Novel flexible resistance-type strain sensor based on electrostatic spinning and preparation method and application thereof

Abstract

The invention relates to a novel flexible resistance-type strain sensor based on electrostatic spinning, which comprises a Zn / PEO conductive fiber and a polyurethane (PU) packaging film, the Zn / PEO conductive fiber is spirally wrapped by the PU packaging film, the whole body is in a one-dimensional linear spiral shape, and the Zn / PEO conductive fiber is a metal conductive fiber prepared from ink through electrostatic spinning. The novel flexible resistance type strain sensor is high in sensitivity, simple in structure, good in tensile property and mechanical property and low in power consumption in the preparation and use process, and is applied to the field of human-computer interaction.

Description

Technical Field

[0001] The present invention relates to the field of flexible electronic technology, and in particular to a manufacturing method and application of a novel flexible resistive strain sensor based on electrostatic spinning. Background Art

[0002] The field of human-computer interaction has made significant progress in smart healthcare, robotics, and smart homes. As the technology in this field matures, more and more smart devices are used in people's daily lives. Most of these interactive devices need to collect and analyze the user's physiological information. Therefore, how to stably collect, transmit, and process the user's physiological data becomes crucial. To meet such needs, flexible technology has emerged. Flexible devices are highly adaptable and can fit the human body shape, providing a more comfortable experience. In addition, advanced sensor technology can accurately capture and encode human body signals and track complex movements, thereby bringing users a more personalized and customized interactive experience.

[0003] In recent years, new sensing materials with excellent performance, such as conductive hydrogels and liquid metals, have been successfully used to manufacture wearable strain sensors for human health monitoring and human-computer interaction applications. However, flexible strain sensors still face many challenges in practical applications, such as complex integration process, high integrated power consumption, and irreconcilable limitations in ultra-high tensile and high mechanical strength tensile detection. Therefore, it is crucial to develop a new type of flexible resistive strain sensor with high sensitivity, high tensile strength, high mechanical properties, ultra-low power consumption, and simple process, which provides an innovative solution for the application of flexible electronic technology in the field of human-computer interaction. Summary of the invention

[0004] In order to solve at least one of the defects of the above-mentioned prior art, the present invention provides a new flexible resistive strain sensor based on electrospinning and a preparation method thereof, which has high sensitivity, simple structure, good tensile and mechanical properties, low power consumption during preparation and use, and is applied to the field of human-computer interaction.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] A novel flexible resistive strain sensor based on electrospinning comprises Zn / PEO conductive fibers and a PU packaging film, wherein the PU packaging film wraps the Zn / PEO conductive fibers in a spiral shape, and the whole is in a one-dimensional linear spiral shape, and the Zn / PEO conductive fibers are metal conductive fibers made of ink by electrospinning.

[0007] A method for preparing a novel flexible resistive strain sensor based on electrospinning, the specific steps are as follows:

[0008] (1) Using micron-thick PU as the substrate, the needle is connected to the positive electrode of a high-voltage power supply;

[0009] (2) preparing ink, storing the ink in a syringe, and delivering it to a needle through a precision syringe pump, applying an electric field force generated by a high voltage between the needle and the substrate as a driving force, so that the ink forms a single strand of nanofiber yarn at the needle, and the yarn is repeatedly stacked in one dimension on the PU surface to form Zn / PEO conductive fibers;

[0010] (3) Wrapping Zn / PEO conductive fibers in a unidimensional linear spiral with PU film;

[0011] (4) Silver paste and wire are used as electrodes and fixed at both ends of the Zn / PEO conductive fiber to obtain a new type of flexible resistive strain sensor.

[0012] More preferably, the thickness of the PU film is between 10um and 100um.

[0013] More preferably, the thickness of the single strand of nanofiber yarn is between 10 nm and 100 nm.

[0014] Application of a novel flexible resistive strain sensor based on electrospinning prepared by any of the above preparation methods, wherein the novel flexible resistive strain sensor is used in the field of human-computer interaction.

[0015] The above technical solution has the following beneficial effects:

[0016] 1) The present invention provides a novel flexible resistive strain sensor based on electrospinning, which is in a one-dimensional linear spiral shape. The spiral structure enables the Zn / PEO conductive fiber to adhere well to the PU film, and the device has good softness. At the same time, the structure provides a large telescopic range, so that the sensor has excellent sensing performance in the strain range of 0.5% to 1400%, including high sensitivity (response time of 417.2ms, recovery time of 386.3ms) and high repeatability (up to 5000 cycles).

[0017] 2) The present invention provides a method for preparing a novel flexible resistive strain sensor based on electrospinning, which is simple and does not require a complex preparation process. The metal conductive fiber made of ink by electrospinning can undergo redox reaction at room temperature, so it can still show good stability without post-treatment, and its resistance value is at the megohm level, which greatly reduces the integrated power consumption of the sensor and is convenient for large-scale production and use.

