Mass Sensitivity Measurements of a Novel High Q-Factor Disk Resonator for Liquid-Phase Sensing Applications

We present, for the first time, mass sensitivity measurements of a novel resonant mode based on a disk resonator that delivers the one of the highest Q-factors among resonators tested in liquid (Q of 362). The mode of interest is referred to as the Button-like (BL) mode as its associated lateral strain profile resembles a shirt button. In the context of mass sensing, the high Q-factor of the BL mode enhances mass resolution. Its motional resistance (R
_m
) in water is 5.3kΩ, which greatly eases the difficulty in designing control circuits. In this paper, we measured the mass sensitivity of the device by depositing chrome (Cr) on the bottom surface of the device through a back cavity. The resonator has a measured mass sensitivity of 17.2ppm/ng for uniformly deposited mass on the resonator's surface.