Piezoresistive sensor designed by imitating micro hair on legs of stray spiders and preparation method of piezoresistive sensor

Abstract

The invention belongs to the technical field of sensor manufacturing, and discloses a piezoresistive sensor with stray spider leg fuzz design and a preparation method thereof.The piezoresistive sensor with stray spider leg fuzz design comprises a flexible substrate with the surface provided with a plurality of shovel-shaped fuzz structures; the flexible electrode is arranged below the plurality of shovel-shaped micro-hair structures; the flexible substrate is in contact with the flexible electrode through a plurality of shovel-shaped micro-hair structures, and the shovel-shaped micro-hair structures can deform under the action of pressure, so that the contact area of the flexible substrate and the flexible electrode is changed; the flexible electrode is used for generating corresponding current according to the contact area with the flexible substrate; the current is used for determining a corresponding pressure value. Through the piezoresistive sensor which is provided with a plurality of shovel-shaped micro-hair structures on the surface and imitates the micro-hair design of the legs of the stray spiders, the sensitivity and the response precision of the piezoresistive sensor are improved.

Description

Technical Field

[0001] The present application relates to the technical field of sensor manufacturing, and in particular to a piezoresistive sensor designed to imitate the micro-hairs on the legs of a wandering spider and a method for preparing the same. Background Art

[0002] Flexible sensors are strain sensors that can sense changes in external pressure under deformation conditions such as bending and stretching. They are usually made of elastomeric polymers and conductive materials, and have good flexibility and biocompatibility. Flexible sensors designed based on the bionics of plants and animals in nature have broad application prospects in the fields of biomedicine, robotics, and intelligent electronic devices. For example, it can be used to develop highly sensitive medical diagnostic equipment, smart prostheses, smart manipulator gripping, and soft robot skin.

[0003] At present, there is still a lot of room for improvement in the response speed, detection accuracy, environmental adaptability and intelligent perception of flexible sensors. The current solutions mainly focus on imitating biological perception, various microstructure designs and research on new materials. However, the mechanical stability of existing bionic sensors is insufficient. The microstructure may suffer from mechanical fatigue or damage under long-term use or high-frequency pressure changes, affecting the stability and life of the sensor. In addition, in some application scenarios, the response speed and response accuracy of these bionic sensors still cannot meet the requirements.

[0004] Therefore, in order to solve the technical problems of existing bionic sensors such as insufficient sensitivity and insufficient response accuracy, there is an urgent need for a piezoresistive sensor designed to imitate the micro-hairs on the legs of a wandering spider and a preparation method thereof. Summary of the invention

[0005] The purpose of the present application is to provide a piezoresistive sensor designed to imitate the micro-hairs on the legs of a wandering spider and a preparation method thereof. Through the corresponding preparation method, a piezoresistive sensor designed to imitate the micro-hairs on the legs of a wandering spider is prepared, which is composed of a flexible substrate with a plurality of shovel-shaped micro-hair structures on the surface and a flexible electrode arranged under the plurality of shovel-shaped micro-hair structures. The piezoresistive sensor solves the problems of existing bionic sensors such as insufficient sensitivity and insufficient response accuracy. The sensor can convert pressure changes into changes in the contact area between the shovel-shaped micro-hair structure and the flexible electrode, thereby improving the sensitivity and response accuracy of the piezoresistive sensor.

[0006] In a first aspect, the present application provides a piezoresistive sensor designed to imitate the micro-hairs on the legs of a wandering spider, comprising a flexible substrate having a plurality of shovel-shaped micro-hair structures on its surface, and a flexible electrode disposed under the plurality of the shovel-shaped micro-hair structures; The flexible substrate is in contact with the flexible electrode through a plurality of the shovel-shaped micro-hair structures, and the shovel-shaped micro-hair structures can be deformed under pressure, thereby changing the contact area between the flexible substrate and the flexible electrode; The flexible electrode is used to generate a corresponding current according to the contact area with the flexible substrate; the current is used to determine the corresponding pressure value.

[0007] The piezoresistive sensor designed to imitate the micro-hairs on the legs of a wandering spider provided in the present application can detect pressure. The piezoresistive sensor designed to imitate the micro-hairs on the legs of a wandering spider, which is composed of a flexible substrate with a plurality of shovel-shaped micro-hair structures on the surface and a flexible electrode arranged under the plurality of shovel-shaped micro-hair structures, can detect pressure, thereby solving the problems of existing bionic sensors such as insufficient sensitivity and insufficient response accuracy. The sensor can convert pressure changes into changes in the contact area between the shovel-shaped micro-hair structures and the flexible electrode, thereby improving the sensitivity and response accuracy of the piezoresistive sensor.

[0008] Optionally, the flexible electrode is provided with a finger electrode; the finger electrode comprises a positive electrode, a negative electrode, a group of positive fingers and a group of negative fingers, the positive fingers are connected to the positive electrode, the negative fingers are connected to the negative electrode, and the positive fingers and the negative fingers are arranged alternately; the shovel-shaped micro-hair structure is arranged one by one opposite to the gap between the positive fingers and the negative fingers, and the shovel-shaped micro-hair structure can change the contact area between the flexible electrode and the flexible substrate at the gap between the positive fingers and the negative fingers under the action of pressure, thereby changing the dielectric resistance of the gap between the positive fingers and the negative fingers, causing the capacitance between the positive fingers and the negative fingers to change, thereby forming a current.

