A Lateral-Axis Microelectromechanical Tuning-Fork Gyroscope With Decoupled Comb Drive Operating at Atmospheric Pressure

TitleA Lateral-Axis Microelectromechanical Tuning-Fork Gyroscope With Decoupled Comb Drive Operating at Atmospheric Pressure
Publication TypeJournal Article
Year of Publication2010
AuthorsGuo, Z. Yang, L. Tao Lin, Q. Cheng Zhao, Z. Chuan Yang, H. Xie, and G. Zhen Yan
JournalJournal of Microelectromechanical Systems
Volume19
Issue3
Pagination458 - 468
Date Published06/2010
ISSN1941-0158
KeywordsDecoupling, gyroscopes, lateral-axis gyroscopes, microelectromechanical systems (MEMS), out-of-plane motion sensing, tuning-fork gyroscopes (TFGs).
Abstract

In this paper, a silicon bulk micromachined lateral-axis tuning-fork gyroscope (TFG) with a decoupled comb drive and torsional sensing comb capacitors is presented. The novel driving comb capacitors are used to suppress the parasitic out-of-plane electrostatic force and, hence, can decouple the mechanical crosstalk from the sensing mode to the driving mode in a simple manner. The torsional sensing combs are designed to differentially sense the out-of-plane rotational moment and are arranged centroidally to be immune to fabrication imperfections for good linearity and electrostatic force balancing. The torsional sensing combs adopted in the TFG help to lower the air damping of the sensing mode while the driving mode of the gyroscope is dominated by slide-film air damping; hence, it can work even at atmospheric pressure. The process for this lateral-axis gyroscope can also be used to fabricate z-axis gyroscopes; therefore, low-cost miniature monolithic inertial measurement units can be realized without vacuum packaging. The TFG is tested at atmospheric pressure with a sensitivity of 17.8 mV/°/s and a nonlinearity of 0.6% in a full-scale range of 1000°/s. The bias stability is measured to be 0.05°/s (1 ¿) in 30 min with an equivalent noise angular rate of 0.02°/s/Hz1/2.

URLhttp://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=5454418&tag=1
DOI10.1109/JMEMS.2010.2046477
Short TitleJ. Microelectromech. Syst.