conditions;

[0030] Figure 5 This is the Braille recognition test result of the tactile sensor prepared in the specific example of this application. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is further described in detail below in conjunction with the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. Based on the embodiments provided in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application. In addition, it can also be understood that although the efforts made in this development process may be complex and lengthy, for ordinary technicians in the field related to the contents disclosed in the present application, some changes such as design, manufacturing or production based on the technical contents disclosed in the present application are only conventional technical means, and should not be understood as insufficient contents disclosed in the present application.

[0032] Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those of ordinary skill in the art that the embodiments described in this application may be combined with other embodiments without conflict.

[0033] Unless otherwise defined, the technical terms or scientific terms involved in this application should be understood by people with ordinary skills in the technical field to which this application belongs. The words "one", "a", "a", "the" and the like involved in this application do not indicate a quantitative limitation, and may represent the singular or plural. The terms "include", "comprise", "have" and any of their variations involved in this application are intended to cover non-exclusive inclusions; for example, a process, method, system, product or device that includes a series of steps or modules (units) is not limited to the listed steps or units, but may also include steps or units that are not listed, or may also include other steps or units inherent to these processes, methods, products or devices. The words "connect", "connected", "coupled" and the like involved in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The "multiple" involved in this application refers to greater than or equal to two. "And / or" describes the association relationship of associated objects, indicating that there can be three relationships, for example, "A and / or B" can represent: A exists alone, A and B exist at the same time, and B exists alone. The terms "first", "second", "third" and the like involved in the present application are merely used to distinguish similar objects and do not represent a specific ordering of the objects.

[0034] First, please refer to Figure 1 . The embodiment of the present application provides a tactile sensor, comprising: a thin film transistor 200, and a pressure sensing component 100 conductively connected to the thin film transistor 200. The pressure sensing component 100 can be used as an electronic skin for sensing external pressure signals and converting the sensed pressure signals into electrical signals; the electrical signals are transmitted to the gate of the thin film transistor 200, and after the gate is stimulated, a regulating effect is produced on the channel, thereby realizing tactile perception by detecting the electrical signals flowing between the source and drain of the thin film transistor 200.

[0035] For details, please continue to refer to Figure 1 The pressure sensing component 100 includes a first elastomer 110, a second elastomer 120, and conductive particles 130 located between the first elastomer 110 and the second elastomer 120; the pressure sensing component 100 senses a pressure signal through the first elastomer 110 and the second elastomer 120, and converts the sensed pressure signal into an electrical signal.

[0036] Here, the first elastomer and / or the second elastomer may be a polymer elastomer, and its material may include polydimethylsiloxane (PDMS). In a specific application, the first elastomer and / or the second elastomer may be generated by using a prepolymer and a curing agent as precursors; wherein the prepolymer and the curing agent are configured into a polydimethylsiloxane solution in a mass ratio of, for example, 10:1 to 5:1, and after stirring and curing treatment, the first elastomer and / or the second elastomer made of polydimethylsiloxane is formed.

[0037] In addition, the material of the first elastomer and / or the second elastomer may further include polyurethane.

[0038] Please continue to refer to Figure 1 The first elastomer 110 has a first concavo-convex surface, the second elastomer 120 has a second concavo-convex surface, the first concavo-convex surface is arranged toward the second concavo-convex surface; the conductive particles 130 are distributed on the first concavo-convex surface and the second concavo-convex surface.

[0039] The first elastic body 110 includes, for example, a first microstructure 111, and the first microstructure 111 forms the first concavo-convex surface on the outer surface; similarly, the second elastic body 120 includes, for example, a second microstructure 121, and the second concavo-convex surface is formed on the outer surface. Conductive particles 130 are distributed on both the first concavo-convex surface and the second concavo-convex surface.

[0040] In an optional embodiment, the first concavoconvex surface and / or the second concavoconvex surface is formed by transfer from a mold having a microstructure. In a specific preparation, a mold having a microstructure is first provided, and then a configured elastomer material solution is poured on the surface of the mold having the microstructure and solidified. Here, the elastomer material solution is, for example, a solution of the aforementioned configured polydimethylsiloxane; the cured elastomer material is peeled off from the mold to obtain an elastomer having a microstructure. The elastomer can be used as the first elastomer and / or the second elastomer.

