New Invisibility Cloak. Not Only Invisible, But Also Inaudible. As If Nothing Was There

By | December 26, 2011

http://www.alphagalileo.org/AssetViewer.aspx?AssetId=60412&CultureCode=en&MaxWidth=800&MaxHeight=400Researchers from Karlsruhe Institute of Technology (KIT) have now succeeded in demonstrating for the first time an invisibility cloak for elastic waves. Such waves also occur in strings of a guitar or drum membranes.

It is as if Harry Potter had a cloak that also makes him unhearable. "Maybe a place of peace and quiet in the Christmas season," say the KIT researchers, who succeeded in transferring the concepts underlying the optical invisibility cloak to acoustic waves in a plate.

"The key to controlling waves is to specifically influence their local speed as a function of the 'running direction' of the wave," says Dr. Nicolas Stenger from the Institute of Applied Physics (AP). In his experiment, he used a smartly microstructured material composed of two polymers: A soft and a hard plastic in a thin plate. The vibrations of this plate are in the range of acoustic frequencies, that is some 100 Hz, and can be observed directly from above.

The scientists found that the sound waves are guided around a circular area in the millimeter-thin plate in such a way that vibrations can neither enter nor leave this area. "Contrary to other known noise protection measures, the sound waves are neither absorbed nor reflected," says Professor Martin Wegener from the Institute of Applied Physics and coordinator of the DFG Center for Functional Nanostructures (CFN) at KIT.

via New Invisibility Cloak. Not Only Invisible, But Also Inaudible. As If Nothing Was There | Before It’s News.

2 thoughts on “New Invisibility Cloak. Not Only Invisible, But Also Inaudible. As If Nothing Was There

  1. Ann

    Ok, sounds are important, but what about olfaction, less we be in the same uneasy situation as Hermione Granger when she discovered fragrances permeate the Salvio Hexia cloak.

    1. Xeno

      I always figured since the cloak was bestowed by Death himself, that it would include smells, sounds, everything except Snape’s 6th sense…

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