CN115507978A - Elasticity interdigital electrode sensor and wearable sensing equipment - Google Patents

Abstract

The invention belongs to the field of interdigital electrode sensors, and particularly relates to an elastic interdigital electrode sensor and wearable sensing equipment, wherein the elastic interdigital electrode sensor comprises an elastic interdigital electrode, the elastic interdigital electrode comprises a base film layer and a conducting layer coated on the surface of the base film layer, the base film layer is prepared by adopting an electrospinning elastomer through an electrostatic spinning process, the conducting layer is at least one interdigital electrode circuit formed on the base film layer by adopting liquid metal ink with a melting point lower than room temperature, and the liquid metal ink comprises liquid metal. The elastic interdigital electrode sensor provided by the invention has the advantages of good stretchability, high conductivity, suitability for large-area preparation, comfort and ventilation, recyclability, high stability and the like, and particularly unexpectedly has contact and non-contact dual-mode response and is excellent.

Description

An elastic interdigital electrode sensor and wearable sensing device

technical field

The invention belongs to the field of interdigital electrode sensors, in particular to an elastic interdigital electrode sensor and wearable sensing equipment.

Background technique

With the development trend of wearable and portable electronic products, flexible conductive materials have received extensive attention. In addition to the conductivity and elasticity of flexible conductive materials, electrical stability is also an extremely important consideration. Many practical applications such as stretchable electronic circuits, flexible batteries, and stretchable light source devices require conductive materials to have high electrical stability. To ensure that the device can still maintain good working performance during the deformation process, it is quite challenging for a highly stretchable elastic conductor to have high electrical stability at the same time. In addition, in addition to high electrical stability, it is also urgent to apply elastic conductors of porous films to elastic conductors in wearable electronic products. Such conductive materials are also required to have good air and vapor permeability. With the development of wearable products, future wearable electronic products also need stretchable conductive materials to meet the conditions of supporting multiple functions, small packaging volume, and high integration, so as to support better product performance.

Besides, efforts have been made to fabricate flexible sensors with contact and non-contact dual-modal responses. However, in most cases, it usually requires the integration of two or more types of electrical component materials or structures into a unified system, which greatly increases the complexity of production and operation. In this regard, several recent impressive studies have shown that based on capacitive (Nat Commun 2018, 9, 244) or triboelectric effects (Nano Energy 2022, 95, 107056; as disclosed in Chinese patent CN 110932592 B), It is feasible to design dual-mode sensors with miniaturization capabilities. However, the former suffers from a large trade-off in contact mode sensitivity (typically <1 MPa ^-1 ) for convincing non-contact performance; while the latter suffers from transient signals that are not suitable for stable continuous input Case. In addition to the functional characteristics of electronic products, the development of characteristics such as comfort, safety and environmental protection should also be considered to meet comprehensive needs. To date, flexible electronics fabricated with traditional materials and fabrication processes usually do not take the aforementioned properties into account. For example, reported advanced dual-mode sensors are mainly based on air-impermeable substrates (uncomfortable) and non-recyclable materials, while the fabrication process often requires expensive equipment, complicated procedures, high-standard operating environments, and specific material properties. Clearly, creating flexible human-machine interfaces that simultaneously possess multiple sensing capabilities, wearability, sensitive responsiveness, accurate detection, and convenient recycling remains a major challenge.

Contents of the invention

The object of the present invention is to provide an elastic interdigital electrode sensor and a wearable sensor device in order to overcome the shortcomings and deficiencies of the prior art.

The technical scheme adopted by the present invention is as follows: an elastic interdigital electrode sensor, which includes an elastic conductor composite film, the elastic conductor composite film includes a base film layer and a conductive layer coated on the surface of the base film layer, the base film The layer is prepared and formed by electrospinning elastomer through electrospinning process, and the conductive layer is at least one interdigitated electrode circuit formed on the base film layer by using liquid metal ink whose melting point is lower than room temperature, and the liquid metal ink Contains liquid metal.

Preferably, the electrospinnable elastomer is polyvinyl alcohol with a molecular weight of 30000-60000 g/mol.

Preferably, the specific process of preparing the base film layer is as follows: dissolving the electrospinnable elastomer in a solvent to form an electrospun polymer solution, and electrospinning the electrospun polymer solution on a receiving substrate to obtain an elastic spinning base film layer; the mass percentage concentration of the electrospinnable elastomer in the electrospun polymer solution is 15wt%-25wt%.

