Abstract
The design, analysis, and simulation of a new Micro-electromechanical System (MEMS) gyroscope based on differential tunneling magnetoresistance sensing are presented in this paper. The device is driven by electrostatic force, whereas the Coriolis displacements are transferred to intensity variations of magnetic fields, further detected by the Tunneling Magnetoresistance units. The magnetic fields are generated by a pair of two-layer planar multi-turn copper coils that are coated on the backs of the inner masses. Together with the dual-mass structure of proposed tuning fork gyroscope, a two-stage differential detection is formed, thereby enabling rejection of mechanical and magnetic common-mode errors concurrently. The overall conception is described followed by detailed analyses of proposed micro-gyroscope and rectangle coil. Subsequently, the FEM simulations are implemented to determine the mechanical and magnetic characteristics of the device separately. The results demonstrate that the micro-gyroscope has a mechanical sensitivity of 1.754 nm/°/s, and the micro-coil has a maximum sensitivity of 41.38 mOe/µm. When the detection height of Tunneling Magnetoresistance unit is set as 60 µm, the proposed device exhibits a voltage-angular velocity sensitivity of 0.131 mV/°/s with a noise floor of 7.713 × 10−6°/s/ in the absence of any external amplification.
Highlights
Through decades of development, the Micro-electromechanical System (MEMS) gyroscopes for rotation sensing have grown into an indispensable component of civil and military applications, such as consumer electronics, industrial robots, automobiles, and navigation systems [1,2]
The upper layer of mechanical sensing structure is a typical tuning fork gyroscope (TFG), which allows for the differential detection of angular velocity due to the dual-mass design [26]
In comparison with choosing maximum point with a sensitivity of 27.7 mOe/μm, the differential detection enhances the sensitivity by 1.49 times, and enables the rejection of the common-mode errors causing by Tunneling Magnetoresistance (TMR) sensors concurrently
Summary
The Micro-electromechanical System (MEMS) gyroscopes for rotation sensing have grown into an indispensable component of civil and military applications, such as consumer electronics, industrial robots, automobiles, and navigation systems [1,2]. Literatures [17,21] proposed a TMR-based MEMS accelerometer using three-dimensional (3D)-print and micromachined sensing structures respectively Both of them adopted an integrated TMR sensor to detect the position change of the permanent magnet, further recognizing the input acceleration. The constructions of existing TMR-based sensors involve the design of TMR structure and force-deformation conversion mechanism, as well as how to incorporate them to a whole When it comes to inertial devices, most of above accelerometers and gyroscopes adopt magnetic film or permanent magnet to generate magnetic field; it is not conducive to the high integration and mass fabrication. In gyroscopes, the Coriolis displacement of which is so week that is overwhelmed by external noise and crosstalk from drive mode Technologies, such as micro-coil and differential detection, could be taken into account for improving the integration and performances of current designs. The conclusion and concentration of future work are given Section 4
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
