It might look like a quirky plastic model of an ancient Egyptian pyramid, but this model is in fact a 3D ‘acoustic cloak’, created using just a few perforated sheets of plastic. The device reroutes sound waves to create the impression that both the cloak and anything beneath it are not there. A refined version of the technology could one day be used for sonar avoidance and to refine noise in concert halls.
We haven’t quite figured out how to build an optical invisibility cloak just yet, but researchers at Duke University have now successfully created the world’s first 3D omnidirectional acoustic invisibility cloak. In other words, they’ve invented a device that will not bounce back sound waves that strike it, no matter what direction they come from. This effectively renders the structure (or anything beneath it) completely invisible to sound-based detection methods like sonar. The structure, which looks like a futuristic hybrid of a pyramid and a pagoda, consists of stacked layers of perforated plastic.
