Brazilian Beetles Hold Key to Faster Computers

By Brandon Keim 05.23.08 | 12:00 AM

For decades, scientists have dreamed of computer chips that manipulate light rather than electricity. Unlike electrons, photons can cross paths without interfering with each other, so optical chips could compute in three dimensions rather than two, crunching data in seconds that now takes weeks to process.

For now, though, optical computing remains a dream. The chips require crystals that channel photons as nimbly as silicon channels electrons -- and though engineers have been able to imagine the ideal photonic crystal, they've been unable to build it.

Enter a beetle known as Lamprocyphus augustus. In a study published this week in Physical Review E, Purdue University researchers describe how the inch-long Brazilian beetle's iridescent green scales are composed of chitin arranged by evolution in precisely the molecular configuration that has confounded the would-be fabricators of optical computers.

By using the scales as a semiconductor mold, researchers hope to finally build the perfect photonic crystal.

"We haven't been able to manufacture materials at the nanometer resolution. We knew the ideal structure, but we couldn't make it," said study co-author Michael Bartl, a University of Utah material scientist.

Bartl's team stumbled across L. augustus by sheer luck. Study co-author Lauren Richey, now a Brigham Young University undergraduate, studied beetle iridescence for a high school science fair project. She asked BYU doctoral chemistry student Jeremy Galusha, also a co-author of the study, to examine L. augustus with his lab's electron microscope.

When the researchers scoped the scales, they noticed something strange: No matter the angle of viewing, the scales always appeared in the same shade of green.

That's unusual for iridescent surfaces, which derive their color from light refracted through semi-transparent layers. Further study revealed that the quality came from the scales' molecular arrangement, which had the same pattern as the atoms of carbon in a diamond.

http://www.wired.com/science/discoveries/news/2008/05/photonic_beetle