When made from an appropriate material, a diamond-like structure would create a large photonic bandgap, meaning the crystalline structure prevents the propagation of light of a certain range of wavelengths. Materials with such bandgaps are necessary if researchers are to engineer optical circuits that can manipulate visible light.
On the Path of the Beetle: From BYU to Belgium and Brazil
The new study has its roots in Richeys science fair project on iridescence in biology when she was a student at Utahs Springville High School. Gardners group at BYU was helping her at the same time Galusha was using an electron microscope there and learned of Richeys project.
Richey wanted to examine an iridescent beetle, but lacked a complete specimen. So the researchers ordered Brazils Lamprocyphus augustus from a Belgian insect dealer.
The beetles shiny, sparkling green color is produced by the crystal structure of its scales, not by any pigment, Bartl says. The scales are made of chitin, which forms the external skeleton, or exoskeleton, of most insects and is similar to fingernail material. The scales are affixed to the beetles exoskeleton. Each measures 200 microns (millionths of a meter) long by 100 microns wide. A human hair is about 100 microns thick.
Green light which has a wavelength of about 500 to 550 nanometers, or billionths of a meter cannot penetrate the scales crystal structure, which acts like mirrors to reflect the green light, making the beetle appear iridescent green.
Bartl says the beetle was interesting because it was iridescent regardless of the angle from which it was viewed unlike most iridescent objects and because a preliminary electron microscope examination showed it
|Contact: Lee Siegel|
University of Utah