[0009] The piezoresistive sensor designed to imitate the micro-hairs on the legs of a wandering spider provided in the present application can detect pressure. When subjected to pressure, the deformation of the shovel-shaped micro-hair structure can change the contact area with the interdigitated electrodes, thereby converting the pressure change into a resistance change between the flexible substrate and the flexible electrode, so that the flexible electrode can generate a corresponding current change according to the resistance change. The corresponding pressure value can be determined by the changed current, which is beneficial to improving the detection efficiency of the piezoresistive sensor.

[0010] Optionally, the shovel-shaped micro-hair structure is a shovel-shaped structure; the end of the shovel-shaped micro-hair structure away from the flexible substrate is shovel-shaped; the end surface of the shovel-shaped end of the shovel-shaped micro-hair structure is a concave surface that gradually moves away from the flexible electrode from both ends to the middle.

[0011] Optionally, the length of the shovel-shaped micro-hair structure does not exceed 600 μm, and the distance between adjacent shovel-shaped micro-hair structures is 150 μm-250 μm.

[0012] Optionally, the flexible substrate further comprises a piezoresistive sensitive layer disposed on the outer surface of the shovel-shaped micro-hair structure.

[0013] Optionally, the flexible electrode further comprises a polyvinyl alcohol fiber layer disposed on the upper surface of the interdigital electrode; The polyvinyl alcohol fiber layer is used to reduce the initial current and tunneling current between the flexible substrate and the flexible electrode.

[0014] In a second aspect, the present application provides a method for preparing a piezoresistive sensor designed to imitate the micro-hairs on the legs of a wandering spider, which is applied to prepare the piezoresistive sensor designed to imitate the micro-hairs on the legs of a wandering spider as described above, comprising: obtaining materials for making a flexible substrate; After degassing the manufacturing material to obtain a liquid material, the liquid material is poured on a flexible substrate template with a shovel-shaped groove by using a template method to prepare a second flexible substrate with a plurality of shovel-shaped micro-hair structures on the surface; Spraying a material solution corresponding to the piezoresistive sensitive layer on the outer surface of the second flexible substrate to prepare a third flexible substrate having the piezoresistive sensitive layer disposed on the outer surface; The third flexible substrate is attached to the interdigital electrode with the polyvinyl alcohol fiber layer to obtain a piezoresistive sensor designed to imitate the micro-hairs on the legs of a wandering spider.

[0015] The method for preparing a piezoresistive sensor designed to imitate the micro-hairs on the legs of a wandering spider comprises the following steps: pouring a liquid material corresponding to a degassed flexible substrate on a flexible substrate template with shovel-shaped grooves to prepare a second flexible substrate with a plurality of shovel-shaped micro-hair structures on the surface; spraying a material solution corresponding to a piezoresistive sensitive layer on the outer surface of the second flexible substrate and attaching interdigital electrodes with a polyvinyl alcohol fiber layer to prepare a piezoresistive sensor designed to imitate the micro-hairs on the legs of a wandering spider. The method solves the problems of existing bionic sensors such as insufficient sensitivity and insufficient response accuracy, and can convert pressure changes into changes in the contact area between the shovel-shaped micro-hair structure and the flexible electrode, thereby improving the sensitivity and response accuracy of the piezoresistive sensor.

[0016] Optionally, after degassing the manufacturing material to obtain a liquid material, the liquid material is poured on a flexible substrate template with a shovel-shaped groove by using a template method to prepare a second flexible substrate with a plurality of shovel-shaped micro-hair structures on the surface, comprising: Degassing the production material to obtain a liquid material corresponding to the production material; The liquid material is poured on a flexible substrate template with a shovel-shaped groove, and after natural drying, it is peeled off from the flexible substrate template to obtain a preliminary second flexible substrate; According to the preset sensor size, the preliminary second flexible substrate is cut and modified to obtain a second flexible substrate with a plurality of shovel-shaped micro-hair structures arranged on the surface.

[0017] Optionally, spraying a material solution corresponding to the piezoresistive sensitive layer on the outer surface of the second flexible substrate to prepare a third flexible substrate having the piezoresistive sensitive layer disposed on the outer surface thereof comprises: Preparing a material solution corresponding to the piezoresistive sensitive layer; Adding a curing agent to the material solution, and spraying the material solution mixed with the curing agent on the outer surface of the second flexible substrate to obtain a preliminary third flexible substrate; The preliminary third flexible substrate is polished according to a preset sensor size to obtain a third flexible substrate with the piezoresistive sensitive layer disposed on the outer surface.

[0018] Optionally, the third flexible substrate is attached to the interdigital electrode with the polyvinyl alcohol fiber layer to obtain a piezoresistive sensor designed to imitate the micro-hairs on the legs of a wandering spider, comprising: A polyvinyl alcohol fiber layer is prepared on the surface of the interdigital electrode by an electrospinning method to obtain an interdigital electrode with a polyvinyl alcohol fiber layer attached thereto; The third flexible substrate is attached to the interdigital electrode with the polyvinyl alcohol fiber layer by using a thermoplastic film packaging method, so as to prepare the piezoresistive sensor designed to imitate the micro-hairs on the legs of a wandering spider.