[0018] 3) The present invention provides an application of a new type of flexible resistive strain sensor based on electrospinning, which can be applied to various fields such as human motion detection, human-computer interaction, and smart cars. The strain sensor can be adhered to various parts of the human body and other organisms. When the user exercises, the strain sensor will produce tensile deformation. The size of its output electrical signal is related to the deformation amount. Through the collected motion signal, the speed and intensity of human movement can be monitored in real time, and posture correction and sports injury warning can be performed. It shows broad application prospects in the future healthy exercise system and rehabilitation medical field. The strain sensor provided by the present invention has the remarkable characteristics of high sensitivity, good mechanical properties, and simple preparation. The smart gloves made of it can accurately recognize gestures, showing the potential of the sensor in user recognition, human-computer interaction, and remote control of robots. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the flexible resistive strain sensor of the present invention;

[0020] Figure 2 A schematic diagram of electrospinning during the preparation of the flexible resistive strain sensor of the present invention;

[0021] Figure 3 The flowchart of the method for preparing the flexible resistive strain sensor of the present invention;

[0022] Figure 4 is a response recovery time diagram of the flexible resistive strain sensor of the present invention;

[0023] Figure 5 is a response diagram of the flexible resistive strain sensor of the present invention at 1400% ultimate tensile strength;

[0024] Figure 6 The flexible resistive strain sensor of the present invention is subjected to 5000 times of continuous repeated stretching cycle test under 10% strain;

[0025] Figure 7 , 8 , 9 and 10 are schematic diagrams of realizing robot car control using the flexible resistive strain sensor of the present invention. DETAILED DESCRIPTION

[0026] In order to explain the technical content, structural features, achieved objectives and effects of the technical solution in detail, the following is a detailed description in conjunction with specific embodiments and accompanying drawings.

[0027] Embodiment 1:

[0028] 1) Using micron-thick PU as the substrate, a needle with an outer diameter of 0.23 mm and an inner diameter of 0.08 mm was connected to the positive electrode of a high-voltage power supply (DW-SA403-1ACE5, Tianjin Dongwen High Voltage Power Supply Co., Ltd., China).

[0029] 2) Prepare a zinc-ammine complex ink with a mass fraction of 5% zinc acetate, a mass fraction of 14% PEO, a volume ratio of water to anhydrous ethanol of 1:2, and a molar ratio of zinc acetate to isopropanolamine of 1:5. Dissolve 0.25 g zinc acetate in 1.44 g deionized water, then add 2.27 g ethanol, 0.42 g C 3 H 9 NO and 0.6 g PEO, and the mixture was stirred at 25 °C for 48 h.

[0030] 3) The ink was stored in a 1 ml syringe (Jiangsu Zhiyu Medical Equipment Co., Ltd., China) and delivered to the needle by a precision syringe pump (Pump 11Pico Plus Elite, Harvard Apparatus, USA). The PU was wrapped on the drum of an electrospinning machine (QZNT-E01-01, Foshan Qingzi Precision Measurement and Control Technology Co., Ltd., China), and the rotor drove the drum to rotate at a set speed to ensure that the yarn could be linearly and evenly stacked on the PU surface.

[0031] 4) Conductive fibers were prepared on a micron-thick PU substrate using electrospinning technology. The electric field force generated by applying a high voltage between the needle and the substrate was used as a driving force, so that the ink formed a single strand of nanofiber yarn at the needle. The yarn was repeatedly stacked in one dimension on the PU surface to form Zn / PEO conductive fibers.

[0032] 5) Use PU film to wrap Zn / PEO conductive fibers in a unidimensional linear spiral shape.

[0033] 6) Silver paste and wire are used as electrodes and fixed at both ends of the Zn / PEO conductive fiber.

[0034] like Figure 1 As shown, in the flexible resistive strain sensor of the present invention, the Zn / PEO conductive fiber 1 is a metal conductive fiber made of zinc-ammine complex ink 5 by electrostatic spinning, and the PU packaging film 2 wraps the Zn / PEO conductive fiber 1 in a spiral shape, and the whole is in a one-dimensional linear spiral shape. The excellent conductivity of the nano-scale conductive fiber and the excellent film-forming performance of PU provide a close contact interface for the sensor.

[0035] like Figure 2As shown, under high voltage, the zinc-ammine complex ink 5 is electrospun to form a single strand of nanofiber yarn 6, which is repeatedly stacked on the surface of the PU packaging film 2 to form Zn / PEO conductive fiber 1, and then the obtained Zn / PEO conductive fiber 1 is post-treated without sintering. The zinc-ammine complex ink 5 uses water and ethanol as solvents and is formed by the complexation of zinc ions and isopropanolamine. The thickness of the PU film 2 is between 10um and 100um, and the thickness of the single strand of nanofiber yarn 6 is between 10nm and 100nm.