[0041] The mold with microstructure is, for example, a textured silicon wafer with a pyramid structure on the surface. The textured silicon wafer with pyramid structure can be obtained by performing a texture treatment on a single crystal Si (c-Si) wafer with a thickness of 300 μm to 700 μm and (100) orientation for about 5 to 15 minutes at 70° C. to 80° C. using potassium hydroxide or sodium hydroxide solution. It should be understood that the present application is not limited thereto, and the mold with microstructure can also be any substrate with microstructure, such as a lotus leaf, sandpaper, etc.

[0042] In an optional embodiment, the material of the conductive particles includes indium tin oxide, gold, silver, or a combination thereof; specifically, for example, indium tin oxide and silver. The conductive particles can be formed into a first conductive particle layer and a second conductive particle layer on the first concave-convex surface and the second concave-convex surface, respectively, and the thickness of the first conductive particle layer and the second conductive particle layer is, for example, in the range of 50nm to 150nm. In a specific preparation, the conductive particles can be deposited on the first concave-convex surface and the second concave-convex surface by magnetron sputtering and / or electron beam evaporation.

[0043] The pressure sensing assembly may further include an adhesive tape, which is used to fix the first elastic body and the second elastic body together in a manner of sandwiching the conductive particles in between. The first concave-convex surface and the second concave-convex surface are arranged face to face, for example, with convex surfaces facing convex surfaces and concave surfaces facing concave surfaces.

[0044] The electrical signal generated by the pressure sensing component can be led out through a wire, which can be specifically achieved by placing one end of the wire on the conductive particles before fixing with the tape; so that when fixing with the tape, the wire is clamped between the first elastic body and the second elastic body. In order to improve the stability of the connection, the wire and the conductive particles can also be fixed by an adhesive.

[0045] Please continue to refer to Figure 1 The thin film transistor 200 includes a source 250, a drain 260 and a gate 220. The pressure sensing component 100 transmits the electrical signal to the gate 220 of the thin film transistor through the interface where the conductive particles are located; the source 250 and the drain 260 of the thin film transistor are the signal output ends of the tactile sensor.

[0046] Here, the thin film transistor is, for example, an oxide thin film transistor.

[0047] The thin film transistor 200 may further include a substrate 210 . The substrate 210 is, for example, an insulating substrate, and its material may specifically be plastic.

[0048] The gate 220 is located on the substrate 210. In some other embodiments, a conductive substrate may be directly used, and the conductive layer of the conductive substrate is used as the gate of the thin film transistor. The material of the gate may include indium tin oxide.

[0049] The thin film transistor 200 further includes a gate dielectric layer 230, and the material of the gate dielectric layer 230 includes a solid electrolyte having ion conductive properties. Here, the material of the gate dielectric layer may specifically include at least one of the following: chitosan, egg white, methyl cellulose or starch. Furthermore, egg white and / or starch may be selected to form the gate dielectric layer, and egg white and starch have the advantages of being easy to obtain, low in cost and degradable.

[0050] It can be understood that the memory function of the tactile sensor for the pressure signal can be effectively realized by utilizing the relaxation effect of protons in the solid electrolyte with ionic conductivity.

[0051] The source and drain of the thin film transistor may be located on the gate dielectric layer and isolated from the gate by the gate dielectric layer. The material of the source and drain, for example, includes at least one of the following: indium tin oxide, indium tungsten oxide, indium zinc oxide.

[0052] Please continue to refer to Figure 1 The thin film transistor 200 further includes a channel layer 240. The channel layer 240 is located on the gate dielectric layer 230 and between the source 250 and the drain 260. The channel layer 240 is a semiconductor channel, and its material includes, for example, at least one of the following: indium tin oxide, indium tungsten oxide, and indium zinc oxide. The channel layer 240 is deposited on the surface of the gate dielectric layer 230 by sputtering technology. The thickness of the channel layer 240 ranges from 7nm to 70nm.

