Wide-range flexible resistance type pressure sensor and preparation method thereof

Abstract

The invention provides a wide-range flexible resistance type pressure sensor and a preparation method thereof, the sensor is of a multi-layer structure, the sensor comprises a lower packaging layer, a flexible substrate layer, a first conductive electrode, a composite sponge layer, a second conductive electrode and an upper packaging layer from bottom to top in sequence, and the inner side of the second conductive electrode is subjected to helium plasma irradiation etching to obtain a nanometer fluff structure. The composite sponge layer is obtained by compounding a sponge material and a conductive material through a solution impregnation method, and the conductive material with a lamellar structure is arranged in the composite sponge layer; and according to the invention, the pressure test sensitivity is improved through full contact of the electrode nano fluff structure and the hole structure, the sponge flexible skeleton is combined with the conductive material, the deformation of the sponge and the deformation of the conductive material are fully utilized, pressure sensitive mechanism switching is realized in different pressure ranges, the pressure detection range is expanded, and good linear response is kept in a wide range. The sensor provided by the invention has the advantages of simple structure manufacturing, small volume, light weight and biological harmlessness.

Description

technical field [0001] The invention relates to the fields of energy conversion technology, surface treatment technology, micro-electro-mechanical system (MEMS), and two-dimensional pressure-sensitive materials, in particular to a wide-range flexible resistive pressure sensor and a preparation method. Background technique [0002] Among the common physical quantities measured by sensors, pressure is one of the important parameters, and it exists in the aspects of cargo weighing identification, building structure stability monitoring, pipeline pressure monitoring, road traffic detection, pulse blood pressure monitoring, electronic skin touch and pressure sense, etc. Extensive measurement needs. With the improvement of people's living standards, people pay more and more attention to their own health status, especially the growing elderly population. Flexible wearable non-invasive detection of physiological parameters such as pulse, blood pressure, joint flexion and extension h...

AI Technical Summary

Problems solved by technology

[0004] The currently commonly used flexible resistive pressure sensors mainly use composite thin films and porous airgel sensitive structures. Such devices have disadvantages such as weak wide-area detection capability, complex preparation process, high cost, and single electrode structure. The detection range is usually 20kPa. Below, the response to human activities in the higher pressure range of 60-100kPa such as joint bending and foot pedaling is saturated, and it is difficult to achieve comprehensive detection, which restricts its practicality and commercialization

The flexible resistive pressure sensor prepared by combining polyurethane porous sponge and MXene sheet material by impregnation method combines the mechanism of sponge fiber deformation and MXene layer spacing change, and utilizes the large specific surface area, large deformation range and deformation of the porous sponge structure. The characteristics of strong recovery ability can expand the response range to more than 60kPa, and realize the pressure response of a wide range. At the same time, it has the advantages of simple process, low cost, and large range. It provides a new development direction for the research of flexible resistive pressure sensors. For example, patent CN112146795A discloses a pressure sensor based on MXene composite styrene-butadiene rubber sponge, which uses the deformation of the sponge to achieve wide-range detection, but does not carry out package protection and introduce electrode microstructure

Patent CN109830594B discloses a piezoresistive sensor based on acetylene black composite cell structure, using degradable materials starch and Ecoflex, but the sensitivity is low (0.272kPa- 1 ) and the synthesis process of the porous structure is more complex

For electrode microstructure sensitization, the patent CN112179530A discloses a laminated flexible piezoresistive sensor based on graphene composite filter paper and composite fabric, which utilizes the microstructure of the filter paper itself to increase the contact area with the fabric to achieve a structural Stability and high sensitivity in the low pressure range, but the measurement range is not as good as that of composite sponge devices, and the overall linearity is not high, and there is obvious segmental attenuation

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