Preferably, the receiving substrate includes a drum, and the elastic spinning solution is electrospun on the outer wall of the drum along the circumferential direction of the drum; the liquid supply speed during electrospinning is 0.01ml/min-3ml/min , the applied positive voltage is 5-30KV, and the distance between the electrospinning nozzle and the receiving substrate or the composite layer of the liquid metal wire/elastic spinning base film is 8-20cm.

Preferably, the liquid metal ink also includes a solvent and a surfactant.

Preferably, the surfactant is selected from one or more of the following: polyvinylpyrrolidone, fluorocarbon surfactant, disodium lauryl sulfosuccinate monoester, Span, Tween, dodecylbenzenesulfonate sodium lauryl phosphate, potassium lauryl phosphate;

Preferably, the solvent includes at least one of deionized water, tetrahydrofuran, and ethanol;

Preferably, the mass fraction of the surfactant in the conductive ink is 0.05-0.1%; the concentration of the liquid metal is 0.1-5 g/ml.

Preferably, the solvent, the surfactant and the liquid metal are mixed and then ultrasonicated. The ultrasonic power is 150-300W, the time is 2-3min, and the temperature is -5-10°C.

Preferably, the liquid metal ink forms a pattern of interdigitated electrodes on the base film layer by coating, and scrapes the pattern on the surface of the base film layer through a mold to form an interdigitated electrode circuit.

Preferably, the liquid metal is selected from one or more of the following: gallium, mercury, gallium-indium alloy, gallium-indium-tin alloy, bismuth-tin alloy, and bismuth-tin-lead-indium alloy.

A wearable sensing device includes the elastic interdigital electrode sensor as described above.

The beneficial effects of the present invention are as follows: the elastic interdigital electrode sensor provided by the present invention has the advantages of good stretchability, high conductivity, suitable for large-area preparation, comfortable and breathable, recyclable and high stability, especially the unexpected , which have both contact and non-contact dual-mode responses, and both are excellent. Further as a human-computer interaction interface, unique functions such as wireless control and overload alarm can be realized.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. For those of ordinary skill in the art, obtaining other drawings based on these drawings still belongs to the scope of the present invention without any creative effort.

Fig. 1 is a flow chart of the preparation of elastic interdigitated electrodes provided by Embodiment 1 of the present invention;

Fig. 2 is a base film layer polyvinyl alcohol electrospun fiber (a) scanning electron microscope (SEM) diagram, (b) diameter distribution diagram and (c) air permeability diagram of Example 1 of the present invention;

Fig. 3 is a schematic diagram of the tensile stress-strain curve of the base film layer according to the embodiment of the present invention;

Fig. 4 is the scanning electron microscope (SEM) figure of embodiment one EGaIn-PVA of the present invention in inactive state;

Fig. 5 is the scanning electron microscope (SEM) figure of embodiment one EGaIn-PVA of the present invention in activation state;

Fig. 6 is the tensile sample digital photo of the embodiment of the present invention one EGaIn-PVA;

Fig. 7 is the digital photograph of EGaIn-PVA printing interdigital electrode of embodiment of the present invention;

Fig. 8 is a digital photo of the printed pattern of EGaIn-PVA in Example 1 of the present invention under folding (a), stretching (b), bending (c) and twisting (d);

9 is a schematic diagram of the resistance growth rate of EGaIn-PVA under different bending radii according to Embodiment 1 of the present invention;

10 is a schematic diagram of the resistance growth rate of EGaIn-PVA at different twist angles according to Embodiment 1 of the present invention;

Fig. 11 is a schematic diagram of the cycle test curves of 9000 and 7500 times of the EGaIn-PVA subsection of the embodiment of the present invention under the bending radius of 2cm and the torsion angle of 180°;

12 is a schematic diagram of the working principle of an EGaIn-PVA capacitive sensor according to an embodiment of the present invention;

Fig. 13 is a schematic diagram of the pressure sensitivity curve of an EGaIn-PVA capacitive sensor according to an embodiment of the present invention;

14 is a schematic diagram of a response time curve of an EGaIn-PVA capacitive sensor according to an embodiment of the present invention;

