Sci-fi notions of invisibility may not be merely B-movie imaginings for much longer. University of California, Berkeley scientists have developed material that has the potential to bend light around objects — including people — to make them invisible. Initial applications envisioned are military — making tanks, buildings, and even individual infantrymen disappear from view, for example. In tests, researchers from UC-Berkeley and the Lawrence Berkeley National Laboratory were able to construct a prism that bent light “the wrong way” and thus allowing an object appear to vanish. The results were published last week in the online versions of the journals Nature and Science. Similar techniques using microwaves, which are much easier to control, were demonstrated two years ago, but this is the first time that they have been successfully carried out in three dimensions with visible light. “This straightforward and elegant demonstration enhances our ability to mould and harness light at will,” the researchers said in a statement. “Invisibility cloaks [have gotten] a step closer to realization.” The prism used to bend the light was made from metamaterials, substances artificially created using nano-engineering. The material bent the light waves in the opposite direction they are normally refracted through a glass prism. This “negative refraction,” thought to be impossible with naturally occurring materials, was enabled by the fishnet-like silver nanowires used to create metamaterials. Researchers believe the technique can now be developed to create an invisibility cloak that would direct light waves around an object, essentially hiding it because no reflected light would give away its position. Go to: Times Online

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