Acoustic interference suppression of quartz crystal microbalance sensor arrays utilizing phononic crystals

Acoustic interference suppression of quartz crystal microbalance (QCM) sensor arrays utilizing phononic crystals is investigated in this paper. A square-lattice phononic crystal structure is designed to have a complete band gap covering the QCMs resonance frequency. The monolithic sensor array consisting of two QCMs separated by phononic crystals is fabricated by micromachining processes. As a result, 12 rows of phononic crystals with band gap boost insertion loss between the two QCMs by 20 dB and also reduce spurious modes. Accordingly, the phononic crystal is verified to be capable of suppressing the acoustic interference between adjacent QCMs in a sensor array.