Resonator-Based Bidirectional Lorentz Force Magnetic Sensor

Abstract

We present a low power high sensitive in-plane resonant bidirectional Lorentz-force magnetic micro-sensor operating in air at ambient pressure. The concept is based on the detection of the resonance frequency shift of an electrothermally straight micro-beam resonator operated near the buckling point. Powered at 20 μW, the micro-sensor shows a measured sensitivity (S) of 3.32/(mA.T), which is very high compared to the state of the art. The proposed method is simple in design making it promising for achieving practical low-cost magnetometer.