[0019] Beneficial effect: The present application provides a piezoresistive sensor designed to imitate the micro-hairs on the legs of a wandering spider and a preparation method thereof. The liquid material corresponding to the degassed flexible substrate is poured onto a flexible substrate template with shovel-shaped grooves to prepare a second flexible substrate with a plurality of shovel-shaped micro-hair structures on the surface. The material solution corresponding to the piezoresistive sensitive layer is sprayed on the outer surface of the second flexible substrate and interdigitated electrodes with a polyvinyl alcohol fiber layer are adhered to obtain a piezoresistive sensor designed to imitate the micro-hairs on the legs of a wandering spider, which is composed of a flexible substrate with a plurality of shovel-shaped micro-hair structures on the surface and flexible electrodes arranged under the plurality of shovel-shaped micro-hair structures. The piezoresistive sensor solves the problems of existing bionic sensors such as insufficient sensitivity and insufficient response accuracy, and can convert pressure changes into changes in the contact area between the shovel-shaped micro-hair structures and the flexible electrodes, thereby improving the sensitivity and response accuracy of the piezoresistive sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A schematic diagram of the structure of a piezoresistive sensor designed to imitate the micro-hairs on the legs of a wandering spider provided in an embodiment of the present application.

[0021] Figure 2A flow chart of a method for preparing a piezoresistive sensor designed to imitate the micro-hairs on the legs of a wandering spider provided in an embodiment of the present application.

[0022] Figure 3 A schematic diagram of the structure of the shovel-shaped micro-hair structure provided in an embodiment of the present application.

[0023] Figure 4 A schematic diagram of the structure of the interdigitated electrodes provided in an embodiment of the present application.

[0024] Explanation of reference numerals: 1. flexible substrate; 2. flexible electrode; 3. shovel-shaped microhair structure; 4. piezoresistive sensitive layer; 5. polyvinyl alcohol fiber layer; 6. interdigitated electrode. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0026] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. At the same time, in the description of this application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0027] Please refer to Figure 1 , Figure 1 It is a piezoresistive sensor designed to imitate the micro-hair of the legs of a wandering spider in some embodiments of the present application, which is used to detect pressure, and includes a flexible substrate 1 with a plurality of shovel-shaped micro-hair structures 3 on the surface, and a flexible electrode 2 arranged under the plurality of shovel-shaped micro-hair structures 3; The flexible substrate 1 contacts the flexible electrode 2 via a plurality of shovel-shaped micro-hair structures 3. The shovel-shaped micro-hair structures 3 can be deformed under pressure, thereby changing the contact area between the flexible substrate 1 and the flexible electrode 2. The flexible electrode 2 is used to generate a corresponding current according to the contact area with the flexible substrate 1; the current is used to determine the corresponding pressure value.

[0028] In a specific application, the shovel-shaped micro-hair structure 3 is manufactured by imitating the structure and function of the micro-hairs on the legs of a wandering spider. The micro-hairs on the legs of a wandering spider have extremely high sensitivity. The wandering spider can accurately sense tiny vibrations and airflow changes in the environment through the micro-hair structure of its legs. By simulating the structure and function of the micro-hairs on the legs of a wandering spider, the sensor (a piezoresistive sensor designed to imitate the micro-hairs on the legs of a wandering spider) can achieve high sensitivity and high-precision pressure detection.

[0029] A flexible electrode 2 is arranged under the shovel-shaped micro-hair structure 3. When the sensor is not subjected to pressure, the shovel-shaped micro-hair structure 3 is in slight contact with the flexible electrode 2. When pressure is applied to the sensor, the shovel-shaped micro-hair structure 3 can effectively capture tiny pressure changes and thus produce deformation, thereby changing the contact area between the flexible substrate 1 and the flexible electrode 2 (i.e., changing the contact area between the shovel-shaped micro-hair structure 3 and the flexible electrode 2). This change in contact area can be directly converted into a change in current and resistance, thereby realizing rapid and accurate detection of pressure.

[0030] The piezoresistive sensor designed to imitate the micro-hairs on the legs of a wandering spider detects pressure through a flexible substrate with a plurality of shovel-shaped micro-hair structures on the surface and a flexible electrode arranged under the plurality of shovel-shaped micro-hair structures, thereby solving the problems of existing bionic sensors such as insufficient sensitivity and insufficient response accuracy. The piezoresistive sensor can convert pressure changes into changes in the contact area between the shovel-shaped micro-hair structures and the flexible electrode, thereby improving the sensitivity and response accuracy of the piezoresistive sensor.

[0031] Specifically, the flexible electrode 2 is provided with a finger electrode 6; the finger electrode 6 includes a positive electrode, a negative electrode, a group of positive fingers and a group of negative fingers, the positive fingers are connected to the positive electrode, the negative fingers are connected to the negative electrode, and the positive fingers and the negative fingers are arranged alternately; the shovel-shaped micro-hair structure 3 is arranged one by one opposite to the gap between the positive fingers and the negative fingers, and the shovel-shaped micro-hair structure 3 can change the contact area between the flexible electrode 2 and the flexible substrate 1 at the gap between the positive fingers and the negative fingers under the action of pressure, thereby changing the dielectric resistance of the gap between the positive fingers and the negative fingers, causing the capacitance between the positive fingers and the negative fingers to change, thereby forming a current.

