CN-122016099-A - Piezoresistive flexible sensor

Abstract

The invention provides a piezoresistive flexible sensor, and belongs to the field of sensors. The preparation method of the piezoresistive flexible sensor comprises the following steps of immersing foam plastic in a solution containing at least conductive polymer, drying to obtain conductive foam, and arranging at least two electrodes on any surface of the conductive foam to obtain the piezoresistive flexible sensor, wherein the conductive polymer is polybenzodifurandione. The piezoresistive flexible sensor provided by the invention has the advantages of high sensitivity, wide detection range, quick response and recovery, light flexible structure, simple and mature preparation process and the like.

Inventors

• Cui Yatu
• XU JIE
• GU GUANGXIN

Assignees

• 复旦大学

Dates

Publication Date

20260512

Application Date

20260116

Claims (10)

1. 1. The piezoresistive flexible sensor is characterized in that the preparation method comprises the following steps: Soaking the foam plastic in a solution containing at least conductive polymer, and drying to obtain conductive foam; at least two electrodes are arranged on any surface of the conductive foam to obtain the piezoresistive flexible sensor, Wherein, the the conductive polymer is polybenzodifurandiones.
2. 2. The piezoresistive flexible sensor according to claim 1, characterized in that: wherein the solvent of the solution is DMSO.
3. 3. The piezoresistive flexible sensor according to claim 1, characterized in that: Wherein the number average molecular weight of the polybenzodifurandione is 10 ten thousand-50 ten thousand Daltons.
4. 4. The piezoresistive flexible sensor according to claim 1, characterized in that: Wherein the foam has a pore size of 20 μm to 200. Mu.m.
5. 5. The piezoresistive flexible sensor according to claim 1, characterized in that: wherein the foam plastic is selected from any one of polyurethane foam plastic, polystyrene foam plastic, polyvinyl chloride foam or melamine foam plastic.
6. 6. The piezoresistive flexible sensor according to claim 1, characterized in that: Wherein the solution also contains conductive filler.
7. 7. The piezoresistive flexible sensor according to claim 6, characterized in that: Wherein the filler is selected from any one or more of silver nanowires, single-walled carbon nanotubes, multi-walled carbon nanotubes, single-layer MXene, multi-layer MXene or graphene.
8. 8. The piezoresistive flexible sensor according to claim 6, characterized in that: wherein the filler is silver nanowire with the diameter of 20nm-200nm and the length of5 mu m-50 mu m.
9. 9. The piezoresistive flexible sensor according to claim 1, characterized in that: wherein the concentration of the conductive polymer in the solution containing at least the conductive polymer is 0.5-7.5mg/mL.
10. 10. The piezoresistive flexible sensor according to claim 1, characterized in that: Wherein the temperature is 80-100 ℃ and the time is 4-8h in the drying process.

Description

Piezoresistive flexible sensor Technical Field The invention relates to the field of sensors, in particular to a piezoresistive flexible sensor. Background With the rapid development of internet of things (IoT), artificial Intelligence (AI), wearable devices, soft robots, and human-computer interaction technologies, traditional rigid, cumbersome sensors have failed to meet new application scenarios. The market has created a great need for flexible sensors that can accommodate complex curved surfaces, and that are stretchable and lightweight. Piezoresistive pressure sensors operate using the piezoresistive effect. When certain materials are subjected to mechanical stress (e.g., extrusion or stretching), their own resistivity may change. By measuring this change in resistance, the magnitude of the applied pressure can be accurately extrapolated. The sensor based on the effect is the main stream of research because of simple structure, convenient signal processing and high response speed. However, conventional piezoresistive sensors face challenges towards flexibility. Conventional piezoresistive materials, such as single crystal silicon, are mainly rigid, brittle materials, although highly sensitive (high gauge factor), and are not suitable for flexible applications because they cannot withstand large deformations. The key to developing flexible piezoresistive sensors is the structural design. Porous structures (e.g., sponges, foams) have extremely high compressibility, ultra-light mass and large specific surface area. When pressed, the beam inside it can bend, contact and separate widely, resulting in an exponential change in the number of conductive paths. The sensing mechanism of the contact resistance is dominant, and the intrinsic resistance change caused by deformation of the material is not caused, so that the ultra-high sensitivity and the extremely-wide detection range can be brought. How to impart the conductive properties to a three-dimensional porous insulating substrate is a key process step in the implementation of such sensors. In the prior art, a template method is mainly adopted, for example, square sugar and salt particles are used as templates, and after the conductive composite material is filled, the templates are dissolved and removed. The method has good controllability, but the process is complex, and the large-area preparation is difficult. Disclosure of Invention The present invention has been made to solve the above problems, and an object of the present invention is to provide a piezoresistive flexible sensor having advantages of simple manufacturing method, low density, high sensitivity, and the like. The invention provides a piezoresistive flexible sensor, which has the characteristics that the preparation method comprises the following steps: Soaking the foam plastic in a solution containing at least conductive polymer, and drying to obtain conductive foam; at least two electrodes are arranged on any surface of the conductive foam to obtain the piezoresistive flexible sensor, Wherein, the the conductive polymer is polybenzodifurandiones. The piezoresistive flexible sensor provided by the invention can also be characterized in that the solvent of the solution is DMSO. The piezoresistive flexible sensor provided by the invention can be further characterized in that the number average molecular weight of the polybenzodifurandione is 10 ten thousand-50 ten thousand Daltons. In the piezoresistive flexible sensor provided by the invention, it may also be characterized in that the foam has a pore size of 20 μm to 200 μm, preferably the foam has a pore size of 100 μm. The piezoresistive flexible sensor provided by the invention can be characterized in that the foam plastic is any one of polyurethane foam plastic, polystyrene foam plastic, polyvinyl chloride foam plastic or melamine foam plastic. The piezoresistive flexible sensor provided by the invention can also be characterized in that the solution also contains conductive filler. The piezoresistive flexible sensor provided by the invention can be further characterized in that the filler is selected from any one or more of silver nanowires, single-wall carbon nanotubes, multi-wall carbon nanotubes, single-layer MXene, multi-layer MXene or graphene. The piezoresistive flexible sensor provided by the invention can be further characterized in that the filler is a silver nanowire with the diameter of 20nm-200nm and the length of 5 μm-50 μm. The piezoresistive flexible sensor provided by the invention can be further characterized in that the concentration of the conductive polymer in the solution containing at least the conductive polymer is 0.5-7.5mg/mL. The piezoresistive flexible sensor provided by the invention can be further characterized in that the temperature is 80-100 ℃ and the time is 4-8 hours in the drying process. Preferably, the temperature during drying is 80 ℃ and the time is 4 hours. Effects and effects of the invention