Dual-axis Lorentz Force MEMS Magnetometer

Abstract

This paper presents a dual axis MEMS magnetometer, utilizing two DOF torsional gyroscope structure. The designed structure is a torsional resonator with two gimbals. A single structure can detect magnetic field in two directions. The first and second mode of vibrations are the desired mode of operation for detecting the magnetic field in x and y directions. The first and second modes of vibrations are at 107 kHz and 187 kHz respectively. The device is tested for its Lorentz force transduction using MSA-500 in the presence of magnetic field generated using permanent magnet for both the axes at atmospheric pressure. The fabrication process is based on anodic bonding (<; 400°C) of a borofloat glass wafer and double side polished (DSP) Si wafer, which enables the passivation between Gold loop and Silicon.