[0032] In a specific application, the interdigitated electrode 6 is located below the shovel-shaped micro-hair structure 3 and is a key component for achieving accurate pressure detection. The interdigitated electrode 6 includes a positive electrode, a negative electrode, a group of positive interdigitated fingers and a group of negative interdigitated fingers. The positive interdigitated fingers are connected to the positive electrode, and the negative interdigitated fingers are connected to the negative electrode. The positive interdigitated fingers and the negative interdigitated fingers are arranged alternately. Under the action of pressure, an extrusion phenomenon occurs between the shovel-shaped micro-hair structure 3 and the interdigitated electrode 6, causing the shovel-shaped micro-hair structure 3 to deform, so as to change the contact area between the interdigitated electrode 6 and the shovel-shaped micro-hair structure 3, resulting in a change in the dielectric resistance of the interval between the positive interdigitated fingers and the negative interdigitated fingers, causing the capacitance between the positive interdigitated fingers and the negative interdigitated fingers to change, thereby changing the current between the flexible substrate 1 and the flexible electrode 2.

[0033] The interdigitated electrodes 6 are usually made of a material with good conductivity, such as gold, silver or graphene. The design of the interdigitated structure in the interdigitated electrodes 6 increases the effective area of ​​the electrode and improves the sensitivity of current detection. The width and spacing of the interdigitated structure in the interdigitated electrodes 6 can be optimized as needed. Figure 4 As shown, Figure 4 This is a schematic diagram of the structure of the interdigital electrode provided in an embodiment of the present application, wherein c and d are both interdigital structures in the interdigital electrode 6.

[0034] When external pressure acts on the sensor, the shovel-shaped micro-hair structure 3 of the flexible substrate 1 will be deformed, resulting in a change in the contact area with the interdigitated electrode 6. This change causes the current in the interdigitated electrode 6 to change. The sensor can accurately capture this current change and accurately determine the corresponding pressure value through the pre-established pressure-current relationship curve.

[0035] Specifically, the shovel-shaped micro-hair structure 3 is a shovel-shaped structure; the end of the shovel-shaped micro-hair structure 3 away from the flexible substrate 1 is in a shovel-shaped shape (that is, the end in contact with the flexible electrode 2 is in a shovel-shaped shape); the end surface of the shovel-shaped end of the shovel-shaped micro-hair structure 3 is a concave surface that gradually moves away from the flexible electrode 2 from both ends to the middle (specifically, Figure 3 as shown).

[0036] In specific applications, the shovel-shaped micro-hair structure 3 is a key component of a piezoresistive sensor designed to imitate the micro-hairs on the legs of a wandering spider. Figure 3 As shown, where a is the end close to the flexible substrate 1, and b is the end away from the flexible substrate 1. Figure 3 It can be seen that the end of the shovel-shaped micro-hair structure 3 away from the flexible substrate 1 (i.e., end b) is in a shovel shape, and the end surface of this end (end b) is a concave surface that gradually moves away from the flexible electrode 2 from both ends to the middle, that is, the thickness of the end of the shovel-shaped micro-hair structure 3 that is in a shovel shape gradually decreases in the direction close to the flexible electrode 2. This concave design imitates the structure of the micro-hair on the legs of a wandering spider, which can more effectively capture and transmit external pressure and help improve the response speed of the sensor.

[0037] When the sensor is not under pressure, the shovel-shaped micro-hair structure 3 is in slight contact with the interdigital electrode 6 through the concave surface. When pressure is applied to the sensor surface, the shovel-shaped micro-hair structure 3 is squeezed toward the interdigital electrode 6 and quickly deformed. This deformation will quickly change the contact area between the concave surface and the interdigital electrode 6 (the contact area will increase rapidly when pressure is applied, and will decrease rapidly when pressure is removed. The rapid change in contact area can improve the sensitivity and response accuracy of the sensor), resulting in a change in the contact area between the flexible substrate 1 and the flexible electrode 2, thereby causing a rapid current change in the interdigital electrode 6, which helps to improve the response speed of the sensor.

[0038] The materials of the flexible substrate 1 and the shovel-shaped microhair structure 3 include any one of polydimethylsiloxane, organic platinum silicone, polyurethane, hydrogel, and thermoplastic elastomer materials. These materials have good elasticity and durability and can maintain structural integrity after repeated deformation.

[0039] Specifically, the length of the shovel-shaped micro-hair structure 3 does not exceed 600 μm, and the distance between adjacent shovel-shaped micro-hair structures 3 is 150 μm-250 μm.

[0040] In specific applications, the length and spacing design of the shovel-shaped microhair structure 3 plays an important role in solving the problems of sensor sensitivity and response speed. The length of the shovel-shaped microhair structure 3 does not exceed 600μm. This design ensures that the microhair structure is small enough to respond sensitively to tiny pressure changes. At the same time, this length limit also helps to maintain the mechanical stability of the microhair structure and prevent bending or breaking during use. The distance between adjacent shovel-shaped microhair structures 3 is 150μm-250μm (generally set to 200μm). This spacing design can ensure enough microhair structures while avoiding interference between adjacent microhairs. Appropriate spacing enables each microhair structure to sense pressure changes independently, thereby improving the overall sensitivity and accuracy of the sensor.

