Micromachined bar-structure gyroscope with high Q-factors for both driving and sensing mode at atmospheric pressure

In this paper, we report the design and fabrication of a novel micromachined electro-magnetically driven fork tuning type gyroscope with bar-structure working at atmospheric pressure. Instead of common squeeze film damping, slide film damping effect plays an important role in this sensor, which enables it to achieve high Q-factors for both driving and sensing mode at atmospheric pressure. The angular rate is sensed by detecting the differential change of capacitance between the bar structures electrodes and the fixed interdigitated electrodes on the glass substrate. The measured Q-factors at atmospheric pressure are 1005 for driving mode and 365 for sensing mode, respectively. The sensitivity of the sensor is about 10mV//spl deg/ /S, and the nonlinearity is less than 0.5%.