Remote Electromagnetic Excitation of High-Q Silicon Resonator Sensors

Abstract

The excitation of acoustic resonators is traditionally based on the piezoelectric effect. The alternative magnetic direct generation of acoustic waves is the basic operation principle of electromagnetic acoustic transducers (EMATs). For sensor applications this method can be applied to a mechanical resonator, thus enhancing the rather poor transduction efficiency by the high acoustic Q-factors. This principle has been theoretically investigated in FEM and PSpice simulations and practically applied to high-Q silicon membranes. The advantages of this non-piezoelectric sensor showing strong resonances with Q-factors up to 105 have been demonstrated. Sensor response to mass loading shows a Sauerbrey-like behavior suitable for sensing purposes