Contactless Time-Gated Technique for Electromagnetic Interrogation of Micromechanical Resonator Sensors

A technique for the electromagnetic contactless interrogation of entirely passive micromechanical resonant sensors is presented. The principle is based on periodical interleaved excitation and detection phases, exploiting the transient response of the resonator. A lumped-element equivalent circuit has been studied in order to model the interrogation principle. The successful implementation on a MEMS SOI microcantilever resonator sensor operating at 10.186 kHz demonstrates the effectiveness of the proposed interrogation principle working on a distance of about 1 cm.