A high sensitive and robust controllable MEMS gyroscope with inherently linear control force using a high performance 2-DOF oscillator

Future markets demand high performance inertial sensors implemented by incorporating a micromachined sensing element in a closed loop controller. There is a nonlinear effect on electrostatic control force for closed loop sensors. Nonlinear control force degrades the closed loop controller performance. This study reports a controllable microgyroscope design concept with the help of a new 2-degrees-of-freedom (2-DOF) sense mode oscillator to linearize the electrostatic control force. However, design of a structure with characteristics including high mechanical gain and high operational frequency without sacrificing electronic sensitivity is serious challenge for 2-DOF dynamical systems. The proposed design can involve these parameters simultaneously in addition to control force linearity. Besides, greater electronic sensitivity is achievable due to ability of selecting secondary mass (sense mass) larger than primary mass. The prototype with an overall size of 0.46 × 0.635 mm is designed to be fabricated in surface micromachining process with 3 μm structural layer thickness. In addition to providing finite element method (FEM) simulation results, the conventional and proposed 2-DOF design performances are compared using MATLAB analysis.