Piezoelectric-on-Silicon MEMS Lorentz Force Lateral Field Magnetometers

This paper describes the realization of piezoelectric-on-silicon lateral field Lorentz force magnetometers (LFMs) that target operation in ambient pressure instead of vacuum. Specifically, we describe two device topologies based on the out-of-plane resonant vibration modes. The first is based on a classic cantilever while the other is based on a corner-flapping square plate. In both topologies, piezoelectric transduction is exploited to enhance the sensitivity of the device compared to prevailing approaches to microelectromechanical system (MEMS) LFMs based on capacitive output interfaces. We show that the responsivity of the corner-flapping square plate topology (12026 ppm/T) is 8.5 times higher than a state-of-the-art lateral field LFM based on a capacitive output interface even without relying on vacuum. We here define responsivity as the output sense current per unit magnetic field density normalized over the input excitation current.