Fused Silica Micro Shell Resonator With T-Shape Masses for Gyroscopic Application

Abstract

This paper presents a novel micro shell resonator (MSR) with T-shape masses based on fused silica using out-of-plane electrode structures. Eight circular-distributed T-shape masses are designed along the rim of resonator shell to improve transduction efficiency, including drive efficiency and detection efficiency. The dynamic parameters and transduction efficiency are calculated and optimized with finite element method, revealing 3.76 times improvement in drive efficiency, 4.65 times improvement in detection efficiency, and 17.81 times increase in mechanical sensitivity. In addition, it is feasible to trim the frequency by adding or removing mass on the T-shape masses. The key feature of the process is based on micro blow-torching process and whirling platform, which form the resonator structure with smooth roughness and good structure uniformity. Femtosecond laser ablation is used to release the T-shape masses for good symmetry and high processing quality. Then, metalized MSR with T-shape masses is assembled on a glass substrate. Electrostatic transduction is used to detect spatial deformation of resonators by out-of-plane electrodes, which reveals a frequency mismatch of 0.175% at 6904.4 Hz and 6916.5 Hz with quality factors of 20.39 k ( $\tau =0.94$ s) and $Q = 36.94$ k ( $\tau =1.7\text{s}$ ). [2017-0086]