Steering sound beams with origami-inspired phononic structures

Researchers have become increasingly interested in creating and steering sound beams effectively, an essential process to remote acoustic sensing for many related technology applications. Hathock et al. have developed a system to steer sound beams that overcomes the complexities usually associated with the cost and power of acoustic sensing, while offering space saving advantages.

It is extremely difficult to design a phononic structure with the necessary geometry and material properties to achieve angular wave steering and control in air. The researchers created an easily realizable physical system by combining an origami phononic structure with metamaterial inclusions.

“In this work, we utilize the combination of metamaterials, artificial materials engineered to have unusual properties, and reconfigurable origami to make a highly adaptable yet simple structure,” said author Megan Hathock.

Building on past research in origami structures, the researchers combined locally resonant elements organized in periodic lattices, where the dispersion curves are numerically calculated. This mechanism enables switching from one lattice to another and then to a third high symmetry 2D lattice, while controlling one degree of freedom.

The researchers explored the material properties required to achieve Dirac cones in air. By using the origami inspired phononic structure with metamaterial inclusions, they were able to identify useful regions of material properties, which greatly aided the design.

While this study was theoretical, the researchers next plan to experimentally demonstrate an origami inspired phononic structure with metamaterial inclusions. In addition to wave steering for acoustic sensing, these findings could be helpful for those using Dirac cone physics for cloaking, topological wave guiding and nonreciprocal wave guiding applications.

Source: “Origami inspired phononic structure with metamaterial inclusions for tunable angular wave steering,” by Megan Hathcock, Bogdan-Ioan Popa, and K. W. Wang, Journal of Applied Physics (2021). The article can be accessed at https://doi.org/10.1063/5.0041503 .

This paper is part of the Acoustic Metamaterials 2021 Collection, learn more here .