Now, an 'illusion cloak' that shows you what's not there!

London, Feb 25 (ANI): There was the invisibility cloak and this time it's an illusion cloak - a device that can change an object's appearance.

The technology could ultimately be used to hide military aircraft.

Wei Xiang Jiang and Tie Jun Cui at Southeast University in Nanjing, China, have created a structure that alters the manner in which way radio waves interact with a copper cylinder so that the appearance of the object changes completely.

They guide the waves in a direction that makes the hidden object appear to have different electrical properties.

However, the illusion was visible only when viewed from the side and the imaginary object it generated was the same size as the original. And the illusion device is three times as wide as the cylinder it disguised.

"In principle, this technology could be used to make an illusion of an arbitrary shape and size," New Scientist quoted Cui as saying.

Illusion devices such as these could eventually be used for stealth technology: for example, to "convert the radar image of an aircraft into a flying bird", Cui says.

"Their device is still fairly bulky relative to the original object, so further work needs to be done before a real device can be deployed," says John Pendry of Imperial College London.

However, he added, "It is easier to falsify something than to hide it."

The team next plans to explore ways to design devices with more complex shapes.

The study appears in Physical Review E. (ANI)