Coating copies microscopic biologica...( Someday your car might have the meta...)

Someday, your car might have the metallic finish of some insects or the deep black of a butterfly's wing, and the reflectors might be patterned on the nanostructure of a fly's eyes, according to Penn State researchers who have developed a method to rapidly and inexpensively copy biological surface structures.

"Only a small fraction of mutations in evolutionary processes are successful," says Akhlesh Lakhtakia, the Charles Godfrey Binder (Endowed) Professor of Engineering Science and Mechanics. "But, evolution has gone on for at least a billion years. A huge range of biological surface architectures have been created and are available."

Lakhtakia and his colleagues, Carlo G. Pantano, distinguished professor of materials science and engineering, and director of Penn State's Materials Research Institute, and Ral J. Martn-Palma, visiting professor, Penn State, and professor department of applied physics, Universidad Autnomia de Madrid, used the conformal evaporated film by rotation (CEFR) technique, to produce coatings that capture the micro and nano structure of biological surfaces in a thin coating of glass. The results appear in recent issues of Applied Physics Letters and Nanotechnology.

In the CEFR technique, the researchers thermally evaporate the material that forms the coating in a vacuum chamber. The object receiving the coating is fixed to a holder and rotated about once every two seconds. The researchers have coated butterfly wings and a fly, creating replicas of these templates with identical surface characteristics. The researchers are using chalcogenide glasses composed of varying combinations of germanium, antimony and selenium.

"With the right temperature, which is room temperature, and the right pressure and rotation speed, the coating process takes about 10 minutes and deposits a 500- nanometer layer," says Lakhtakia.

Some biostructures, such as moth's eyes, which are duplicated t
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