Lorentz force based resonant MEMS magnetic-field sensor with optical readout

A Lorentz force based resonant MEMS magnetic-field sensor with optical readout has been demonstrated. The sensor employs a micromachined resonant mirror that is excited by the Lorentz force generated between a sinusoidal current flowing through a coil on the mirror and the incident magnetic field. The amplitude of the rotation angle is detected by the optical positioning system and external electronics. Sensor sensitivity is controlled by the control of the coil bias current, and shows linear sensitivity with incident field. The resolution and noise floor is 0.4 nT and 1.78 nTi,/root Hz respectively at 53 mHz bandwidth, for a coil bias current of 50 mA(rms) and operation at atmospheric pressure. This sensor is suitable for various applications due to wide measurement range, from sub-nanoTesla fields to several Tesla. (C) 2016 Elsevier B.V. All rights reserved.