UC Irvine

We demonstrate, for the first time, sub-1 Hz frequency symmetry in micro-glassblown wineglass resonators with integrated electrode structures. A new fabrication process based on deep glass dry etching was developed to fabricate micro-wineglasses with self-aligned stem structures and integrated electrodes. The wineglass modes were identified by electrostatic excitation and mapping the velocity of motion along the perimeter using laser Doppler interferometry. A frequency split (Δ f) of 0.15 and 0.2 Hz was demonstrated for n=2 and n=3 wineglass modes, respectively. To verify the repeatability of the results, a total of five devices were tested, three out of five devices showed Δ f<5 Hz. Frequency split stayed below 1 Hz for dc bias voltages up to 100 V, confirming that the low frequency split is attributed to high structural symmetry and not to capacitive tuning. High structural symmetry (< 1 Hz) and atomically smooth surfaces (0.23 nm Sa) of the resonators may enable new classes of high performance 3-D MEMS devices, such as rate-integrating MEMS gyroscopes. © 1992-2012 IEEE.