Created using a 3D printer, the Duke cloak leverages repeated patterns of plastics and air to create a metamaterial with the unnatural property of making sound appear to disappear.
As sound waves approach the multi-tiered, pyramid shaped plastic cloak, carefully patterned holes reroute sound in such a manner that the cloak provides acoustic invisibility while also blending with the surrounding environment, rendering it completely undetectable.
“The structure that we built might look really simple,” said Steven Cummer, Professor of Electrical and Computer Engineering at Duke. “But I promise you that it’s a lot more difficult and interesting than it looks. We put a lot of energy into calculating how sound waves would interact with it. We didn’t come up with this overnight.”
In the future, acoustic cloaks could be used to upgrade the stealth capabilities of a vehicle or improve the acoustics of a symphony hall. However they’re used, though, I will always be impressed by 3D acoustic cloaks because they can hide something in it that actually exists, which to me is pretty awesome.
Image and Video Courtesy of Duke University