A combined comb / bulk mode gyroscope structure for enhanced sensitivity

Abstract

This work introduces a novel dodecagon bulk mode gyroscope structure with parallel plate comb drives. A major contribution, compared to prior art, is that adding combs connected to the central disk structure, at the points of maximum vibration amplitudes, increases the drive strength and results in significant improvement in sensitivity. This can enable the fabrication of high performance bulk-mode gyroscopes in standard commercial MEMS technologies. Prototypes were measured to operate at frequencies of ~1.5 MHz, with quality factors of ~33,000, at a 10 mTorr vacuum level. Preliminary measurements using discrete electronics show a rate sensitivity of 0.31 μV/°/sec, corresponding to a capacitance sensitivity of 0.43 aF/°/sec/electrode.