Inkjet-Printed Capacitive Micromachined Ultrasonic Transducer (CMUT) for Moisture Sensing

Abstract

This study presents a miniaturized CMUT- based moisture sensor that is functionalized by the inkjet printing technique. The multi-cell CMUT designed in a hexagonal cell arrangement was fabricated. A graphene oxide sensing film was inkjet-printed on the surface of the CMUT for adsorption of water molecules. The sensitivity, repeatability, and hysteresis characteristics of the moisture sensor were tested. The inkjet-printed CMUT showed a significantly reduced hysteresis level than our previous drop- casted devices.