High-Performance Two-Dimensional MEMS Micro-Magnetic Sensor With Magnetic Circuit Differential

Abstract

Two-dimensional magnetic sensors of soft magnetic film/planar coil laminated have the advantages of low power consumption and high sensitivity, which has great potential in developing miniaturized high-performance magnetic sensors. However, the miniaturization of magnetic sensors increases the noise level resulting in limited detection ability. In this letter, a novel two-dimensional MEMS soft magnetic film/planar coil laminated micro-magnetic sensor with magnetic circuit differential is proposed. Magnetic circuit differential technology effectively reduces the common-mode noise of the micro-magnetic sensor, so the intrinsic noise of the proposed micro-magnetic sensor is significantly suppressed. Moreover, the geometric parameters of the proposed micro-magnetic sensor are optimized by MEMS technology, and the sensitivity is improved. Consequently, the detectivity of the two-dimensional MEMS micro-magnetic sensor with magnetic circuit differential is significantly enhanced. Experimental results show that the two-dimensional MEMS micro-magnetic sensor with magnetic circuit differential has a detection limit of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu $ </tex-math></inline-formula> Oe-level, which presents a good development prospect in the weak magnetic field.