Bid to create 'invisibility cloak'

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NEW YORK: A new material that could be used to create a real-life Harry Potter-style "invisibility cloak" has been designed by British scientists.

The material, called "Metaflex" may in future provide a way of manufacturing fabrics that manipulate light.

Metamaterials have already been developed that bend and channel light to render objects invisible at longer wavelengths.

Visible light poses a greater challenge because its short wavelength means the metamaterial atoms have to be very small.

So far, such small light-bending atoms have only been produced on flat, hard surfaces unsuitable for use in clothing.

But scientists at the University of St Andrews in Scotland believe they have overcome this problem. They have produced flexible metamaterial "membranes" using a new technique that frees the meta-atoms from the hard surface they are constructed on.

Metaflex can operate at wavelengths of around 620 nanometres, within the visible light region.

Stacking the membranes together could produce a flexible "smart fabric" that may provide the basis of an invisibility cloak, the scientists believe. Other applications could include "superlenses" that are far more efficient than conventional lenses.

Describing their work in the New Journal of Physics, the researchers write: "Arguably, one of the most exciting applications of Metaflex is to fabricate three-dimensional flexible MMs (metamaterials) in the optical range, which can be achieved by stacking several Metaflex membranes on top of one another...

"These results confirm that it is possible to realise MMs on flexible substrates and operating in the visible regime, which we believe are ideal building blocks for future generations of three-dimensional flexible MMs at optical wavelengths."