Identification of ion species in electrolytic solutions using surface acoustic wave liquid flow sensing system based on new pattern recognition method

The surface acoustic wave (SAW) on 36YX LiTaO₃, the shear-horizontal mode (SH-SAW), can detect liquid properties. This paper describes the new method to identify and estimate components and concentration of ions in aqueous solutions by using a liquid-flow sensing system with the SH-SAW sensor without any selective organic films. The principle of the identification is based on the difference in transient responses. The proposed method includes a new technique for constituting the database of mixing ion solution from that of the single ion solutions.