A Liquid-Phase Sensor Using Shear Horizontal Surface Acoustic Wave Devices

摘要

A surface acoustic wave (SAW) is perturbed due to physical and/or chemical changes in an adjacent medium. If a liquid-phase sensor is to be realized, a shear horizontal SAW (SH-SAW) must be used. SH-SAW sensors have been investigated since 1987. Objects measured using an SH-SAW sensor include not only immunoreactions but also liquid properties. The advantage of an SH-SAW sensor is the simultaneous detection of the mechanical and electrical properties of liquids. In this paper, first, the theory behind the SH-SAW sensor is described. Then experimental results using the SH-SAW sensor on 36YX-LiTaO_3 are introduced. In addition, the sensor sensitivities of the SH-SAW sensors that have been fabricated on piezoelectric substrates are theoretically compared.