Bulk acoustic wave sensors for sensing measurand-induced electrical property changes in solutions.

A variety of quartz thickness shear mode (TSM) resonant sensors with different electrode configurations have been designed, fabricated, and tested in liquids for probing liquid electrical property changes. The resonant frequency of the sensors was found to have more than an order of magnitude increase in sensitivity over the standard AT-cut quartz resonant sensor. The increase in sensitivity is due to the ability of the sensors to detect changes in the electrical properties in the liquid.