Structure design and fabrication of a novel dual-mass resonant output micromechanical gyroscope

Abstract

A novel dual-mass resonant output micromechanical gyroscope is proposed which utilizes resonant sensing as the basis for Coriolis force detection instead of displacement sensing. It can overcome the shortcoming of single-mass resonant output micromechanical gyroscope and can reduce the common mode acceleration error by using a dual-mass topology structure and lever differential mechanism. The structure and operating principle of the device are introduced. Moreover, some important theoretical analyses of the gyroscope are provided in detail. The analytical results have shown that the resonant frequencies of vibrating mass and double-ended tuning fork resonators are 3.153 and 62.853 kHz. The device has a frequency sensitivity of 12.535 Hz/deg/s and a mechanical noise floor of $$ 7.957\deg /{\text{h}}/\sqrt {{\text{Hz}}} $$in air. The finite element simulation results verify the accuracy of analytical algorithms. The common mode acceleration error of device can be reduced by 97.6%. The device is fabricated by SOG (Silicon on Glass) micro fabrication technology. Some important performances are measured by experimental method. The micromechanical gyroscope can be used to estimate the rotation rate by further implementing the signal processing electronics.