New liquid sensor based on one-dimensional phononic crystal

Phononic band gaps structures are periodic composite materials whose elastic properties are modulated spatially. Indeed, multilayer structures provide a new class of sensors. When these structures are used as sensors, their behavior to ultrasound waves depends on the variations of the liquid parameters. These changes can be detected by measuring an isolated transmission peak inside the band gap. Throughout this paper, we perform a theoretical study of a 1Dphononic crystal which formed by stacking of N bi-layers of Steel/PVC. Using transfer matrix method (TMM), the results clearly demonstrates that the calculated transmission peak resonant frequency appears highly sensitive to the nature and properties of the liquid. This shows that similar structures provide a novel platform for liquid sensors.