Non-Piezoelectric Generation and Detection of High-Q Resonances in Acoustic Sensors
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Tagungsband zur Informationstagung Mikroelektronik 06
Acoustic sensing in microsystems is traditionally based on the piezoelectric effect. The principle of mag-netic direct generation of acoustic waves can be applied to resonator microsensors and we show that this excitation mechanism can compete and even outperform standard piezoelectric methods. The advantages of remote excitation, inexpensive fabrication with mass production capabilities of the microsensor compo-nent and a wide variety of possible vibration modes are demonstrated. High-Q silicon membranes, alumi-num plates and quartz resonators excited by planar RF coil setups and strong static magnetic fields are evaluated for operation in the thickness shear mode (TSM). Modeling and FEM simulation has been done to improve the understanding of the sensor principles. Mass loading of these resonators shows Sauerbrey-like frequency shifts similar to piezoelectrically excited Quartz Crystal Microbalance (QCM) sensors.