Graphene Oxide Integrated Surface Acoustic Wave Humidity Sensor with Simultaneous Multi-Frequency Operation

Abstract

Humidity is crucial in agriculture, electronic device fabrication, and climate change. In particular, as the coronavirus outbreak globally spreads, airborne water moisture has been considered the carrier of airborne viruses. Therefore, there is much need to develop accurate and precise humidity sensors to predict and prevent coronavirus transmission. This paper presents the multi-frequency surface acoustic wave (SAW) platform with graphene oxide (GO) decoration for humidity sensing. The novel claims include (1) the localized integration of GO with ng-resolution using an electrospray deposition (ESD) system, (2) highly sensitive and stable sensing performances by selecting proper operating resonant frequency depending on relative humidity (RH) levels, and (3) use of the developed sensor for face mask inspection. Our findings suggest that the multi-frequency SAW ensures high measurement sensitivity over a large RH range, further improving the current state of the resonator-based humidity sensors. © 2023 IEEJ.