Phononic crystal sensor-demultiplexer for detection of benzene isomers

We have proposed a phononic crystal demultiplexer to distinguish three benzene isomers (p-xylene, m-xylene and o-xylene) from each other. It is obvious that the benzene series are so harmful materials for human body health; so, the proposed sensor could be applicable. The sensor structure consists of periodic tungsten rods in an aluminum host. In order to achieve the sensing purposes, the final phononic structure includes two parallel cavities which target materials are embedded in them. These parallel cavities act as quasi-Mach-Zehnder structure and have been used as acoustic wave resonators. In order to design the demultiplexer part of the structure, each branch was separately designed, then designed branches were assembled together in the form of a demultiplexer. Consequently, the peak frequencies of 189.5 kHz, 192 kHz, and 193 kHz for the mentioned isomers of benzene could be detected from relevant demultiplexer outputs. In this study, the finite element numerical method is used to analyze the acoustic wave propagation through the structure.