Fig. 15 is a short-press capacitance change data diagram of an EGaIn-PVA capacitive sensor according to an embodiment of the present invention under different numbers of fingers;

Fig. 16 is a long-press capacitance change data diagram of an EGaIn-PVA capacitive sensor according to an embodiment of the present invention under different numbers of fingers;

17 is a schematic diagram of a cyclic response time curve of an EGaIn-PVA capacitive sensor according to an embodiment of the present invention;

Figure 18 is an embodiment of the present invention, an EGaIn-PVA capacitive sensor displaying Morse code data by pressing and touching, (a) is a Morse code map, (b) is sending "HELLO" Morse through the EGaIn-PVA capacitive sensor The capacitance change data graph of the password, (c) is the capacitance change data graph of the "SOS" Morse code issued by the EGaIn-PVA capacitive sensor;

Fig. 19 is a schematic diagram (a)-(b) and data diagram (c) of pressure visualization of an EGaIn-PVA capacitive sensor according to an embodiment of the present invention;

Fig. 20 is the relative capacitance change of the EGaIn-PVA capacitive sensor of the embodiment of the present invention when the finger is close to different distances between 0 and 5 cm;

Fig. 21 is the relative capacitance change of the EGaIn-PVA capacitive sensor in the embodiment of the present invention when the palm moves in different moving directions (working distance = 1cm);

Fig. 22 is the capacitive response of the sensor to different 1~4 fingers under the same working distance (working distance=1cm) of the EGaIn-PVA capacitive sensor according to the embodiment of the present invention;

Fig. 23 is the capacitance change of the EGaIn-PVA capacitive sensor to the bending angle of the finger according to the embodiment of the present invention (working distance = 1cm);

Fig. 24 is the non-touch detection performance that the embodiment of the present invention one (EGaIn-PVA capacitive sensor) opens and closes to palm;

Fig. 25 is a schematic diagram of the capacitance change response data fed back by the EGaIn-PVA capacitive sensor according to the object material (a) and the object type (b) according to the embodiment of the present invention;

Fig. 26 is a schematic diagram of water level change data that can be monitored by an EGaIn-PVA capacitive sensor according to an embodiment of the present invention;

Fig. 27 is a schematic diagram of the capacitance change response data when the EGaIn-PVA capacitive sensor is operated in the syringe according to the embodiment of the present invention;

Fig. 28 is a schematic diagram of the degradation and recovery of the EGaIn-PVA capacitive sensor according to the embodiment of the present invention;

Fig. 29 is a schematic diagram of a digital photo of a single interdigital electrode sensor according to Embodiment 2 of the present invention;

Fig. 30 is a digital photo of the Arduino main control circuit board at the car end of the second embodiment of the present invention;

Fig. 31 is a schematic diagram of circuit wiring of the Arduino main control circuit board at the car end of the second embodiment of the present invention;

Fig. 32 is a digital photo of the Arduino main control circuit board at the remote control end of the second embodiment of the present invention;

Fig. 33 is a schematic diagram of circuit wiring of the Arduino main control circuit board at the remote control terminal according to Embodiment 2 of the present invention;

Fig. 34 is a schematic diagram of the analog signal data at the trolley end in Embodiment 2 of the present invention, and the two diagrams are respectively different analog signals;

Fig. 35 is a schematic diagram of the movement of the trolley and the operation of the remote control terminal in the second embodiment of the present invention;

Fig. 36 is a schematic diagram of the control interface of the Snake game in Embodiment 2 of the present invention, and the two pictures are respectively different control directions;

Figure 37 is a schematic diagram of the operation and principle of the pressure alarm in Embodiment 2 of the present invention, (a) is a schematic diagram of the principle, (b) is a schematic diagram of the operation, and (c) is a schematic diagram of the data set for the pressure alarm;

Fig. 38 is a performance comparison diagram of the two-digit electrode capacitance sensor according to the embodiment of the present invention.

detailed description

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings.

The invention provides an elastic interdigital electrode sensor, which includes an elastic conductor composite film, the elastic conductor composite film includes a base film layer and a conductive layer coated on the surface of the base film layer, and the base film layer is made of electrospun The elastomer is prepared by an electrospinning process, and the conductive layer is an interdigitated electrode circuit formed on the base film layer with a liquid metal ink whose melting point is lower than room temperature, and the liquid metal ink contains liquid metal.

