Design and Analysis of a MEMS Comb Vibratory Gyroscope

MEMS (Micro-electro-mechanical Systems) refer to devices or systems integrated with electrical and mechanical components in the scale of microns. Due to its small size, low cost, low power consumption and high efficiency, MEMS technology has been widely used in many fields. In this paper, a novel comb-driven, differential capacitance sensing MEMS vibratory gyroscope based on glass-silicon-glass structure is proposed. The gyroscope is activated to vibrate along X axis by electrostatic comb driving. If an angular velocity along Y axis is experienced, the Coriolis force along Z axis activates the sensing vibration of the central mass along Y axis. The size of the driving beams and sensing beams are carefully chosen to reduce the frequency mismatch in two directions, thus increasing the gyroscope sensitivity. The working principle and dynamic analysis of this gyroscope are given and a set of optimized design parameters are derived based on the analysis. ANSYS FEM simulation is used to find out the device frequency and verify the theoretical prediction. The fabrication process flow of the MEMS gyroscope is also proposed. The microgyroscope can be used for inertial navigation in many applications, such as automobile, aerospaceship, microsatellite, consumer products, etc.