[0041] By precisely controlling the length and spacing of the shovel-shaped microhair structure 3, the sensitivity and response speed of the sensor can be effectively improved. When external pressure acts on the sensor, the shovel-shaped microhair structure 3 with a length not exceeding 600 μm will be slightly bent or compressed. Since the shovel-shaped microhair structure 3 is short, this deformation can quickly change the contact area between the flexible substrate 1 and the flexible electrode 2, thereby affecting the current and resistance between the flexible substrate 1 and the flexible electrode 2, so that the sensor can more accurately reflect the change in pressure.

[0042] Specifically, the flexible substrate 1 further includes a piezoresistive sensitive layer 4 arranged on the outer surface of the shovel-shaped micro-hair structure 3 .

[0043] In a specific application, the piezoresistive sensitive layer 4 is arranged on the outer surface of the shovel-shaped micro-hair structure 3, that is, between the shovel-shaped micro-hair structure 3 and the flexible electrode 2. The piezoresistive sensitive layer 4 can directly sense the deformation of the shovel-shaped micro-hair structure 3 to produce corresponding changes, and quickly convert the pressure change into resistance change. This design not only improves the sensitivity of the sensor, enabling it to detect smaller pressure changes, but also shortens the signal transmission path, thereby improving the response speed.

[0044] The material of the piezoresistive sensitive layer 4 includes one or more of carbon-based conductive materials, pure conductive metals, nanoparticles, and high molecular polymers. These materials have good flexibility and piezoresistive properties and can produce significant resistance changes under slight deformation. The piezoresistive sensitive layer 4 can be directly deposited on the surface of the shovel-shaped micro-hair structure 3 by spraying, spin coating, or printing.

[0045] The thickness and uniformity of the piezoresistive sensitive layer 4 have an important influence on the performance of the sensor. Generally, the thickness of the piezoresistive sensitive layer can be controlled within the range of 10-100 nanometers to ensure its good flexibility and sensitivity. In order to improve the uniformity of the piezoresistive sensitive layer, multiple coating and annealing treatment methods can be used.

[0046] Furthermore, the piezoresistive sensitive layer 4 can be designed with a multi-layer structure. For example, a layer of conductive polymer can be first coated on the surface of the shovel-shaped micro-hair structure 3, and then covered with a layer of carbon nanotube network. This multi-layer structure can combine the advantages of different materials to further improve the performance of the sensor.

[0047] Specifically, the flexible electrode 2 further includes a polyvinyl alcohol fiber layer 5 disposed on the upper surface of the interdigital electrode 6; The polyvinyl alcohol fiber layer 5 is used to reduce the initial current and tunneling current between the flexible substrate 1 and the flexible electrode 2 .

[0048] In a specific application, the polyvinyl alcohol fiber layer 5 is located above the interdigital electrode 6 and directly contacts the flexible substrate 1. This layer of fiber has good insulation properties and can effectively reduce the initial current and tunneling current. The initial current refers to the small current between the flexible substrate 1 and the flexible electrode 2 when there is no external pressure; the tunneling current is the current caused by electrons passing through the insulating layer due to the quantum tunneling effect. Both currents affect the sensitivity and accuracy of the sensor.

[0049] From the above, it can be seen that the piezoresistive sensor designed to imitate the micro-hairs on the legs of a wandering spider detects pressure through a flexible substrate with a plurality of shovel-shaped micro-hair structures on the surface and a flexible electrode arranged under the plurality of shovel-shaped micro-hair structures. It solves the problems of existing bionic sensors such as insufficient sensitivity and insufficient response accuracy, and can convert pressure changes into changes in the contact area between the shovel-shaped micro-hair structure and the flexible electrode, thereby improving the sensitivity and response accuracy of the piezoresistive sensor.

[0050] refer to Figure 2 The present application provides a method for preparing a piezoresistive sensor designed to imitate the micro-hairs on the legs of a wandering spider, which is used to prepare the piezoresistive sensor designed to imitate the micro-hairs on the legs of a wandering spider as described above, comprising the steps of: Step S101, obtaining materials for making a flexible substrate; Step S102, after degassing the manufacturing material to obtain a liquid material, the liquid material is poured on a flexible substrate template with a shovel-shaped groove by using a template method to prepare a second flexible substrate with a plurality of shovel-shaped micro-hair structures on the surface; Step S103, spraying a material solution corresponding to the piezoresistive sensitive layer on the outer surface of the second flexible substrate to prepare a third flexible substrate having a piezoresistive sensitive layer on the outer surface; Step S104, laminating the third flexible substrate onto the interdigital electrodes with the polyvinyl alcohol fiber layer, to obtain a piezoresistive sensor designed to imitate the micro-hairs on the legs of a wandering spider.

[0051] The method for preparing a piezoresistive sensor designed to imitate the micro-hairs on the legs of a wandering spider comprises the following steps: pouring a liquid material corresponding to a degassed flexible substrate on a flexible substrate template with shovel-shaped grooves to prepare a second flexible substrate with a plurality of shovel-shaped micro-hair structures on the surface; spraying a material solution corresponding to a piezoresistive sensitive layer on the outer surface of the second flexible substrate and attaching interdigital electrodes with a polyvinyl alcohol fiber layer to prepare a piezoresistive sensor designed to imitate the micro-hairs on the legs of a wandering spider. The method solves the problems of existing bionic sensors such as insufficient sensitivity and insufficient response accuracy, and can convert pressure changes into changes in the contact area between the shovel-shaped micro-hair structure and the flexible electrode, thereby improving the sensitivity and response accuracy of the piezoresistive sensor.