Among them, the electrospinnable elastomer is specifically a series of degradable polymer elastomers that can be used for electrospinning in the prior art. Preferably, the mechanical properties of the elastic film formed by electrospinning (such as elasticity, strength, Anti-deformation and other properties) good degradable polymer elastomers, such as polyvinyl alcohol, polylactic acid, polycaprolactone, etc. Specifically, you can choose according to your needs. In some embodiments of the present invention, the electrospinnable elastomer adopts polyvinyl alcohol with a molecular weight of 30000-60000 g/mol.

The specific process of preparing the base film layer is as follows: dissolve the electrospinnable elastomer in a solvent to form an electrospun polymer solution, and electrospin the electrospun polymer solution on a receiving substrate to obtain an elastic spinning base film layer; The mass percent concentration of the electrospinnable elastomer in the electrospun polymer solution is 15wt%-25wt%.

Wherein, the solvent is selected from water and/or dimethyl sulfoxide, preferably water.

Wherein, in some embodiments of the present invention, polyvinyl alcohol is used for electrospinning. During the spinning process, the receiving substrate includes a drum, and the elastic spinning solution is electrospun on the drum along the circumferential direction of the drum. On the outer wall of the drum; the liquid supply rate during electrospinning is 0.01ml/min-3ml/min, the applied positive voltage is 5-30KV, the electrospinning nozzle and the receiving substrate or the liquid metal wire/elastic spinning substrate The distance between the film composite layers is 8-20cm.

The liquid metal ink also includes a solvent and a surfactant.

The surfactant is selected from one or more of the following: polyvinylpyrrolidone, fluorocarbon surfactant, disodium lauryl sulfosuccinate monoester, Span, Tween, sodium dodecylbenzenesulfonate, Potassium dodecyl phosphate;

The solvent includes at least one of deionized water, tetrahydrofuran, and ethanol;

The mass fraction of the surfactant in the conductive ink is 0.05-0.1%; the concentration of the liquid metal is 0.1-5 g/ml, preferably 2-4 g/ml, most preferably 3 g/ml.

The solvent, the surfactant and the liquid metal are mixed and then ultrasonicated. The ultrasonic power is 150-300W, the time is 2-3min, and the temperature is 5-10°C.

The liquid metal ink forms the interdigital electrode pattern on the base film layer by coating, and scrapes the interdigital electrode circuit on the surface of the base film layer through a mold to form the interdigital electrode circuit. The coating method can be one or more combinations of scraping, brushing, screen printing, and inkjet printing, but it should be understood that the coating method is not limited to the above-mentioned multiple coating methods , any coating method that can coat the coating material on the surface of the base film layer to form an alloy layer without essential difference is regarded as the technical solution protected by the present invention.

In some embodiments of the present invention, the screen printing method is adopted, and the screen printing plate is made by manually engraving a paint film or photochemical plate-making, and the scraper printing is used to transfer the liquid metal ink to the electrospun fiber through the mesh of the screen plate. On the film, a conductive layer can be directly formed on the surface of the base film layer.

In some embodiments of the present invention, screen printing is used to make EGaIn form an alloy layer on the surface of the base film layer. At this time, the alloy layer is temporarily non-conductive. The microstructure is shown in Figure 4. The liquid metal particles are coated with surfactant Wrapping barrier, at this time, it is also necessary to use post-processing to activate the liquid metal printing conductive path, specifically to use a mold to assist re-scraping activation on the surface of the alloy layer, and its microstructure is shown in Figure 5. The mold used is a tool with a certain hardness, such as tweezers, wire, scraper, etc., and it only needs to be wiped gently with the tool when it is activated.

The liquid metal is selected from one or more of the following: gallium, mercury, gallium-indium alloy, gallium-indium-tin alloy, bismuth-tin alloy, bismuth-tin-lead-indium alloy; more preferably, the liquid metal is a gallium-indium eutectic alloy .

