Fabrication of a flexible capacitor sensor with surface-fabric-structured conductive silicon rubber

Abstract

With the development of electronic technology, wearable electronic products and electronic skin have become the emerging products in this world. In this study, two kinds of flexible plate capacitors were prepared by an optimized spraying process, whose electrode layers and dielectric layers were conductive silicon rubber and pure PDMS, respectively. The inner surface structure of the capacitors was fabricated with the aids of fabric backup. Initial capacitance and capacitance response of sensors with/without fabric surface structure were calculated and analyzed according to formulae of equivalent dielectric constant of composite dielectric layers and equivalent capacitance of the capacitor. Capacitance responses of the sensors to compressive pressure and tensile strain loads were further tested. In addition, the effect of spraying parameters, including spraying distance, plate area and resistance of the CSR with loads were evaluated on the response. The sprayed flexible capacitors were finally demonstrated its potential application in sensing field, such as water dropping, feet lifting and walking. Results indicate that the surface fabric structure of flexible sensors will improve its stability and sensitivity, which assure the sensors of a prospect of motion sensor.