Broad omnidirectional acoustic band gaps in a three-dimensional phononic crystal composed of face-centered cubic Helmholtz resonator network

Abstract

Broad omnidirectional band gaps in a three-dimensional phononic crystal consisting of a face-centered cubic array of spherical air voids connected by cylindrical conduits in solid background are numerically and experimentally demonstrated. With a low material filling fraction of 37.7%, the first bandgap covers 3.1–13.6 kHz frequency range with 126.1% gap-over-midgap ratio. Finite-element method is employed in band structure and numerical transmission analyses. Omnidirectional band gaps are observed in only two-period thick slabs in the 100, 110, and 111 orientations. Experimental transmission characteristics are in good agreement with numerical data. The phononic crystal can be employed in low-frequency sound proofing.

Acoustic metamaterials characterization via laser plasma sound sources

“…Due to their remarkable acoustic properties, PCs and AMMs, simply termed thereafter AMMs, already find application in various technological fields with broad commercial potential 11,12 , such as room acoustics and noise insulation [13][14][15] but also in radical acoustic innovations, e.g., the development of acoustic super-lenses, low-frequency reflectors, acoustic cloaks and particle manipulators [16][17][18][19][20][21] . Additionally, AMMs have been used to create acoustic wave decelerators and acoustic traps for quantum sensing and computation [22][23][24][25][26][27] . The field of AMMs is dynamic and expansive with new applications continuously appearing.AMM design and development is based on established mathematical and computational tools.…”