Embodiment one:

As shown in Figure 1, the EGaIn-PVA capacitive sensor was prepared by the following steps:

Step S1: dissolving the electrospinnable polyvinyl alcohol elastomer in water to form an electrospun polymer solution, and the mass percent concentration of polyvinyl alcohol in the obtained polymer solution is 15wt%-25wt%. The preparation of electrospinning basement film, collecting electrospinning on a steel plate, and controlling the thickness of the basement film layer by controlling the collection time, the longer the collection time, the thicker the basement film layer, and stop the current electrospinning process after reaching the preset thickness , the microscopic size diagram is shown in Figure 2, showing excellent air permeability. Remove the base film layer from the steel plate, the tensile stress-strain curve of the base film layer is shown in Figure 3, the tensile strain can reach 263%, the Young's modulus is 0.68MPa, and it has good tensile resistance;

Step S2: Mix the polyvinylpyrrolidone aqueous solution and the liquid metal to obtain conductive ink, and the liquid metal is a gallium-indium eutectic alloy (eutectic Gallium-Indium alloy, EGaIn), wherein the mass ratio of the two elements of gallium-indium is 75: 25;

Step S3. Coating conductive ink on the surface of the base film layer by screen printing to form an interdigital electrode pattern as shown in Figure 7, and then scrape by tweezers to activate the conductive ink to obtain an elastic interdigital electrode sensor (in this paper Expressed with EGaIn-PVA).

EGaIn-PVA has good flexibility in the natural state and in the state of stretching, twisting, bending, and folding, as shown in Figure 6 and Figure 8 . As shown in Figure 9-11, the resistance changes of EGaIn-PVA under stretching, bending and twisting states were tested respectively, and the resistance value of the composite film tended to be stable all the time. It can be seen that EGaIn-PVA has good electrical conductivity and electrical stability. have obvious advantages.

As shown in Figure 12, EGaIn-PVA can be applied to wearable sensing devices. Fix EGaIn-PVA on the splint, change the environment medium of the interdigital electrode sensor by finger touch, and record the curve of the capacitance value of the composite film changing with finger pressure under pressure, as shown in Figure 13. The maximum sensitivity is 1.24KPa ^-1 , and the response The time is about 100ms, as shown in Figure 14.

EGaIn-PVA can form an interdigitated electrode array, each interdigitated electrode in the interdigitated electrode array includes a plurality of sub-electrodes, and each sub-electrode corresponds to a wavelength, wherein the sub-electrodes with the same wavelength have their electrode width W and electrode gap G is equal, sub-electrodes with different wavelengths have different electrode widths W, and electrode lengths L of all sub-electrodes of the same interdigitated electrode are equal. The pole plates of the interdigitated electrodes can be adjusted, preferably, the number of pole plates is between 3 and 10.

Preferably, the interdigital electrode arrays are all attached to the same flexible base film layer.

Before the application of touch pressure, the area of the electrode-electrolyte interface between the finger and the elastic interdigital electrode sensor is small. However, after the touch pressure is applied, the area forming the electrode-electrolyte interface between the finger and the elastic interdigital electrode sensor increases due to the deformation of the microstructure. According to the calculation formula of capacitance

Among them, C is the capacitance value of the capacitor, ε is the dielectric constant of the material, S is the actual electrode sensing area, k is the electrostatic force constant, and d is the sensing distance. The change in capacitance is due to the constant change in the dielectric constant ε of the material.

Use the LCR bridge meter to test the real-time capacitance change of the elastic interdigital electrode sensor under different finger pressures, as shown in Figure 15-16. To evaluate the capacitive sensing performance of elastic interdigital electrode sensors, the capacitive pressure sensitivity SC was defined as δ(ΔC/C0)/δP, where ΔC is the change in capacitance, _C0 is the original capacitance, and δP is the change in applied pressure. In addition, the cycle performance of the conductor composite film sensor was tested under low pressure, as shown in Figure 17.

As shown in Figure 18, it shows the application of interdigital electrodes as Morse code sensors. We compare the short press to the short dot signal “・” in Morse code, and the long press to the long signal “—”, which can be calculated according to The number of consecutive long and short presses expresses the specific letter signal of the Morse code, which reflects the excellent application prospect of the interdigital electrode sensor.

As shown in Figure 19, the application of the interdigital electrode array in pressure visualization is demonstrated. Nine identical sensors are connected in parallel to form a 3*3 interdigital electrode sensor matrix. The sensor array can sense the 3D signal distribution of the object pressure. . When the object is placed at different positions on the surface of the 3×3 sensor array, different capacitance value changes are fed back according to the pressure.

