Acoustic cloaking device echoes advances in optical cloaking

Aug 15, 2011

Optical cloaking devices that enable light to gracefully slip around a solid object were once strictly in the realm of science fiction. Today they have emerged as an exciting area of study, at least on microscopic scales.

A new twist on this intriguing technology can now be "seen" in the field of acoustics. A team of researchers from the Universitat Politecnica de Valencia and the Universidad de Valencia have created a prototype of an acoustic cloak by using a 2-D .

Unlike sound-canceling technologies that eliminate noise by creating the exact-but-opposite waveform, an acoustic cloak would enable to travel around an object without changing their shape or direction.

The proposed sound cloak, as described in the AIP's journal Applied Physics Letters, would consist of 120 cylinders, each 15 millimeters in diameter.

By carefully arranging them around an object 22.5 centimeters across, the researchers experimentally demonstrated that sound waves of a specific frequency (3061 Hertz, with about a 100-Hertz bandwidth) maintain their original wave-front pattern as they pass around and beyond the object.

According to the researchers, the narrow operating band of the cloak can be overcome by increasing the number of cylinders used to create the cloak.

If such a technique could be applied in real-world designs, it could enable better soundscapes in urban environments, better acoustics in performance halls, and quieter helmets that protect the ears from extreme noises, the researchers speculate.

"Acoustic cloak for airborne sound by inverse design" is published in .

Explore further: Watching the structure of glass under pressure

Provided by American Institute of Physics

5 /5 (1 vote)
add to favorites email to friend print save as pdf

Related Stories

New invisibility cloak hides objects from human view

Jul 27, 2011

For the first time, scientists have devised an invisibility cloak material that hides objects from detection using light that is visible to humans. The new device is a leap forward in cloaking materials, according to a report ...

Next generation cloaking device demonstrated

Jan 15, 2009

A device that can bestow invisibility to an object by "cloaking" it from visual light is closer to reality. After being the first to demonstrate the feasibility of such a device by constructing a prototype ...

Recommended for you

Watching the structure of glass under pressure

17 hours ago

Glass has many applications that call for different properties, such as resistance to thermal shock or to chemically harsh environments. Glassmakers commonly use additives such as boron oxide to tweak these ...

Inter-dependent networks stress test

20 hours ago

Energy production systems are good examples of complex systems. Their infrastructure equipment requires ancillary sub-systems structured like a network—including water for cooling, transport to supply fuel, and ICT systems ...

Explainer: How does our sun shine?

22 hours ago

What makes our sun shine has been a mystery for most of human history. Given our sun is a star and stars are suns, explaining the source of the sun's energy would help us understand why stars shine. ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

hush1
not rated yet Aug 18, 2011
Kewl
Undisturbed sleeping under a bridge with just the right number of blankets,...I mean,... cloaks of cylinders.

Actually, great news for 'new' acoustic anechoic chambers.
Orchestra's members cloaked, without hearing each other.
No more practice "sound proof" rooms.