[0052] Specifically, in step S101, a material for making the flexible substrate is obtained, including any one of polydimethylsiloxane (PDMS), organic platinum silicone, polyurethane, hydrogel, and thermoplastic elastomer.

[0053] Specifically, in step S102, after the manufacturing material is subjected to degassing treatment to obtain a liquid material, the liquid material is poured on a flexible substrate template with a shovel-shaped groove by using a template method to prepare a second flexible substrate with a plurality of shovel-shaped micro-hair structures on the surface, including: Degassing the production materials to obtain liquid materials corresponding to the production materials; The liquid material is poured on a flexible substrate template with a shovel-shaped groove, and after natural drying, it is peeled off from the flexible substrate template to obtain a preliminary second flexible substrate; According to the preset sensor size, the preliminary second flexible substrate is cut and modified to obtain a second flexible substrate with a plurality of shovel-shaped micro-hair structures arranged on the surface.

[0054] In step S102, first, the manufacturing material is degassed to obtain a liquid material corresponding to the manufacturing material. Then, the liquid material is poured on a flexible substrate template with a shovel-shaped groove, and after natural drying, it is peeled off from the flexible substrate template to obtain a preliminary second flexible substrate. Finally, according to the preset sensor size, the preliminary second flexible substrate is cut and modified to obtain a second flexible substrate with a plurality of shovel-shaped micro-hair structures on the surface.

[0055] Among them, degassing can be achieved in many ways, for example, vacuum degassing can be used to put the material into a vacuum container and evacuate to remove bubbles in the material; or ultrasonic degassing can be used to break bubbles by using the cavitation effect of ultrasonic waves. These methods can effectively remove bubbles in the material and improve the uniformity and stability of the material.

[0056] The template method uses a flexible substrate template with shovel-shaped grooves to precisely control the shape and size of the shovel-shaped microhair structure. The template can be made in a variety of ways. For example, the desired groove structure can be made on a silicon wafer using 3D printing technology, chemical etching, laser engraving, or micromachining technology. The material selection of the template is also very important. You can consider using flexible materials such as polydimethylsiloxane (PDMS) to facilitate the subsequent peeling process.

[0057] Natural drying can be carried out at room temperature or in a constant temperature and humidity environment to ensure the uniformity of the drying process. The drying time may need to be adjusted according to the characteristics of the material and environmental conditions, and may usually take 24-48 hours. This process can reduce the generation of internal stress in the material and improve the stability of the flexible substrate.

[0058] The peeling, cutting and modification steps are the final stages of preparing the second flexible substrate having a plurality of spatula-shaped microhair structures on the surface. The peeling process needs to be performed carefully to avoid damaging the microhair structure. Tweezers or a special peeling tool can be used to slowly peel from the edge of the template. Cutting can be performed using a precision cutting machine or laser cutting equipment to ensure the flatness of the cutting edge. The modification process may include fine-tuning the shape of the microhair structure or removing excess material, which can be completed using precision trimming tools or micromachining equipment.

[0059] Specifically, in step S103, a material solution corresponding to the piezoresistive sensitive layer is sprayed on the outer surface of the second flexible substrate to prepare a third flexible substrate having a piezoresistive sensitive layer on the outer surface, including: Preparing a material solution corresponding to the piezoresistive sensitive layer; Adding a curing agent to the material solution, and spraying the material solution mixed with the curing agent on the outer surface of the second flexible substrate to obtain a preliminary third flexible substrate; The preliminary third flexible substrate is polished according to a preset sensor size to obtain a third flexible substrate with a piezoresistive sensitive layer disposed on the outer surface.

[0060] In step S103, a material solution corresponding to the piezoresistive sensitive layer is prepared using a conductive material. For example, taking carbon nanotubes (CNT) and dimethylsiloxane (PDMS) as an example, the corresponding material solution is prepared: 1) according to the ratio of CNT to anhydrous ethanol of 1:20, the CNT treated with mixed acid is added to anhydrous ethanol, and then the anhydrous ethanol mixed with CNT is treated with a water bath ultrasonic device at a temperature of 25°C and a treatment time of 30 minutes to obtain a CNT suspension; 2) according to a ratio of 1:1, P DMS and anhydrous ethanol are mixed, and the mixed solution of PDMS and anhydrous ethanol is stirred using a magnetic stirrer at room temperature for 30 minutes to obtain a PDMS solution; 3) The CNT suspension and the PDMS solution are prepared into a mixed solution at a concentration ratio of 6% (the concentration ratio of the CNT suspension to the PDMS solution is 6:100), and then ultrasonically treated in a water bath at room temperature for 30 minutes, and then stirred at 70°C for 120 minutes using a magnetic stirrer until the anhydrous ethanol is completely evaporated, to obtain a material solution corresponding to the piezoresistive sensitive layer.

[0061] Use epoxy resin or other curing materials as curing agents, add 10% of the material solution mass into the solution, continue stirring for 30 minutes to ensure that the curing agent is evenly dispersed, and then put the mixture of material solution and curing agent into a vacuum pump for 30 minutes to remove bubbles.

[0062] According to the preset spraying interval time and the number of spraying times (for example, the number of spraying times is 4 times, and the interval time of each spraying is 10s, which can be set according to actual needs), the material solution mixed with the curing agent is sprayed on the outer surface of the second flexible substrate, and then the second flexible substrate with the mixed liquid of the material solution and the curing agent on the surface is placed in an oven for heating (for example, the temperature of the oven is set to 80°C for heating), and the mixed liquid is cured on the surface of the second flexible substrate by heating for 10 minutes to obtain a preliminary third flexible substrate.

