Separate determination of liquid density and viscosity with sagittally corrugated Love-mode sensors

A novel microacoustic sensor is reported for separate determination of liqu id density and viscosity. The device is based on a layered quartz/SiO2-syst em with sagittal corrugations, supporting acoustic waveguide Love-modes. Th e sensor combines the merits of Love-mode devices, e.g., robustness and hig h sensitivity, with liquid trapping as an effective approach to separate de nsity and viscosity influences on acoustic shear modes. The outstanding fea tures are extraordinary high and adjustable sensitivity to density changes with inherent large differences between density and viscosity responses. A model is discussed to describe the frequency response to liquid loading; Fu rthermore, studies of attenuation changes have shown that only little extra damping occurs due to the corrugations. Moreover, strategies are discussed for device optimisation in terms of temperature stability and sensitivity enhancement. (C) 1999 Elsevier Science S.A. All rights reserved.