In addition to the contact sensing mode, the interdigital electrode sensor also exhibits non-contact sensing capabilities. As shown in Figure 20, the environmental permittivity ε is changed when the finger is constantly approaching the interdigital electrode, resulting in a change in capacitance. Similarly, at the same distance, the capacitance changes of the finger in different motion directions were tested, as shown in Figure 21. At the same time, the sensor also exhibits outstanding detection capabilities for various gestures, including capacitive sensing for finger bending angles, numbers, and palm opening and closing, as shown in Figures 22-24.

As shown in Figure 25, the interdigitated electrodes can also feed back different capacitance change responses according to the material, shape and size of the object. The capacitance responses of FEP, PET, Paper, and PP at a height of 1 cm directly above the sensor are different, and the same Yes, the phenomenon is the same when plastic, ceramic, and metal products are placed directly above the sensor at the same distance, which shows that the sensor has excellent object recognition ability in non-contact mode.

Since water itself is a very good dielectric material, the water in the environment will also affect the capacitance of the interdigital electrode. The capacitance response of different water levels has been tested. It can be seen from Figure 26-27 that the interdigital electrode The electrode sensor has a certain ability to detect the water level. There is a certain capacitance change at different water levels. And the interdigitated electrode capacitive sensor can be easily degraded in water, as shown in FIG. 28 .

Embodiment two:

In this example, the elastic interdigital electrode sensor prepared in Example 1 is used in a Bluetooth remote control car. Figure 29 shows the electrical connection method of the elastic interdigital electrode sensor.

A remote control car based on a single-chip microcomputer, including a car end and a remote control end, the car end and the remote control end are connected through wireless, and the car end includes a control module, a driving motor and a mobile power supply.

Among them, the specific structure of the trolley is shown in Figure 30, and the specific circuit configuration is shown in Figure 31. Its control module is connected to the wireless Bluetooth of the remote control terminal through the wireless module of the car, and the control module is electrically connected to the drive motor. The mobile power supply adopts dual power supplies. The dual power supplies supply different voltages to the control module and the drive motor, and one of the power supplies uses 6V to supply power to the drive motor and the Arduino microcontroller.

Among them, the specific structure of the remote control terminal is shown in Figure 32, and the specific circuit configuration is shown in Figure 33. It is controlled by the interdigital electrode capacitance sensor, and the signal is sent to the car terminal through the Bluetooth sending module. The control module can use Arduino single-chip microcomputer. Set at least four control buttons to control the front, rear, left, and right of the car. If other functions are required, additional buttons can be added. Each button needs to be connected to a 5~10kΩ pull-up resistor and connected to the pin A0~9 data input port , and the other end is connected to GND. When the button is inactive, each button is low level, and when it is active, the corresponding button becomes high level. The four buttons are connected to A3, A4, A5 and A6 respectively. By continuously collecting the state of the switch, it is judged whether the corresponding key is pressed. Send a signal if a key is closed. If no key is pressed, the status information is collected again.

The wireless module uses two HC-06 Bluetooth modules for master-slave mode binding, and the remote control end is connected to the car end through the remote control wireless Bluetooth module.

The motor drive module can use L293D, and the specific circuit settings are shown in Figure 33. L293D can drive four motors. The PWM signal terminals of the DC motors M1~M4 are respectively connected to the IC1-IC4 (1, 9, 11, 13) pins of the L293D chip to input control levels to control the forward and reverse rotation of the motor.

The main control part is mainly composed of single-chip microcomputer, driver chip, Bluetooth receiving module and DC motor. The wireless Bluetooth receives information, the single-chip microcomputer analyzes the data, and then calls the Arduino subroutine to control the action of the DC motor. The tasks to be completed in system software design include the following three parts.

First, the design of the main program, use arduino software to compile the main program, and generate the ino file;

Second, the design of the circuit schematic diagram, use Fritzing software to make the circuit schematic diagram;

3. Download the program. Use arduino software to download the ino file generated during program compilation to the main control microcontroller Arduino UNO, and download the program compiled ino file corresponding to the remote control car to the microcontroller Arduino UNO (2).

