Effective utilization of acoustic wave sensor responses: simultaneous measurement of velocity and attenuation

When using acoustic wave devices as sensors, responses arise from perturbations in wave-propagation characteristics (velocity and attenuation) caused by wave interactions with a surface layer. Simultaneous measurement of both velocity and attenuation changes helps elucidate the wave-perturbation mechanisms. A number of wave-surface-layer interactions have been investigated involving surface acoustic waves (SAWs) in the gas phase and acoustic plate modes (APMs) in liquids. These include mass loading of a SAW, acoustoelectric interactions between SAWs and a conductive film overlay, mass loading of an APM, and viscous coupling of an APM to an adjacent liquid medium.<
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