Cloaking device

Yet another Star Trek device makes the move to semi-reality.

The work provides a mathematical “recipe” for bending light waves in such a way as to achieve a desired cloaking effect.

John Pendry, along with colleagues David Smith and David Schurig at Duke University in North Carolina, US, have been testing suitable metamaterials for the device they plan to build.

This, Sir John explained, would consist of a sphere or cylinder wrapped in a sheath of metamaterial which could cloak it from radio waves.

“It’s not tremendously fancy, but that for us would be quite an achievement,” he told the BBC News website.

Professor Ulf Leonhardt, author of another cloaking paper in Science, described the effect for light as a “mirage”.

“What you’re trying to do is guide light around an object, but the art is to bend it such that it leaves the object in precisely the same way that it initially hits it. You have the illusion that there is nothing there,” he told the BBC’s Science in Action programme.

The work could have uses in military stealth technology – but engineers have not yet created the materials that could be used to cloak an aircraft or a tank, John Pendry explains. Professor Pendry’s research has been supported by the US Defense Advanced Research Projects Agency (Darpa).