Liquid operating TPoS MEMS resonators with high quality factor

In this work, we proposed a liquid operating TPoS MEMS resonators with on-chip dummy resonator patterns. The fabricated plate type resonators achieve high Q factors in length extensional mode under vacuum, air and liquid environment. With the proposed on-chip dummy resonator patterns, the anti-resonance peak near the resonant frequency was effectively cancelled and Q factors were improved. A resonator with 400 μm and 600 μm plate length shows a Q factor of 10,072 and 14,435, respectively, under 1.0 mTorr. Q factors in liquid phase were measured 71 and 98 in Ethanol, respectively. It was also confirmed that the Q factors in liquid phase varied with the types of liquids (according to their viscosity and density).