Z-Axis Micromachined Tuning Fork Gyroscope with Low Air Damping

Minh Nguyen,Hoang Chu,Hung Vu,Nhat Ha,Long Nguyen

doi:10.3390/mi8020042

Abstract

This paper reports on the design and fabrication of a z-axis tuning fork gyroscope which has a freestanding architecture. In order to improve the performance of the tuning fork gyroscope by eliminating the influence of the squeeze-film air damping, the driving and sensing parts of the gyroscope were designed to oscillate in-plane. Furthermore, by removing the substrate underneath the device, the slide-ﬁlm air damping in the gap between the proof masses and the substrate was eliminated. The proposed architecture was analyzed by the finite element method using ANSYS software. The simulated frequencies of the driving and sensing modes were 9.788 and 9.761 kHz, respectively. The gyroscope was fabricated using bulk micromachining technology. The quality factor and sensitivity of the gyroscope operating in atmospheric conditions were measured to be 111.2 and 11.56 mV/°/s, respectively.

Highlights

IntroductionMicro-gyroscopes have the advantages of small size, low cost, and suitability for mass production
Micro-gyroscopes have the advantages of small size, low cost, and suitability for mass production.The micro-gyroscopes can be used in the automotive industry to make anti-rollover systems, antiskid controls, and electronic stability controls [1]
We propose a capacitive-type z-axis tuning fork quality factor of the driving and sensing modes

Summary

Introduction

Micro-gyroscopes have the advantages of small size, low cost, and suitability for mass production. The micro-gyroscopes can be used in the automotive industry to make anti-rollover systems, antiskid controls, and electronic stability controls [1]. The micro-gyroscopes have further applications in robotics and military equipment including inertial navigation for aeronautics and astronautics, and platform stabilization [3]. The tuning fork gyroscope (TFG) with an electrostatic drive and capacitive-type sensing is mostly preferred thanks to its reported potential capabilities and advantages such as common-mode rejection and low power consumption [4,5,6,7,8,9]. In order to achieve higher sensitivity and better rate resolution, the micro-gyroscope needs to be designed with a large sense-mode Q

Methods

Discussion

Conclusion