[0053] The wire 300 has one end connected to the interface where the conductive particles 130 are located, and the other end connected to the gate 220, so as to transmit an electrical signal from the pressure sensor component 100 to the thin film transistor 200. In practical applications, the wire 300 is, for example, a copper wire.

[0054] Figure 2 FIG. 1 is a schematic diagram of the structure of a touch sensor in another embodiment of the present application. As shown in the figure, in this embodiment, the number of pressure sensing components 100 conductively connected to a thin film transistor 200 is more than two ( Figure 2 In the figure, two are used as an example, and the two or more pressure sensing components 100 are electrically insulated from each other. In this way, the pressure sensing components can be placed in multiple different positions to perform multi-terminal pressure regulation.

[0055] Since the pressure sensing components are electrically connected to the thin film transistor in the embodiment of the present application, the connection point between the two occupies a very small area on the thin film transistor, so a large number of pressure sensing components can be arranged and connected to the thin film transistor together. For example, the number of pressure sensing components conductively connected to a thin film transistor is more than fifty. In practical applications, the gate of the thin film transistor can be connected to up to 1000 pressure sensing components, thereby meeting the multi-terminal control requirements of tactile sensing.

[0056] In a specific application, a constant source-drain voltage may be applied between the source and the drain of the thin film transistor, and the range of the source-drain voltage is, for example, 0.5V to 2V.

[0057] It can be understood that due to the good pressure sensing sensitivity and the ability to calculate and store sensing signals, the tactile sensor provided in the embodiment of the present application can be used as an artificial tactile sensing neuron, and thus applied to the field of human-computer interaction and electronic devices. In human-computer interaction technology, patterned pressure signals can also be transmitted as a carrier of information. Especially in the application of Braille recognition, since Braille is a special code, the blind can identify the specific meaning of Braille by touching the raised dots and sensing the pressure stimulation from the fingers, so the requirements for pressure sensing are higher. In general sensor devices, recognizing Braille codes requires multiple devices to detect at the same time, and the circuit is complex. The tactile sensor provided in the embodiment of the present application has a simple process, low cost, and simple circuit, which is of great significance to intelligent robot technology and human-computer interaction technology.

[0058] The embodiment of the present application also provides a method for manufacturing a tactile sensor. Figure 3 The flowchart of the manufacturing method of the tactile sensor provided in the embodiment of the present application is as shown in the figure, and the method includes:

[0059] S01, forming a first elastomer and a second elastomer, and forming conductive particles on surfaces of the first elastomer and the second elastomer;

[0060] S02, encapsulating the first elastic body and the second elastic body together with the sides having the conductive particles facing each other to form a pressure sensing component; the pressure sensing component senses a pressure signal through the first elastic body and the second elastic body, and converts the sensed pressure signal into an electrical signal;

[0061] S03, forming a thin film transistor, wherein the thin film transistor includes a source electrode, a drain electrode and a gate electrode;

[0062] S04, conductively connecting the interface where the conductive particles in the pressure sensing component are located to the gate of the thin film transistor; conductively leading out the source and drain of the thin film transistor to form a signal output end of the tactile sensor.

[0063] Here, the first elastomer and / or the second elastomer may be a polymer elastomer, and its material may include polydimethylsiloxane (PDMS), for example. In the specific preparation, the first elastomer and / or the second elastomer may be generated by using a prepolymer and a curing agent as precursors; wherein the prepolymer and the curing agent are configured into a polydimethylsiloxane solution, for example, in a mass ratio of 10:1 to 5:1, and after stirring and curing treatment, the first elastomer and / or the second elastomer made of polydimethylsiloxane is formed.

[0064] In addition, the material of the first elastomer and / or the second elastomer may further include polyurethane.