[0036] like Figure 3 As shown, the preparation method is simple and does not require complicated preparation processes. The metal conductive fiber made from zinc-ammine complex ink by electrospinning can undergo redox reaction at room temperature, so it can still show good stability without the need for post-treatment, and its resistance is at the megohm level, which greatly reduces the integrated power consumption of the sensor and is convenient for large-scale production and use.

[0037] like Figure 4 As shown, in the process of being stretched at an extremely fast rate and then released to return to the initial state, the sensor responds quickly with almost negligible hysteresis. The short response time (417.2ms) and short recovery time (386.3ms) demonstrate the high sensitivity of the sensor.

[0038] Figure 5 The response diagram of the flexible resistive strain sensor of the present invention under 1400% ultimate tensile strength is shown. When stress exists, the spiral structure causes it to deform evenly along the axial direction, alleviating the mismatch of Young's modulus during stretching. At the same time, the structure provides a larger telescopic range, resulting in high mechanical properties and high tensile strength of the sensor.

[0039] Figure 6 The response diagram of the flexible resistive strain sensor of the present invention after 5000 continuous repeated stretching cycle tests at a strain of 10% is shown. It can be seen that the sensor still maintains a stable and sensitive resistance change after a long test of 2 hours, with almost no performance loss during the test.

[0040] Figure 7 , 8 , 9, and 10 are application diagrams of the flexible resistive strain sensor of the present invention to realize the control of the robot car. Figure 7 The schematic diagram of the wireless stress data interaction glove is shown in the figure. Four sensors are tightly attached to the joints of the right index finger and middle finger to make a wireless stress data interaction glove. The finger bending / unbending state generates different resistance signals. Through different gestures, the resistance can achieve a stable and sensitive 1024 signal, where the finger straight is 0 and the bent finger is 1. Figure 8, insert the sensor electrode into a specific hardware module, and transmit the gesture signal to the robot car through Bluetooth through digital-to-analog conversion and signal processing, so as to realize remote control of the car. According to the algorithm settings, the left middle finger, left index finger, right middle finger, and right index finger are A, B, C, and D respectively. Different gestures correspond to different signals, that is, they correspond to different states of the car. For example, clenching both hands (ABCD / 1111) controls the car to move forward, opening both hands (ABCD / 0000) controls the car to stop, and clenching the right fist (ABCD / 1100) controls the car to turn left at a large angle. In addition, there is also control of different turning angles of the car, etc. The specific signal control is as follows: Fig. 9 As shown. Through the above control of the car's behavior, the car can smoothly drive on the track. (As shown Fig.10 ).

[0041] Although the above embodiments have been described, once those skilled in the art know the basic creative concepts, they can make additional changes and modifications to these embodiments. Therefore, the above description is only an embodiment of the present invention and does not limit the patent protection scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the specification and drawings of the present invention, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A novel flexible resistive strain sensor based on electrospinning, characterized in that: The invention comprises Zn / PEO conductive fiber and polyurethane (PU) packaging film, wherein the PU packaging film wraps the Zn / PEO conductive fiber in a spiral shape, and the whole is in a one-dimensional linear spiral shape; the Zn / PEO conductive fiber is a metal conductive fiber made of ink by electrostatic spinning.

2. The method for preparing a novel flexible resistive strain sensor based on electrospinning according to claim 1, characterized in that: The specific steps are as follows: (1) Using micron-thick PU as the substrate, the needle is connected to the positive electrode of a high-voltage power supply; (2) preparing ink, storing the ink in a syringe, and delivering it to a needle through a precision syringe pump, applying an electric field force generated by a high voltage between the needle and the substrate as a driving force, so that the ink forms a single strand of nanofiber yarn at the needle, and the yarn is repeatedly stacked in one dimension on the PU surface to form Zn / PEO conductive fibers; (3) Wrapping Zn / PEO conductive fibers in a unidimensional linear spiral with PU film; (4) Silver paste and wire are used as electrodes and fixed at both ends of the Zn / PEO conductive fiber to obtain a new type of flexible resistive strain sensor.

3. The preparation method according to claim 2, characterized in that: The thickness of the PU film is between 10um and 100um.

4. The preparation method according to claim 2, characterized in that: The thickness of the single strand of nanofiber yarn is between 10nm and 100nm.

5. An application of a novel flexible resistive strain sensor based on electrospinning prepared according to any one of claims 2 to 4, characterized in that: The novel flexible resistive strain sensor is used in the field of human-computer interaction.

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