A Resonant Magnetometer Based on MEMS

In this paper, a MEMS surface resonant magnetometer based on Lorentz force is presented. This magnetometer has three current carriers to sense the magnetic field and changes into deflection of beams which will be detected by the comb-capacitance. The alternating current carried by oscillate beams has the same frequency as resonant frequency of the magnetometer structure to make the deflection magnified Q (Quality-factor) times, therefore, it becomes more easily to measure. The mechanical model of the sensitive element was established. The equations of stiffness of the system, deflection, first-order resonance frequency and sensitivity were setup and simulated in ANSYS. The manufactured chip and pictures of its micro structures are presented, as well as the drive and measurement circuit.