[0063] According to the preset sensor size, the preliminary third flexible substrate is polished to optimize the surface quality and thickness uniformity of the piezoresistive sensitive layer, thereby obtaining a third flexible substrate with a piezoresistive sensitive layer disposed on the outer surface.

[0064] Specifically, in step S104, the third flexible substrate is attached to the interdigital electrode with the polyvinyl alcohol fiber layer to obtain a piezoresistive sensor designed to imitate the micro-hairs on the legs of a wandering spider, including: A polyvinyl alcohol fiber layer is prepared on the surface of the interdigital electrode by an electrospinning method to obtain an interdigital electrode with a polyvinyl alcohol fiber layer attached thereto; By using thermoplastic film packaging, the third flexible substrate was attached to the interdigital electrodes with a polyvinyl alcohol fiber layer, and a piezoresistive sensor designed to imitate the micro-hairs on the legs of a wandering spider was prepared.

[0065] In step S104, an electrospinning method is used to precisely control the diameter, density and distribution of the polyvinyl alcohol fiber layer by adjusting parameters such as voltage, flow rate, and collection distance during the electrospinning process, thereby improving the bonding strength between the polyvinyl alcohol fiber layer and the interdigital electrode, and obtaining an interdigital electrode with a polyvinyl alcohol fiber layer.

[0066] The third flexible substrate is bonded to the interdigital electrode with a polyvinyl alcohol fiber layer, and then the third flexible substrate is tightly bonded to the interdigital electrode by using the property of thermoplastic materials to soften after heating, so as to prepare a piezoresistive sensor designed to imitate the micro-hairs on the legs of wandering spiders. In specific operations, thermoplastic materials such as polyethylene, polypropylene or polyethylene terephthalate can be selected as packaging films. During the packaging process, the temperature is controlled in a range slightly lower than the melting point of the material. For example, for polyethylene, the temperature can be set at 110-130°C, and the pressure can be controlled at 0.1-1MPa for 1-5 minutes. This ensures that the film is in full contact with the substrate and the electrode to form a stable structure, that is, a piezoresistive sensor designed to imitate the micro-hairs on the legs of wandering spiders is prepared.

[0067] As can be seen from the above, the preparation method of the piezoresistive sensor designed to imitate the micro-hairs on the legs of wandering spiders comprises the following steps: obtaining a material for making a flexible substrate, degassing the material to obtain a liquid material, using a template method to cast the liquid material on a flexible substrate template with shovel-shaped grooves, so as to prepare a second flexible substrate with a plurality of shovel-shaped micro-hair structures on the surface, spraying a material solution corresponding to the piezoresistive sensitive layer on the outer surface of the second flexible substrate, preparing a third flexible substrate with a piezoresistive sensitive layer on the outer surface, and attaching the third flexible substrate to an interdigital electrode with a polyvinyl alcohol fiber layer to obtain a wandering spider-like micro-hair-shaped structure. A piezoresistive sensor designed with micro-hairs on the legs of a spider; thus, through the corresponding preparation method of the piezoresistive sensor designed with micro-hairs imitating the legs of a wandering spider, a piezoresistive sensor designed with micro-hairs imitating the legs of a wandering spider is prepared, which is composed of a flexible substrate with multiple shovel-shaped micro-hair structures on the surface and flexible electrodes arranged under the multiple shovel-shaped micro-hair structures. The sensor is used to detect pressure, solve the problems of existing bionic sensors such as insufficient sensitivity and insufficient response accuracy, and can convert pressure changes into changes in the contact area between the shovel-shaped micro-hair structure and the flexible electrode, thereby improving the sensitivity and response accuracy of the piezoresistive sensor.

[0068] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, and the indirect coupling or communication connection of the devices or units can be electrical, mechanical or other forms.

[0069] In addition, the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, and may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0070] Furthermore, the functional modules in the various embodiments of the present application may be integrated together to form an independent part, or each module may exist separately, or two or more modules may be integrated to form an independent part.

[0071] In this document, relational terms such as first and second, etc. are used merely to distinguish one entity or operation from another entity or operation, but do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0072] The above description is only an embodiment of the present application and is not intended to limit the protection scope of the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A piezoresistive sensor designed to imitate the microhairs on the legs of a wandering spider, used to detect pressure, characterized in that: It comprises a flexible substrate (1) having a plurality of shovel-shaped micro-hair structures (3) arranged on its surface, and a flexible electrode (2) arranged below the plurality of shovel-shaped micro-hair structures (3); The flexible substrate (1) contacts the flexible electrode (2) via a plurality of shovel-shaped micro-hair structures (3), and the shovel-shaped micro-hair structures (3) are capable of deforming under pressure, thereby changing the contact area between the flexible substrate (1) and the flexible electrode (2); The flexible electrode (2) is used to generate a corresponding current according to the contact area with the flexible substrate (1); The current is used to determine the corresponding pressure value.

