A Novel Design of MEMS Gyroscope with Control Capability

High performance MEMS gyroscopes can be implemented by embedding in a closed loop controller. For these gyroscopes, the electrostatic controlled force on the proofmass is inherently nonlinear. This study reports a MEMS gyroscope with control capability in which comb driveelectrodes are employed as the controlling mechanism tolinearize the electrostatic controlled force. To avoid interaction of drive and control comb drive electrodes, another mass hasbeen added to the structure. Consequently, proposed gyroscope consists of a 2-DOF sense mode oscillator and a 1-DOF drivemode oscillator. The prototype with an overall size of 0.46 × 0.635 mm is designed to be fabricated in surfaceMicromachining process with 3 μm structural layer thickness.The device operation has verified by Finite Element Method simulations showing a raw mechanical sensitivity of 32 nm fordrive direction oscillation amplitude of 120 nm and angular rotation of 50 [◦/s].

Keywords:

MEMS gyroscope , closed loop controller , delta sigma modulator , 2-DOF oscillator