RP294 Metamaterial

 RP294 Metamaterial

It's not only fantasy authors who are interested in invisibility. Real scientists are fascinated by the idea, too. And lately, instead of being dismissed as impossible, some researchers are saying, “Invisibility cloaks? Hmmm, maybe...”

The key is metamaterial. Metamaterials are man-made structures that bend light in very different ways than natural structures or materials do. When a beam of light hits a natural material—water, for example—The angle of the light changes somewhat, but the overall direction remains the same. When light hits some metamaterials, however, it actually changes direction and points backward. This bounce-back effect can trick our eyes into thinking we don't see anything. Because of the way they affect light, metamaterials are also called backward wave media, left-handed media, and other names.

Researchers at the University of California, San Diego, first showed that they could manipulate light this way in 2000. They created a new kind of material that had properties never seen in nature. One of them was this ability to reverse light. Since then, researchers have been working on repeating those results with different, more flexible materials and for different types of light. In July, 2010, Elena Semouchkina of the University of Michigan presented an invisibility device made of a type of modified glass. Semouchkina's device bends light around an object, hiding it.

In November of 2010 there was another breakthrough. Researchers at Saint Andrews University made a flexible metamaterial that can bend some light wavelengths, including the wavelength we see as the color red. Though their samples are only millimeters long, their creators are confident that they can make bigger ones.

The words “hiding,” “disguise” and “out of sight” may soon have a whole new meaning.