[0065] In a specific embodiment, the steps of forming the first elastomer and / or forming the second elastomer include: providing a mold having a microstructure; preparing an elastomer material solution; pouring the prepared elastomer material solution on the surface of the mold having the microstructure and curing it; peeling the cured elastomer material from the mold to obtain the first elastomer and / or the second elastomer. Here, curing can be specifically performed by heating curing, and the conditions for heating curing are, for example, heating curing at 70°C to 100°C for 1.5 to 2 hours.

[0066] Among them, the mold with microstructure is, for example, a textured silicon wafer with a pyramid structure on the surface. The steps for forming the textured silicon wafer with a pyramid structure may specifically include: at 70°C to 80°C, a single crystal Si (c-Si) wafer with a thickness of 300μm to 700μm and an orientation of (100) is textured for 5 to 15 minutes using potassium hydroxide or sodium hydroxide solution, thereby obtaining a textured silicon wafer with a pyramid structure. It should be understood that the present application is not limited to this, and the mold with microstructure can also be any substrate with a microstructure, such as a lotus leaf, sandpaper, etc.

[0067] Next, conductive particles are formed on the surface of the first elastomer and the second elastomer; specifically, the conductive particles may be formed on the surface of the first elastomer and the second elastomer by magnetron sputtering and / or electron beam evaporation. The conductive particles are made of indium tin oxide, gold, silver, or a combination thereof; specifically, indium tin oxide and silver. The conductive particles may be formed into a first conductive particle layer and a second conductive particle layer on the surface of the first elastomer and the second elastomer, respectively, and the thickness of the first conductive particle layer and the second conductive particle layer may range from 50 nm to 150 nm, for example.

[0068] In step S02, the first elastomer and the second elastomer are packaged together with the sides having the conductive particles facing each other to form a pressure sensing component, which may specifically include: arranging a wire on the surface of the first elastomer or the second elastomer having the conductive particles formed thereon; arranging the first elastomer and the second elastomer face to face with the conductive particles and the wire sandwiched in the middle, and fixing and packaging the two together with tape.

[0069] The preparation process of thin film transistors can be carried out in the following steps:

[0070] Providing a substrate, the substrate being, for example, an insulating substrate, and its material may specifically be plastic;

[0071] A gate is formed on a substrate; or, in some other embodiments, a conductive substrate is directly provided, and a conductive layer of the conductive substrate serves as a gate of the thin film transistor; the material of the gate may include indium tin oxide;

[0072] A gate dielectric layer is formed on the gate; here, the material of the gate dielectric layer includes a solid electrolyte with ion conductive properties, and specifically may include at least one of the following: chitosan, egg white, methyl cellulose or starch; in practical applications, for example, egg white and / or starch are selected to form the gate dielectric layer; the gate dielectric layer is formed by, for example, a spin coating method;

[0073] Next, a channel layer, a source electrode and a drain electrode are formed on the gate dielectric layer; specifically, the channel layer, the source electrode and the drain electrode can be deposited on the surface of the gate dielectric layer by sputtering technology; wherein the channel layer is a semiconductor channel, and its material, for example, includes at least one of the following: indium tin oxide, indium tungsten oxide, indium zinc oxide; the thickness of the channel layer ranges from 7nm to 70nm; the material of the source electrode and the drain electrode can also include at least one of the following: indium tin oxide, indium tungsten oxide, indium zinc oxide.

[0074] Next, step S04 is performed to conductively connect the interface where the conductive particles in the pressure sensing component are located to the gate of the thin film transistor; specifically, the interface where the conductive particles in the pressure sensing component are located can be connected to the gate of the thin film transistor through a wire.

[0075] The source and drain of the thin film transistor are conductively led out to form a signal output end of the touch sensor.

[0076] In an optional embodiment, the forming of the pressure sensing component includes: forming two or more independent pressure sensing components through the same steps;

[0077] The step of conductively connecting the interface where the conductive particles in the pressure sensing component are located to the gate of the thin film transistor comprises: conductively connecting two or more pressure sensing components to the gate of a thin film transistor respectively.

[0078] The tactile sensor and the manufacturing method thereof provided in the embodiment of the present application are further explained below with reference to a specific example.

