SENSING LIQUID PROPERTIES WITH THICKNESS-SHEAR MODE RESONATORS

The responses of smooth- and textured-surface thickness-shear mode (TSM) resonators in liquid are examined. Smooth devices, which viscously entrain a layer of contacting liquid, exhibit a response that depends on the product of liquid density and viscosity. Textured-surface devices, which also trap liquid in surface crevices, pores, etc., exhibit an additional response that depends on liquid density alone. Combining smooth- and textured-surface resonators in a monolithic sensor enables the liquid density and viscosity to be extracted simultaneously.