2. The piezoresistive sensor designed to imitate the micro-hairs on the legs of a wandering spider according to claim 1, characterized in that: The flexible electrode (2) is provided with an interdigital electrode (6); the interdigital electrode (6) comprises a positive electrode, a negative electrode, a group of positive interdigits and a group of negative interdigits, the positive interdigits are connected to the positive electrode, the negative interdigits are connected to the negative electrode, and the positive interdigits and the negative interdigits are arranged alternately; the shovel-shaped micro-hair structure (3) is arranged one by one opposite to the interval between the positive interdigits and the negative interdigits, and the shovel-shaped micro-hair structure (3) can change the contact area between the flexible electrode (2) and the flexible substrate (1) at the interval between the positive interdigits and the negative interdigits under the action of pressure, thereby changing the dielectric resistance of the interval between the positive interdigits and the negative interdigits, causing the capacitance between the positive interdigits and the negative interdigits to change, thereby forming a current.

3. The piezoresistive sensor designed to imitate the micro-hairs on the legs of a wandering spider according to claim 2, characterized in that: The shovel-shaped micro-hair structure (3) is a shovel-shaped structure; one end of the shovel-shaped micro-hair structure (3) away from the flexible substrate (1) is in a shovel-shaped shape; the end surface of the shovel-shaped end of the shovel-shaped micro-hair structure (3) is a concave surface that gradually moves away from the flexible electrode (2) from both ends to the middle.

4. The piezoresistive sensor designed to imitate the micro-hairs on the legs of a wandering spider according to claim 3, characterized in that: The length of the shovel-shaped micro-hair structure (3) does not exceed 600 μm, and the distance between adjacent shovel-shaped micro-hair structures (3) is 150 μm-250 μm.

5. The piezoresistive sensor designed to imitate the micro-hairs on the legs of a wandering spider according to claim 4, characterized in that: The flexible substrate (1) further comprises a piezoresistive sensitive layer (4) arranged on the outer surface of the shovel-shaped micro-hair structure (3).

6. The piezoresistive sensor designed to imitate the micro-hairs on the legs of a wandering spider according to claim 5, characterized in that: The flexible electrode (2) further comprises a polyvinyl alcohol fiber layer (5) arranged on the upper surface of the interdigital electrode (6); The polyvinyl alcohol fiber layer (5) is used to reduce the initial current and tunneling current between the flexible substrate (1) and the flexible electrode (2).

7. A method for preparing a piezoresistive sensor designed to imitate the micro-hairs on the legs of a wandering spider, which is used to prepare the piezoresistive sensor designed to imitate the micro-hairs on the legs of a wandering spider as claimed in claim 6, characterized in that: include: obtaining materials for making a flexible substrate; After degassing the manufacturing material to obtain a liquid material, the liquid material is poured on a flexible substrate template with a shovel-shaped groove by using a template method to prepare a second flexible substrate with a plurality of shovel-shaped micro-hair structures on the surface; Spraying a material solution corresponding to the piezoresistive sensitive layer on the outer surface of the second flexible substrate to prepare a third flexible substrate having the piezoresistive sensitive layer disposed on the outer surface; The third flexible substrate is attached to the interdigital electrode with the polyvinyl alcohol fiber layer to obtain a piezoresistive sensor designed to imitate the micro-hairs on the legs of a wandering spider.

8. The method for preparing the piezoresistive sensor designed to imitate the micro-hairs on the legs of a wandering spider according to claim 7, characterized in that: After degassing the manufacturing material to obtain a liquid material, the liquid material is poured on a flexible substrate template with a shovel-shaped groove by using a template method to prepare a second flexible substrate with a plurality of shovel-shaped micro-hair structures on the surface, including: Degassing the production material to obtain a liquid material corresponding to the production material; The liquid material is poured on a flexible substrate template with a shovel-shaped groove, and after natural drying, it is peeled off from the flexible substrate template to obtain a preliminary second flexible substrate; According to the preset sensor size, the preliminary second flexible substrate is cut and modified to obtain a second flexible substrate with a plurality of shovel-shaped micro-hair structures arranged on the surface.

9. The method for preparing a piezoresistive sensor designed to imitate the micro-hairs on the legs of a wandering spider according to claim 7, characterized in that: The material solution corresponding to the piezoresistive sensitive layer is sprayed on the outer surface of the second flexible substrate to prepare a third flexible substrate having the piezoresistive sensitive layer disposed on the outer surface, comprising: Preparing a material solution corresponding to the piezoresistive sensitive layer; Adding a curing agent to the material solution, and spraying the material solution mixed with the curing agent on the outer surface of the second flexible substrate to obtain a preliminary third flexible substrate; The preliminary third flexible substrate is polished according to a preset sensor size to obtain a third flexible substrate with the piezoresistive sensitive layer disposed on the outer surface.

10. The method for preparing a piezoresistive sensor designed to imitate the micro-hairs on the legs of a wandering spider according to claim 7, characterized in that: The third flexible substrate is attached to the interdigital electrode with the polyvinyl alcohol fiber layer to obtain a piezoresistive sensor designed to imitate the micro-hairs on the legs of a wandering spider, comprising: A polyvinyl alcohol fiber layer is prepared on the surface of the interdigital electrode by an electrospinning method to obtain an interdigital electrode with a polyvinyl alcohol fiber layer attached thereto; The third flexible substrate is attached to the interdigital electrode with the polyvinyl alcohol fiber layer by using a thermoplastic film packaging method, so as to prepare the piezoresistive sensor designed to imitate the micro-hairs on the legs of a wandering spider.

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