[0079] The manufacturing method of the tactile sensor comprises the following steps:

[0080] Step 1: Prepare a polydimethylsiloxane solution using a prepolymer and a curing agent in a mass ratio of 10 to 1. After stirring for 20 minutes, evacuate the solution for 15 minutes to eliminate bubbles in the solution.

[0081] Step 2: Pour the solution after vacuum treatment in step 1 onto the surface of the prepared textured silicon wafer, and then place it in a 70°C oven for heating and curing. After 2 hours, tear off the cured polydimethylsiloxane from the textured silicon wafer, thereby replicating the surface microstructure of the polydimethylsiloxane.

[0082] Step 3: Using magnetron sputtering technology and electron beam evaporation technology, indium tin oxide and silver are deposited on the surface of the polydimethylsiloxane (ie, elastomer) obtained in step 2, and the film thickness is about 100 nanometers.

[0083] Step 4: Use tape to stick the copper wire to one end of the polydimethylsiloxane with conductive particles, and place the polydimethylsiloxane with both sides treated face to face, specifically, place the sides containing the conductive particles face to face, and finally package them to obtain a pressure sensing component.

[0084] Step 5: The plastic substrate containing the ITO gate is cleaned by cyclic ultrasonic cleaning of alcohol and deionized water.

[0085] Step 6: Blow dry the plastic substrate cleaned in step 5 with a nitrogen gun and place it with the side containing the indium tin oxide gate facing up.

[0086] Step 7: Prepare a chitosan film on the gate surface by spin coating as a gate dielectric layer.

[0087] Step 8: Using magnetron sputtering technology, a patterned indium tin oxide channel layer and source and drain electrodes are deposited on the chitosan film using a one-step mask process to obtain a thin film transistor.

[0088] Step 9: Use copper wire to connect the pressure sensing component obtained in step 4 to the gate of the thin film transistor obtained in step 8, thereby obtaining a tactile sensor. The tactile sensor can be used as an artificial tactile perception neuron, and the pressure sensing component is used as an electronic skin to sense external pressure signals, thereby triggering tactile perception activities.

[0089] Figures 4a to 4d They are respectively the channel current response curves of the tactile sensor prepared in the specific examples of the present application under different test conditions.

[0090] Specifically, first, at the biasing end of the pressure sensing component (see Figure 1 or Figure 2 A constant bias voltage of 1V is applied to the wire 300 connected to the pressure sensing component 100 but not to the thin film transistor 200 (i.e., the wire 300 on the left side of the figure), and a constant voltage of 0.5V is applied to the drain of the thin film transistor as the voltage for reading the channel current. Then, a pressure stimulus of 3.14 kPa is applied to the pressure sensing component for 0.2 seconds to obtain Figure 4a The channel current response curve shown is the curve of the channel current (or "excitatory postsynaptic current", expressed as "EPSC", unit μA) changing with time (Time, unit s). It can be found that Figure 4aThe channel current response curve shown is different from the response curve when the same test conditions are applied only to the pressure sensing component (without conductive connection to the thin film transistor). The curve displayed by the tactile sensor prepared in the specific example of the present application does not directly decrease to the initial current as the pressure disappears, but there is a relaxation phenomenon that slowly returns to the initial channel current. This indicates that the artificial tactile perception neurons manufactured have a memory effect on pressure stimulation and successfully imitate the human tactile function.

[0091] Similarly, different pressure magnitudes, different pressure durations, and different numbers of pressures are applied to the tactile sensor to detect changes in the channel current under different pressure conditions. Figure 4b It shows that under stimulation of different pressures (1.57Kpa, 3.14Kpa, 6.27Kpa, 7.84Kpa, 15.68Kpa), the channel current increases with the increase of pressure; Figure 4c It shows that under the conditions of the same pressure magnitude and different pressure durations (1.67s, 2.31s, 3.13s, 3.78s, 3.98s), the channel current increases with the increase in the duration of pressure; Figure 4d It shows that under the conditions of the same pressure magnitude and duration and different numbers of pressure stimuli (1#, 2#, 3#, 4#, 5#), the channel current increases with the increase of the number of pressures. The above test results show that the manufactured tactile sensor has the ability to perceive external pressure, can distinguish different pressure modes according to the response of the channel current, and has a certain memory effect on pressure. The manufactured tactile sensor successfully imitates the human tactile function.

