Highly-Sensitive MEMS Micro-Fluxgate Magnetometer
Ziwei Wang, Ying Shen, Chong Lei, Jiazeng Wang, Shuxiang Zhao, Jiamin Chen, Zhaoqiang Chu, Junqi Gao
Abstract
Fluxgate magnetometers have been widely applied in many fields, such as magnetic anomaly detection, e-compass, etc. In this work, a micro-fluxgate magnetometer based on the implementation of the MEMS technology is proposed. The core of the fluxgate was fabricated by using an amorphous Co-based magnetic material, which shows a good degree of linearity below 0.5 Oe. Moreover, a mixed-signal lock-in circuit was designed to drive and capture signals. Magnetic noise density of such a device was limited to the value of 500 pT/ <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\surd $ </tex-math></inline-formula> Hz at 1 Hz, while the capability of sensing a DC magnetic field of 6 nT was demonstrated, which presents a good development prospect in the weak signal detection domain.