Phononic crystal locally-resonant cavity for sensing metallic oxides nano-powders

Abstract

In this paper, the goal is to specify the type of metallic oxides including Fe2O3, Fe3O4, ZnO, Al2O3, MgO, TiO2, and NiO, provided as nano-powders. The phononic directional coupler is firstly employed and investigated to detect the materials. Subsequently, a novel locally-resonant structure based on the solid-solid phononic crystal is proposed to be used as a mass sensor. This structure consists of the PMMA background with tungsten inclusions and three resonant cavities for increasing the quality factor. There are two hollow cylinders inside the middle cavity filled with the materials whose type should be determined. Filling these cylinders with different target materials results in different resonant frequencies. To specify these frequencies, the transmission spectrum of the structure is obtained via the 3-dimensional finite element simulation method.