Invisible cloak material more likely to produce enhanced vision -

A material has been developed which could one day provide full invisibility to the naked eye for the first time, providing cause for celebration for super heroes, child wizards and old perverts across the world.

The ‘smart’ material, or ‘metamaterial’ is the closest step yet to providing actual cloaking, as well as being used to contact lenses in order to provide “perfect eyesight”, according to St Andrews University.   Whether x-ray vision is possible is, as yet, undetermined.

The findings, published by EPSRC Career Acceleration Fellow Dr Andrea Di Falco, signal a move from the previous incarnation of cloaking material which was only able to shield light at infrared frequencies.

However the new flexible film, which uses tiny atoms that can interact with light, is more likely to have applications for lenses in the near future due its powers of refraction. 

A big challenge for Di Falco has been to make the metamaterials constituent part – meta-atoms –small enough to be able to interact with visible light at around 620 nanometres.  Previous incarnations of materials with ‘invisibility’ characteristics were able to shield objects from Terahertz and Near Infrared waves, however the new material will be able to manipulate fully visible light waves with shorter wavelengths.

The metamaterial, named Metaflex, does not absorb the light, effectively making it refract and bend round an object, rendering it undetectable to the naked eye.

In order to enable this technique a flexible material constructed from polymer and a silicon support is used which allows the meta-atoms to be freed from the hard surface they are constructed on.  It is predicted that once stacked together they can create an “independent, flexible material, which can be adopted for use in a wide range of applications.

Prof Thomas Krauss, also involved in the story,  believes realistic applications for the technology lie in enhancing vision.

“By stacking together substrates we are able to build a 3D material, which has the potential to act as a cloaking device.  However at this point it is possible to do this on micro-sized objects, so we are not able to produce anything on that scale at the moment though it is possible in priciple,” Krauss told Techeye.  “What it is likely the technology will be used for in the next three to five years is for developing much more powerful lenses, I can see a route this already.”

In a statement Di Falco had the following to say:

“Metamaterials give us the ultimate handle on manipulating the behaviour of light. The impact of our new material Meta-flex is ubiquitous.  It could be possible to use Meta-flex for creating smart fabrics placed on disposable contact lenses to create superlenses that could further enhance vision,” said Di Falco. “Typical lenses generally have some form of limitation, such as aberration or limited resolution, but these perfect lenses would have none of these deficiencies.”