An Electrostatic MEMS Roll-Pitch Rotation Rate Sensor with In-Plane Drive Mode.

Ahmed Khaled,Ridha S Almikhlafi,Majed S Alghamdi,Mostafa Soliman,Nawaf S Aljehani,Ahmed M Salman,Mohamed A E Mahmoud,Yasser M Seddiq,Ibrahim F Alzahem,Radwan M Noor

doi:10.3390/s22030702

Abstract

In this paper, we presented a novel electrostatic Roll/Pitch MEMS gyroscope with in-plane drive mode and out-of-plane sense mode. The proposed structure is developed based on a tuning fork gyroscope with decoupled sense mass on each tine that control the sense out-of-plane frequency. A multi-height deep reactive ion etching (DRIE) fabrication process was utilized to achieve and enhance decoupling between the drive and sense modes. We presented our design methodology followed by an analytical and finite element (FEM) model. Our experimental results showed a good match between the analytical model and those obtained experimentally, from the drive and sense oscillation frequencies. Our characterization setup used a custom made application specific integrated circuit (ASIC) for characterization and was able to achieve ARW of 0.2 deg/rt-h, a bias instability 5.5 deg/h, and scale factor non-linearity (SFNL) 156 ppm FS.

Highlights

Multiple axes Micro Electro-Mechanical Systems (MEMS) gyroscopes have dominated the consumer electronics market due to their small size, low cost and fast startup time.Most of these sensors can measure rotation rate in multiple directions using a single mechanical element which yields miniaturized and compact sensors
We present a Roll/Pitch MEMS gyroscope design with in-plane drive mode and out-of-plane sense mode
The application specific integrated circuit (ASIC) considers the MEMS gyroscope as a capacitor with variable capacitance

Summary

Introduction

Multiple axes Micro Electro-Mechanical Systems (MEMS) gyroscopes have dominated the consumer electronics market due to their small size, low cost and fast startup time. Most of these sensors can measure rotation rate in multiple directions using a single mechanical element which yields miniaturized and compact sensors. This approach compromises the multiple axes gyro performance and limits it to consumer applications [1,2,3,4]. These approaches ranges from discrete assembly of high performance individual gyro sensors [5,6,7,8], to folded 3D

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Conclusion