However it should be noted that sensitivity is also a function of electrode type, number of fingers, width and pitch of finger, delay path length and substrate selection. application of the ZnO-glass structure Love wave sensors intended for the detection of liquid properties, such as viscosity, density and mass anchored to the sensor surface. Keywords: Love modes, viscosity, mass density, sensitivity, wave attenuation, wave velocity, ZnO, glass, biosensor, liquid environment, Rayleigh wave == 1 . Introduction == Love waves are acoustic modes that propagate along the surface of a structure comprising a layer on top of a half-space, when the shear bulk acoustic wave velocity of the layer is slower than that of the substrate. The difference between the mechanical properties of the layer and the substrate results in an entrapment of the acoustic energy in the guiding layer. The Love waves are shear horizontally polarized normally to the wave propagation direction. The shear polarization and the guiding layer effect make the Love wave sensors suitable for liquid application and very sensitive to any changes occurring on their surface, such as those related to mass loading and changes of the liquid viscosity and density [1, 2, a few, 4, 5]. At the guiding layer surface, the liquid is sheared and shear waves in the liquid are set up. Due to the attenuation of shear waves in viscous liquids, the energy is dissipated rapidly and the shear waves do not penetrate far into the liquid. The Love mode velocity is reduced and the attenuation is increased along its propagation path due to energy lost in shearing the fluid: the resulting velocity change and the attenuation depend on the viscosity of the fluid as well as on the guiding layer thickness. Piezoelectric wurtzite ZnO thin film technology has been widely used for many years for the fabrication of surface acoustic wave (SAW) devices onto non piezoelectric substrates, such as silicon, glass, and sapphire, to name just a few. When the hexagonal ZnO film has its c-axis orthogonal or Bovinic acid parallel to the substrate free surface, it is effective in the transduction of Rayleigh waves or Love waves: the electric field is coupled to Rayleigh waves in the former case, and to Love waves in the latter. When the piezoelectric film has its c-axis tilted at an angle with respect to the normal to the substrate surface, intended for wave propagation along the <100> direction, two types of surface modes propagate: the Love-like, with predominant in-plane shear horizontal polarization, and the Rayleigh-like, with a prevailing sagittal polarization. Both the two modes are coupled to the electric field via the effective piezoelectric constants of the film. Thus, Love wave devices can be directly fabricated on silicon or glass substrate by using the thin piezoelectric film technology whose characteristics depend on the piezoelectric guiding layer thickness and on the c-axis tilt angle. Depending on the materials crystallographic orientation, both the in-plane polarized Love mode and the out-of-plane polarized surface acoustic waves (SAWs) can be excited on the same Bovinic acid multilayered structure. The Love mode and the SAW play two different roles in the same sensing platform: the former is suitable for liquid environment characterization, while the latter is suitable for mixing and pumping small liquid volumes. Matatagui et al. reported the development of a Love wave immunosensor with microfluidic technology to detect potentially pathogenic microorganisms in real time [6]. Most Love mode sensors are implemented on quartz covered by a SiO2guiding layer, but Love mode sensors implemented on Bovinic acid silicon or glass substrate materials offer the great advantage of the sensors integration with the surrounding electronic circuits [7]. In this paper, we theoretically investigate the performance of a ELTD1 glass/ZnO Love wave sensor which is suitable for the fabrication of a biological sensing platform including Rayleigh wave-based microfluidic devices. The organization of the present article begins with a study of the mass sensitivity of a two-layer model, a lossless glass substrate covered by a 30 tilted c-axis ZnO guiding layer, in vacuum..