A Single-Electrode, Textile-Based, Flexible Capacitive Pressure Sensor Array

Abstract

Flexible capacitive pressure sensors have been widely developed to be used in electronic skin, human movement, real-time health monitoring, and human–machine interactions. This paper introduces a Flexible Capacitive Pressure Sensor Array (FCPSA) that is designed to reduce costs and can be integrated into commercial textiles, e.g., insoles. The FCPSA comprises a five-layer sandwich structure. The bottom layer is a conductive layer, operating both as interference shielding and the common electrode for the distributed capacitive sensor array, with a polyester double-jersey-knitted fabric acting as the dielectric material, segmented carbon woven fabrics as the top electrodes in the array, a polymeric film for electrical and moisture isolation, and a foam placed on the surface to improve comfort. A system including three CPSs and a data acquisition device is established for real-time pressure monitoring. In the range of 0–100 kPa, a capacity increase of 35% is observed, the linearity of which depends on the elastic behavior of the dielectric layer. This sensor array can be utilized for real-time pressure monitoring.