In-Plane Vibration of Hammerhead Resonators for Chemical Sensing Applications.

Abstract

Thermally excited and piezoresistively detected in-plane cantilever resonators have been previously demonstrated for gas and liquid-phase chemical and biosensing applications. In this work, the hammerhead resonator geometry, consisting of a canti-lever beam supporting a wider semicircular head , vibrating in an in-plane vibration mode, is shown to be particularly effec-tive for gas-phase sensing with estimated limits of detection in the sub-ppm (parts per million) range for volatile organic compounds. The paper discusses the hammerhead resonator design and the particular advantages of the hammerhead geome-try, while also presenting mechanical characterization, optical characterization, and chemical sensing results. These data high-light the distinct advantages of the hammerhead geometry over other cantilever designs.