Alex Davis, a Doctoral Student at Duke University, recently conducted a study of super-black butterflies that could lead to new innovations in super-black coatings, according to cNET, amedia outlet. The most famous of these coatings is Vantablack, which is used for everything from telescopes to art projects.
But ultra-black butterflies like Rajah Brooke’s bird-wing butterflies have created stiff competition for artificial coatings like Vantablack. “Only 0.06 percent of the light reflects back to the eye,” Duke University said in a press release Tuesday. “What makes this phenomenon so fascinating is the lightness and thinness of the butterfly’s natural color. Davis and his colleagues used electron microscopes to take a close-up view of how insects achieved the feat.
Zoom in on the wings of a butterfly to see the layers of the scales. As for the super-black appearance, Duke Describes it as “an optical illusion created by the 3D structure of the butterfly’s wingscales.” The microscope images highlight the details of these nanostructures, which appear in a series of ridges with honeycomb-like structures in the middle. The researchers found that these ridges and columns in the super-black scales were “deeper and thicker” than the “normal” black scales.”
Butterflies are not as black as Vantablack or similar coatings, but the paper notes that they are thinner and can be made at lower temperatures. The study calls for further research into the feasibility of converting this biological miracle into synthetic materials.
In the study, butterflies were carefully examined for using black as a key part of their wing color scheme, and bright blocks of color from blue to green to red pop-ups in ultra-dark backgrounds.
“We think it could be a butterfly sending some kind of signal to a partner or predator,” Mr Davies said. But there are many other possibilities, and we hope to eliminate that. “