<title>Force-balanced dual-axis microgyroscope</title>

Abstract

ABSTRACT The surface micromachining process realized the dual-axis microgyroscope. The 7.5 p rn-thick polysilicon layerdeposited by LPCVD is used for the vibrating structure. In this research, we present a new structure with high angular inertiarnomentum and compact size. In particular, this structure can utilize a simple force-balancing torsional torque which doesnot need another top electrode layer to reduce the intrinsic non-linearity of a capacitive-type sensor. The gyroscope is testedin a high vacuum chamber for a high Q-factor. The sensing mode is separated 2% from the driving mode by applying theinter-plate DC tuning bias. The experiment resulted in a noise equivalent signal of 0.1 deg/sec. 1. INTRODUCTION Gyroscope devices for measuring the angular rate have been the subject of extensive research and development over thepast several decades. There has been an increasing attention to the development of a low cost and small size gyroscope sincethere exist a lot of applications for such devices'4. Among recent works, a dual-axis gyroscope57 occupying smaller spaceand costing less than two uni-axis gyroscopes with orthogonal configuration has been presented. In addition, for widerpotential applications from consumer electronics to military, a large dynamic range of angular rates should be sensed.Several works reported the potential capabilities and advantages of a force-balanced microgyroscope6'12. This paper reports anew dual-axis microgyroscope with a simple force-balancing capability.