Design and robustness analysis of structurally decoupled 3-DoF MEMS gyroscope in the presence of worst-case process tolerances

This paper presents design of a structurally decoupled 3-DoF non-resonant MEMS gyroscope with increased robustness and gain. The proposed design utilizes dynamic amplification in 2-DoF drive mode oscillator to achieve large gain. The device performance is verified through behavioral model simulations considering the fabrication limitations of standard electroplated nickel micromachining process, MetalMUMPs, of 20 μm structural layer thickness. A wide operational bandwidth of 1.74 kHz with dynamically amplified again of 0.2 μm is achieved at low actuation voltages. A design sensitivity and Monte Carlo analysis is carried out to show the robustness of the design, without any feedback control, within the fabrication process tolerances. Moreover to verify the device performance under the application of angular velocity, a rate table characterization is carried out which resulted in sense mass displacement of 30 nm corresponding to the rotation induced Coriolis force at actuation voltage of 20 V_acV_{ac} and 30 V_dcV_{dc} with angular rotation of 50 rad/s. Behavioral model simulations proved to be an cost-effective and time-saving alternative to the traditional iterative fabrications and physical level simulations.