A novel Love mode SAW sensor with ZnO layer operating in gas and liquid media

Abstract

Novel layered Surface Acoustic Wave (SAW) sensors, based on a Zn0/90" rotated ST-cut quartz crystal structure, were fabricated. They were employed as gravimetric sensors for immunosensing applications and as SAW cunductometric sensors for gas sensing applications. These sensors are able to sense oxygen gas concentrations as low as 0.2 ppm in nitrogen gas. Their mass detection limit in liquid media is as low as 100 pgr/cm'.

Crystalline structure effect on the performance of flexible ZnO/polyimide surface acoustic wave devices

“…As the wavelength is much longer than the thickness of the PE layer, acoustic waves will penetrate deep into the substrate. The phase velocity for the Rayleigh wave in an ideal (0002) ZnO layer is $2650 m/s, 33 which, in thin film cases, is dependent of the film thickness and the crystal quality. Whereas the phase velocity of the polyimide can be estimated by the following equation: 34…”

The characteristics of low-temperature-synthesized ZnS and ZnO nanoparticles

“…Due to higher exciton binding energy of 60 meV, ZnO has more efficient exciton emission at room temperature [7]. It can also be used in surface acoustic wave (SAW) devices [8][9][10] as piezoelectric layer and SAW sensors [11][12].…”

Flexible surface acoustic wave devices and its applications in microfluidics

“…When the wavelength is much larger than the thickness of the PE layer, the acoustic waves would penetrate partially into the substrate; hence the velocity is influenced by the material properties of the substrate. The phase velocity for the Rayleigh wave in (0002) single crystalline ZnO layer is ~2650 ms -1 [19], while that in the polyimide is the function of material's Young's modulus, density. The theoretical Rayleigh wave velocity of the polyimide substrate is 754 ms -1 much smaller than that of ZnO.…”