For relativity long microwaves, Chan says the material could be created in as little as two years. The cloak of illusion won't be covering aircraft or anything else soon however. "Imagine if you confused an F-22 for a Boeing 747 on the radar screen," says Fang. "Instead of making things completely transparent, the parts can be disguised under radars." "This is very intriguing because the theory points out a completely new approach of camouflage," says Nicholas Fang, a researcher in Illinois who recently developed an acoustic metamaterial. The surface on both inner and outer surfaces would be smooth, says Chan, made of an alloy copper or aluminium and a dielectric. Other layers would face outward, reflecting incoming light in very specific patterns to make the object inside look like something else. Some layers would face inwards, and cancel the light coming from the object through a process called destructive interference. The metamaterial the Hong Kong scientists propose, which exists solely as a mathematical model with no physical example yet, would have several layers.
The tiny hills, valleys, and shapes imprinted onto a metamaterial, many times smaller than the wavelengths of light they intend to manipulate, can bend light waves around objects (invisibility cloaks), back towards their source (a universal mirror), or reflect a false image (cloak of illusion). Unlike most materials, which derive their properties from their chemical makeup, a metamaterial gets its special properties from its physical composition. "For example, it can make an apple look like an orange," says Chan. "The metamaterial can turn the appearance of one object into that of another," says Professor Che Ting Chan, a scientist at the Hong Kong University of Science and Technology and coauthor of a paper that recently appeared in the journal Physical Review Letters. Warships may deflect laser strikes, Science Online, Ī cloak of illusion, or a material that disguises one object as another, is being developed by scientists in Hong Kong.Bending light the key to 'invisibilty', Science Online,.Metamaterial brings sound into focus, Science Online,.
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