Lithium tantalate layer guided plate mode sensors

Wafers of lithium tantalate have been lapped and polished prior to the fabrication of interdigital transducers (IDT). The effect of building up successive polymer layers is reported for both the surface containing the IDT and the opposite face. The data demonstrates the ability of lithium tantalate to support layer guided plate mode; such acoustic wave sensors allow fabrication of the transducers on the opposite face to the sensing surface. In addition, the sensitivity to thin gold films deposited on the guiding layers both on the IDT and opposite faces is reported.