Feb. 26, 2008 -- Researchers at the U.S. Navy's China Lake Naval Warfare Center are developing a new material that would shield ships against high-energy weapons like lasers.
The work could help protect equipment and personnel while advancing research in the unique world of metamaterials.
"If you have a ship being hit by a laser, and it was made of this metamaterial, you could reflect the laser beam," said Simin Feng, one of the study co-authors and a researcher at China Lake.
Unlike normal materials, which derive their properties largely from the chemicals that comprise them, metamaterials are artificially made materials that get their properties from their physical structures.
The material Feng and her co-author Klaus Halterman, also of China Lake, have theorized would be made of three layers of conventional materials, with the metamaterials sandwiched between the three layers. Since the material would be thin it should be easily applied and "wouldn't weigh things down," said Halterman.
There are several kinds of metamaterials. Some, like the "invisibility cloak" developed by Duke University Researchers in 2006, channel certain wavelengths of light around a hidden object. Others, like the Navy's, have what is called a negative refractive index.
Stick a straw into a glass of water. The parts above and below the water point in slightly different directions. That's a positive refractive index, and is the case for nearly all materials.
A negative refractive index would occur if you tried to stick the straw into the water and it bounced back at the exact but opposite angle it entered the water.
Now imagine the straw is instead a powerful laser. A ship made of conventional materials struck by such a laser would be sliced in half.
Not only would this ship reflect the beam, the more powerful the beam, the stronger the reflection would be, notes Halterman.
Like all optical metamaterials, their unique properties work only if the size of the structure is smaller than the wavelength of light being used. Since the Navy metamaterial would use very small structures it should repel nearly all lasers.
Recently Feng and Halterman were awarded a grant from the Office of Naval Research to turn their theory into reality. They received the grant after publishing their research in the Feb. 15, 2008 edition of the Physical Review Letters.
Even with the money it will likely be a while before the laser-reflecting material is functional. But if someone were to build it, "it would be very interesting," said Anthony Starr, president of SensorMetrix, a company that does metamaterial research. "A lot of possibilities would be raised. The trick would be making it."
Related Links:
Tracy Staedter's blog: What the Tech?
Duke University's Invisibility Cloak
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