Flexible Pressure Sensor Based on PVA-Cellulose Composite Electrolyte Film

Flexible pressure sensors, as fundamental components of wearable electronic devices, hold significant potential for application in human-machine interfaces, human motion monitoring, and other related fields. In this study, phosphoric acid/urea phosphate solution was utilized as the dissolution system of cellulose to prepare polyvinyl alcohol (PVA)-cellulose composite electrolyte films. Herein, urea phosphate plays a role in stabilizing the dissolved state of cellulose. The effects of cellulose content and baking time on the mechanical and electrical properties of electrolyte films were systematically investigated. Results indicate that the incorporation of cellulose and suitable baking time of 3 ∼ 5h are beneficial to the enhancement of electrolyte properties. Based on the electrolyte films prepared by optimized process conditions, flexible pressure sensors were successfully fabricated. The sensors exhibited rapid response and recovery times of 0.34 s, a minimum detectable pressure of 0.0196 N, high sensitivity of more than 0.27 kPa^-1 and excellent stability. The maximum hysteresis of these sensors was less than 1% FS, highlighting their high precision and reliability.