A Novel High Transduction Efficiency Micro Shell Resonator Gyroscope With 16 T-Shape Masses Using Out-of-Plane Electrodes

A novel micro shell resonator gyroscope (MSRG) with 16 T-shape masses using out-of-plane electrodes is proposed in this paper. The T-shape masses are designed for high transduction efficiency. Out-of-plane electrodes are used to drive and detect the spatial deformation of the resonator. The finite element method (FEM) is applied to evaluate the influence of the T-shape mass on transduction efficiency. Compared with the MSRG without the T-shape masses, the FEM results reveal that the MSRG with T-shape masses has shown an increase of 42% on effective mass (<inline-formula> <tex-math notation="LaTeX">${M}_{ {eff}}$ </tex-math></inline-formula>) and a decrease of 8% on <inline-formula> <tex-math notation="LaTeX">${f}_{ {n=2}}$ </tex-math></inline-formula>. For the MSRG without T-shape mass, spherical–cylindrical, spherical, and out-of-plane electrodes have been applied to drive and sense n = 2 wineglass modes. Compared with the MSRG without T-shape using out-of-plane electrodes, the MSRG with T-shape masses has showed the improvement of 334%, 522%, and 598% on driving efficiency (<inline-formula> <tex-math notation="LaTeX">${S}_{ {d}}$ </tex-math></inline-formula>), detection efficiency (<inline-formula> <tex-math notation="LaTeX">${S}_{ {s}}$ </tex-math></inline-formula>), and mechanical sensitivity (<inline-formula> <tex-math notation="LaTeX">${S}_{ {mech}}$ </tex-math></inline-formula>) due to large <inline-formula> <tex-math notation="LaTeX">${M}_{\text {eff}}$ </tex-math></inline-formula> and electrode area. In addition, the improvement of 15% in the thermal noise of a gyroscope (ARW<inline-formula> <tex-math notation="LaTeX">$_{\text {mech}}$ </tex-math></inline-formula>) is dominated by a large effective mass, contributing to the improvement of signal-to-noise ratio. The process of micro blow torching with the whirling platform and femtosecond ablation is presented to fabricate the MSRG with T-shape masses. The performance of MSRG is demonstrated experimentally with out-of-plane capacitive transduction. The MSRG is operated in the force-rebalance mode, which demonstrates a scale factor of 0.107V/(°/s), an angle random walk of 0.099°/<inline-formula> <tex-math notation="LaTeX">$\text{h}^{{1/2}}$ </tex-math></inline-formula>, and a bias instability of 0.46°/h, showing a great potential for high-performance gyroscopic application.

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