Capacitive and Resistive Humidity Sensors Based on Flexible Nanocellulose Film for Wearable Electronics

Abstract

The paper describes methods for obtaining nanocellulose from miscanthus stalks in an environmentally friendly way using the hydrolysis method. The nanocellulose parameters were investigated for applying the nanocellulose in capacitive and resistive humidity sensors. The influence of electrode system parameters and the operating frequency on sensor characteristics was investigated. It was established that the device sensitivity increases with the reduction of distance between electrodes and the operating frequency. Two models of sorption processes at the gas–solid interface were applied, namely, the Freundlich isotherm and Langmuir isotherm, for describing the mechanism of water adsorption by nanocellulose-based humidity sensors. The long-term operation stability of such devices was also investigated.