Out-of-plane electrode architecture for fused silica micro-glassblown 3-D wineglass resonators

In this paper, we report an out-of-plane electrode architecture for micro-glassblown fused silica wineglass gyroscopes. Transduction is enabled by the 3-D mode shape of the wineglass resonator, which allows one to drive and sense the wineglass modes using the out-of-plane component of the vibratory motion. The transduction architecture has been succesfully demonstrated on fused silica wineglass resonators with Q-factor over 1 million, on both modes, and high frequency symmetry (Δf/f) of 132 ppm at a compact size of 7 mm diameter and center frequency of 105 kHz. Out-of-plane electrode architecture enables the use of sacrifical layers to define the capacitive gaps, which enables wafer-level integration, mitigates alignment issues and provides uniformly small gaps. 10 µm capacitive gaps have been demonstrated on a 7 mm shell, resulting in over 9 pF of active capacitance within the device. Wafer-level scalability of out-of-plane electrode architecture may enable batch-fabrication of high performance fused silica micro-glassblown wineglass gyroscopes at a significantly lower cost than their precision-machined macro-scale counterparts.