Nature:
The metamaterials used in solar panels, heat detectors, and
specialized cameras absorb light efficiently, but manufacturing
them is usually difficult, expensive, or both. A team led by
David Smith from Duke University in Durham, North Carolina, has
developed a cheap and simple alternative process to achieve a
similar material. The researchers placed a thin layer of gold
on a piece of glass, covered it in a layer of polymer a few
nanometers thick, and then scattered silver nanocubes on the
surface. When light hits the silver cubes, it excites their
electrons, which create a sympathetic excitement in the
electrons in the gold. The resulting "plasmon resonance" traps
the light in the polymer layer; the thickness of the layer
determines what wavelength of light gets trapped. Smith's
technique still needs to be refined by ensuring the silver
cubes are all the same size and finding a nonorganic substitute
for the polymer for use in high-temperature devices. But the
ease of creating the material will likely make such
metamaterials much more useful in consumer products.
