1 Million Q-factor Demonstrated on Micro-glassblown Fused Silica Wineglass Resonators with Out-of-plane Electrostatic Transduction

In this paper, for the first time, we report Q-factor over 1 million, on both modes, and high frequency symmetry (∆f/f ) of 132 ppm on wafer-level micro-glassblown 3-D fused silica wineglass resonators at a compact size of 7 mm diameter and center frequency of 105 kHz. In addition, we demonstrate for the first time, out-ofplane capacitive transduction on MEMS wineglass resonators. High Q-factor is enabled by a high aspect ratio, self-aligned glassblown stem structure, careful surface treatment of the perimeter area, and low internal loss fused silica material. Electrostatic transduction is enabled by detecting the spatial deformation of the 3-D wineglass structure using a new out-of-plane electrode architecture. To the best of our knowledge, work presented in this paper is the highest reported Q-factor on a degenerate mode device at 7 mm diameter or smaller. Micro-glassblowing may enable batch-fabrication of high performance fused silica wineglass gyroscopes at a significantly lower cost than their precision-machined macro-scale counterparts.