title: A z-axis quartz cross-fork micromachined gyroscope based on shear stress detection.
abstract: Here we propose a novel quartz micromachined gyroscope. The sensor has a simple cross-fork structure in the x-y plane of quartz crystal. Shear stress rather than normal stress is utilized to sense Coriolis' force generated by the input angular rate signal. Compared to traditional quartz gyroscopes, which have two separate sense electrodes on each sidewall, there is only one electrode on each sidewall of the sense beam. As a result, the fabrication of the electrodes is simplified and the structure can be easily miniaturized. In order to increase sensitivity, a pair of proof masses is attached to the ends of the drive beam, and the sense beam has a tapered design. The structure is etched from a z-cut quartz wafer and the electrodes are realized by direct evaporation using the aperture mask method. The drive mode frequency of the prototype is 13.38 kHz, and the quality factor is approximately 1,000 in air. Therefore, the gyroscope can work properly without a vacuum package. The measurement ability of the shear stress detection design scheme is validated by the Coriolis' force test. The performance of the sensor is characterized on a precision rate table using a specially designed readout circuit. The experimentally obtained scale factor is 1.45 mV/°/s and the nonlinearity is 3.6% in range of ± 200 °/s.
authors.affiliation: College of Mechatronics Engineering and Automation, National University of Defense Technology, Changsha, 410073, Hunan Province, China. nudtxie@yahoo.com.cn
authors.forename: Liqiang
authors.initials: L
authors.lastname: Xie
authors.forename: Xuezhong
authors.initials: X
authors.lastname: Wu
authors.forename: Shengyi
authors.initials: S
authors.lastname: Li
authors.forename: Haoxu
authors.initials: H
authors.lastname: Wang
authors.forename: Jianbin
authors.initials: J
authors.lastname: Su
authors.forename: Peitao
authors.initials: P
authors.lastname: Dong
mesh_terms: D003312:Coriolis Force; D004566:Electrodes; D004867:Equipment Design; D055616:Microtechnology / Q000295:instrumentation* / Q000379:methods; D011791:Quartz / Q000737:chemistry*; D012399:Rotation; D013314:Stress, Mechanical
chemical_list: D011791:Quartz