Electrothermal Driving Microcantilever Resonator as a Platform for Chemical Gas Sensing

In the current research, the use of a micromachined cantilever resonator as a platform for chemical gas sensing was examined. The microcantilever resonator integrates an electrothermal driving unit and a piezoresistive detecting unit, and it is fabricated by direct bonding a silicon-on-insulator (SOI) wafer. With a particular polymer layer coated on the surface of the microcantilever, a gas sensor for volatile organic components (VOCs) detection can be realized. The operation mechanism provides the microcantilever resonator with integrated circuit (IC) compatibility in terms of both the fabrication process and operating voltage. The configuration of the microcantilever resonator can optimize the performance of the gas sensor. The SOI wafer provides a solution for the integrated fabrication of the microstructure, transducers, electronics, and the precise control of the resonator parameters. In this paper, the principles, design, analysis, process, and demonstration of the gas sensor based on the microcantilever resonator are presented. The experimental results provide confirmation that the polymer-coated microcantilever resonator has excellent performance with regard to VOC detection.