[0092] Figure 5 This is the result of the Braille recognition test of the tactile sensor prepared in the specific example of the present application. Here, a tactile sensor having two pressure sensing components respectively conductively connected to the gate of a thin film transistor is prepared by the preparation method in the specific example.

[0093] First, a constant voltage of 1V and 2V is applied to the ends of the two pressure sensing components that are not connected to the gate of the thin film transistor, and a constant voltage of 0.5V is applied to the drain of the thin film transistor as the voltage for reading the channel current. A 3.14 kPa stimulus lasting 0.2 seconds is used as a raised dot in Braille. When recognizing Braille, each Braille character contains 6 dot signals. When a finger feels the stimulus, it means that the finger skin receives the raised dot signal and marks it as "1", otherwise, it is marked as "0". Braille is divided into 3 lines, each line contains two signals, so there are 4 types of recognizable labels in each line: "00", "10", "01", "11"; the two pressure sensing components are used as two fingers to recognize Braille, so there are four types of recognition response signals for each line of Braille. Figure 5 The response signal generated by the thin film transistor when recognizing each line of Braille is shown; when stimulated by "10", the relative response of the thin film transistor is 1 to 2 microamperes; when stimulated by "01", the relative response of the thin film transistor is 2 to 3.5 microamperes; when stimulated by "11", the relative response of the thin film transistor is 3.5 to 5 microamperes; when there is no stimulation, the channel current of the thin film transistor has no relative change. In the actual application scenario, the recognition of the "hello" Braille is taken as an example to illustrate. The relative channel current response corresponding to each line of each letter in "hello" is obtained through testing. The response current corresponding to each letter of "h", "e", "l" and "o" is marked differently. Therefore, any Braille letter can be identified based on the relative response of the channel current. Therefore, the artificial tactile perception neuron manufactured by the present invention has the function of recognizing Braille.

[0094] Taking the following factors into consideration: if only a general pressure sensor is used to detect the pressure signal, then only the pressure detection function can be realized, and there is no extended function such as memory and calculation of the pressure, which is difficult to be applied to neuromorphic electronic devices; and the neuromorphic synaptic devices currently used in this field can only imitate the learning and memory function of the synapse, and cannot realize sensing, calculation and storage at the same time; therefore, in view of the current technical status that neuromorphic electronic devices and pressure sensors cannot sense, calculate and store at the same time, a multifunctional tactile sensor integrating sensing, storage and computing is invented, which utilizes the piezoelectric conversion effect of the pressure sensing component and the potential of the expandable functions of the thin film transistor, such as the ion regulation effect in the gate dielectric layer, to realize the pressure perception function; and, by electrically connecting the pressure sensing component to the thin film transistor, a tactile sensor that connects multiple pressure sensing components to a thin film transistor can be provided, thereby realizing multi-terminal regulation of pressure and realizing pattern recognition of pressure.

[0095] In an embodiment where the material of the gate dielectric layer includes a solid electrolyte with ion conductive properties, the piezoelectric conversion properties of the pressure sensing component and the proton regulation properties of the ion conductor electrolyte are utilized to realize a pressure-driven device to imitate human tactile perception; the relaxation effect of protons in the electrolyte is utilized to realize the device's memory function of pressure, and by connecting multiple pressure sensing components to thin-film transistors, the response of the thin-film transistor channel current under different pressure modes can be distinguished to realize the recognition function of Braille.

[0096] Compared with the neuromorphic devices in the related art, the embodiments of the present application use a pressure sensing component combined with a thin film transistor (such as a synaptic device in the related art) to achieve the perception memory and pattern recognition of pressure stimulation, imitate human tactile perception activities, further optimize the function of a single sensor that can only detect pressure, and achieve the recognition of Braille. At the same time, the manufacturing process of the device is simple and the manufacturing cost is low. This artificial tactile perception neuron has good application prospects and important application potential in the field of intelligent robots and human-computer interaction technology.

