Patent ID: 8669688

Claim:
A shear-horizontal surface acoustic wave sensor, comprising: a piezoelectric substrate, a unidirectional transmitting interdigital transducer on the substrate that primarily excites shear-horizontal waves on the substrate, a guiding layer on the substrate that has a lower shear velocity than the substrate for confinement of the shear-horizontal wave therein as a guided Love wave, a sensing region on the guiding layer, and a unidirectional receiving interdigital transducer that detects the guided Love wave that is transmitted through the sensing region, wherein the unidirectional transmitting and receiving transducers each comprise at least one cell, each cell comprising excitation and reflection electrode fingers, and wherein the finger spacings are optimized to excite or detect shear-horizontal waves that are in-phase along the length of each transducer in the presence of the guiding layer and the sensing region.