Courtesy of Science/AAAS
"Many bright, iridescent beetles and butterflies get their brilliant colors not from pigments, but from the way tiny structures on their bodies reflect light. These structures have long been of interest to scientists, who hope to imitate these photon-controlling crystals to build better solar cells, sensors, and other optical devices--potentially even optical computer chips."
"Previously, researchers had shown that the beetle reflects what appears to us as a shining green color in the form of leftward-circulating polarized light (as the light travels, its corresponding electric field rotates leftward). Shining only right-turning polarized light at the beetle causes it to lose its green color (see the pictures above).
The left-turning reflection occurs because of complex helical nanostructures in the beetle's exoskeleton. Its exoskeleton is made up of hexagonal, pentagonal, and heptagonal cells containing yellow cones surrounded by green."
"Tightly packed, concentric arcs (or spirals) on these cells look very similar to a type of liquid crystal. Because scientists already understand how liquid crystals form, this new association may help them understand how the insect's optical structure self-assembles."
"Researchers speculate that these beetles may even use such photonic complex substructures to communicate with each other via light or to ward off predators."
http://www.technologyreview.com/blog/editors/23881/
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