As shown in Figure 34, the analog signal of the sensor is consistent with the serial port signal of the arduino port. The schematic diagram of the operation of the sensor is shown in Figure 35. The commands are forward, backward, left turn, and right turn. As shown in Figure 36, the remote control terminal can also be connected to the computer, correspondingly, forward, backward, left turn, and right turn also correspond to the movement of the snake, which further reflects the application field of the sensor.

As shown in Figure 37, the interdigital electrode sensor can also be used in a pressure alarm, place your finger on the sensor, and by applying different amounts of force, the indicator light will light up (the greater the force, the more light is on), If the threshold set by the pressure sensor is exceeded, a red light (alarm) lights up.

As shown in Figure 38, the data graph shows the comparison of the six functional indicators of the sensor in the literature in this field: sensitivity, response time, lag time, recyclability, contact, and non-contact mode. It is obvious that the sensor has excellent performance.

Those of ordinary skill in the art can understand that all or part of the steps in the method of the above-mentioned embodiments can be completed by instructing related hardware through a program, and the program can be stored in a computer-readable storage medium, and the storage Media such as ROM/RAM, magnetic disk, optical disk, etc.

The above disclosures are only preferred embodiments of the present invention, and certainly cannot limit the scope of rights of the present invention. Therefore, equivalent changes made according to the claims of the present invention still fall within the scope of the present invention.

Claims (10)

1. an elastic interdigital electrode sensor, is characterized in that, wherein comprises elastic conductor composite film, and described elastic conductor composite film comprises base film layer and is coated on the conductive layer on base film layer surface, and described base film layer is adopted The electrospinnable elastomer is prepared by an electrospinning process, and the conductive layer is at least one interdigitated electrode circuit formed on the base film layer with a liquid metal ink whose melting point is lower than room temperature, and the liquid metal ink contains liquid Metal. 2. The elastic interdigital electrode sensor according to claim 1, characterized in that: the electrospinnable elastomer is polyvinyl alcohol with a molecular weight of 30000-60000 g/mol. 3. The elastic interdigital electrode sensor according to claim 2, characterized in that, the specific process of preparing the base film layer is as follows: dissolving the electrospinning elastomer in a solvent to form an electrospinning polymer solution, said electrospinning The polymer solution is electrospun on the receiving substrate to obtain an elastic spinning base film layer; the mass percentage concentration of the electrospinnable elastic body in the electrospun polymer solution is 15wt%-25wt%. 4. The elastic interdigital electrode sensor according to claim 3, wherein the receiving substrate comprises a drum, and the elastic spinning solution is electrospun on the outer side wall of the drum along the circumferential direction of the drum; The liquid supply rate during electrospinning is 0.01ml/min-3ml/min, the applied positive voltage is 5-30KV, and the distance between the electrospinning nozzle and the receiving substrate or the composite layer of the liquid metal wire/elastic spinning base film is 8-20cm. 5 . The elastic interdigital electrode sensor according to claim 1 , characterized in that: the liquid metal ink further includes a solvent and a surfactant. 5 . 6. The elastic interdigital electrode sensor according to claim 4, characterized in that: the surfactant is selected from one or more of the following: polyvinylpyrrolidone, fluorocarbon surfactant, lauryl sulfosuccinic acid mono Disodium Ester, Span, Tween, Sodium Dodecyl Benzene Sulfonate, Potassium Dodecyl Phosphate; The solvent includes at least one of deionized water, tetrahydrofuran, and ethanol; The mass fraction of the surfactant in the conductive ink is 0.05-0.1%; the concentration of the liquid metal is 0.1-5g/ml. 7. The elastic interdigital electrode sensor according to claim 6, characterized in that: the solvent, the surfactant and the liquid metal are mixed and ultrasonicated, the ultrasonic power is 150-300W, the time is 2-3min, and the temperature is -5~10℃. 8. The elastic interdigital electrode sensor according to claim 5, characterized in that: the liquid metal ink forms the pattern of the interdigital electrode on the base film layer by coating, and scrapes the surface of the base film layer by the mold. coated to form an interdigitated electrode circuit. 9. The elastic interdigital electrode sensor according to claim 1, wherein the liquid metal is selected from one or more of the following: gallium, mercury, gallium-indium alloy, gallium-indium-tin alloy, bismuth-tin alloy, bismuth tin-lead-indium alloy. 10. A wearable sensor device, characterized in that it comprises the elastic interdigital electrode sensor according to any one of claims 1-9.

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