SAW Based Phononic Crystal Liquid Sensor with Integrated Periodic Microfluidic Channels

摘要

Phononic crystal sensors that have been developed in the last years proof being a promising sensor platform for different applications as liquid sensors. It has been already shown that the transmission spectrum of phononic structures depends on properties of liquids confined within a crystal. In comparison to known established sensor approaches, where sensors respond to near surface effects such as mass load, the distinguishing feature of proposed solutions is confining the liquid in resonant cavities of the phononic structure allowing determination of volumetric (bulk) properties of the liquid. Current contribution presents technological and experimental results of the surface acoustic wave (SAW) based phononic crystal liquid sensor research. The presented sensor concept integrates an array of periodical microfluidic channels into the SAW platform. Theoretical predictions underline strong demands regarding tolerances of phononic structure dimensions. As a result, the technological process of the sensor manufacturing had to be redesigned in a certain manner. Achieved results, technological challenges and solutions are described in current work.