Blue Color of Morpho Rhetenor
May 17, 2014
Photographer: Greg Parker; Greg's Web site
Summary Author: Greg Parker
The metallic blue coloration of the Morpho Rhetenor butterfly is due to the microstructure of its wings. The wing scales have a fine periodic structure that acts like a photonic crystal (diffraction grating) to incoming white light. This structure effectively filters the white light and only strongly reflects the blue component. This is an example of biomimetics, where Nature leads the way in elegantly solving problems in optics and mechanics that we can incorporate into everyday products. Blue coloration due to pigment is relatively uncommon in Nature, possibly because many materials that appear blue are toxic to life. Nature's way around this problem is to create blue coloration not by using pigment, but by only reflecting the blue component of white light. I actually have used the basic structure provided by Morpho Rhetenor as the starting template in a computer-modeled design for an even more efficient blue light reflector -- using more appropriate optical materials. This led to a patent on a new type of photonic crystal device - courtesy of the Natural World. Note the Morpho Rhetenor is native to neo-tropical South America.