A novel bulk micromachined gyroscope based on a rectangular beam-mass structure

Abstract Described in this paper is a micromachined vibratory gyroscope fabricated by combining anisotropic etching and deep reactive ion etching (DRIE) process. The basic structure of the device is a cantilever beam-mass structure. The cross section of the beam is rectangular. The gyroscope employs electrostatic driving and piezoresistive sensing. The gyroscope can operate in an atmospheric pressure environment due to the high quality factor in the sensing direction. Piezoresistive sensing avoids the difficulties caused by small capacitance detection. The packaging and testing costs can be reduced significantly. A novel operation mode of two-dimensional excitation and phase detection for vibratory gyroscopes is also proposed. The gyroscope is measured by both of the amplitude detection and phase detection. Experiment results show that the sensitivity for angular rate signal is about 11.45 μV/°/s/5 V in the range of −120–120°/s in an atmospheric pressure environment when the amplitude detection is used. The phase change is about 0.152°/°/s in the range of −120–120°/s when the phase detection is used.

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