Out-of-plane axis SOI MEMS gyroscope with initially displaced vertical sensing comb

We developed a capacitive silicon on insulator (SOI) microelectro-mechanical systems (MEMS) tuning-fork gyroscope and describe its structure and performance. The gyroscope is composed of initially displaced vertical sensing combs we developed to sense out-of-plane motion of a proof mass. The initial displacement between the movable electrodes and fixed electrodes of the vertical sensing combs is achieved simply by applying DC bias voltage between the movable sensing proof mass and the handle layer of the SOI wafer. We also employed a one-sided force feedback scheme that is easily fabricated in an SOI and resulted in ±0.5% nonlinearity.