study of a dual longitudinal and shear acoustic wave ZnO transducer in the gigahertz frequency range: application to viscosity measurement and first step for device integration

In this paper, we study a high frequency (~1GHz) ZnO transducer integrated within a silicon substrate, which generates in the same area, a compressional and a shear acoustic wave. These two kinds of waves can be used to characterize fluid-solid interfaces' properties in the same microscopic area and at the same time from the longitudinal and the shear reflection coefficients [1], [2]. The principle will be explained and validated using RF microprober. With this in mind, the shear and volume viscosity of a drop of water will be presented. Finally, we will propose a first example of electrical matching of the transducer in this high frequency range in order to promote, first, the longitudinal wave.