[0097] The technical features of the above embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0098] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A tactile sensor, characterized in that: include: A thin film transistor, and a pressure sensing component conductively connected to the thin film transistor; wherein: The pressure sensing component comprises a first elastic body, a second elastic body and conductive particles located between the first elastic body and the second elastic body; the pressure sensing component senses a pressure signal through the first elastic body and the second elastic body, and converts the sensed pressure signal into an electrical signal; The thin film transistor comprises a source electrode, a drain electrode and a gate electrode, and the pressure sensing component transmits the electrical signal to the gate electrode of the thin film transistor through the interface where the conductive particles are located; the source electrode and the drain electrode of the thin film transistor are signal output terminals of the touch sensor; It also includes a wire; one end of the wire is connected to the interface where the conductive particles are located, and the other end of the wire is connected to the gate to transmit the electrical signal; A constant bias is applied to the bias application end of the pressure sensing component, a constant voltage is applied to the drain as the voltage for reading the channel current, and a pressure stimulus is applied to the pressure sensing component. The curve displayed by the tactile sensor does not directly decrease to the initial current as the pressure disappears, but there is a relaxation phenomenon in which the current slowly returns to the initial current of the channel.

2. The tactile sensor according to claim 1, characterized in that: The number of the pressure sensing components conductively connected to the thin film transistor is more than two, and the more than two pressure sensing components are electrically insulated from each other.

3. The tactile sensor according to claim 1, characterized in that: The first elastomer has a first concavo-convex surface, the second elastomer has a second concavo-convex surface, the first concavo-convex surface is arranged toward the second concavo-convex surface; the conductive particles are distributed on the first concavo-convex surface and the second concavo-convex surface.

4. The tactile sensor according to claim 3, characterized in that: The first concavo-convex surface and / or the second concavo-convex surface is formed by transfer from a mold having a microstructure.

5. The tactile sensor according to claim 1, characterized in that: The material of the first elastomer and / or the second elastomer includes polydimethylsiloxane.

6. The tactile sensor according to claim 1, characterized in that: The conductive particles are made of materials including indium tin oxide, gold, silver or a combination thereof.

7. The tactile sensor according to claim 1, characterized in that: The thin film transistor further comprises a gate dielectric layer, and the material of the gate dielectric layer comprises a solid electrolyte having ion conductive properties.

8. A method for manufacturing a tactile sensor, used for manufacturing the tactile sensor according to any one of claims 1 to 7, characterized in that: The method comprises: forming a first elastomer and a second elastomer, and forming conductive particles on surfaces of the first elastomer and the second elastomer; The first elastic body and the second elastic body are packaged together with the sides on which the conductive particles are formed facing each other, and a wire is arranged on the surface of the first elastic body or the second elastic body on which the conductive particles are formed to form a pressure sensing component; the pressure sensing component senses a pressure signal through the first elastic body and the second elastic body, and converts the sensed pressure signal into an electrical signal; forming a thin film transistor, wherein the thin film transistor comprises a source electrode, a drain electrode and a gate electrode; Conductively connecting the interface where the conductive particles in the pressure sensing component are located to the gate of the thin film transistor; conductively leading out the source and drain of the thin film transistor to form a signal output end of the touch sensor; A constant bias is applied to the bias application end of the pressure sensing component, a constant voltage is applied to the drain as the voltage for reading the channel current, and a pressure stimulus is applied to the pressure sensing component. The curve displayed by the tactile sensor does not directly decrease to the initial current as the pressure disappears, but there is a relaxation phenomenon in which the current slowly returns to the initial current of the channel.

9. The method for manufacturing a tactile sensor according to claim 8, characterized in that: The forming of the pressure sensing component comprises: forming two or more independent pressure sensing components through the same steps; Conductively connecting the interface where the conductive particles in the pressure sensing component are located with the gate of the thin film transistor comprises: conductively connecting two or more pressure sensing components with the gate of the thin film transistor respectively.

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