Aqueous Transduction of Poly-Sige Disk Resonators

This paper demonstrates an electrostatic transducer for lateral contour-mode resonators in which the transduction gaps are filled with a liquid dielectric (water) having much higher permittivity than air ( kappa_water = 80.1). Aqueous transduction is more efficient than air-gap transduction (lower motional impedance) and has a higher frequency tuning range compared than solid-dielectric transduction. We have demonstrated a 42 MHz poly-SiGe disk resonator with de-ionized (Dl) water confined to the electrode gaps. The resonator has a measured quality factor (Q) of 3,800, motional impedance (Rx) of 3.9 kOmega and 3% series frequency tuning range.