Butterfly Wing Nanostructures Achieve Ultrablack Coloration

A team at Duke University is studying butterflies with wings that are 10 to 100 times darker than everyday black objects. As little as 0.06% of the light that hits the ultrablack butterfly wings is reflected back to the eye. This percentage is close to the blackest black coatings made by humans to help solar panels absorb more energy or enable line telescopes to reduce stray light. The butterflies achieve this light-trapping effect using wing scales that are only a few μm deep — just a fraction as thick as the blackest synthetic coatings. The black patches on the wings of some butterflies are 10 to 100 times darker than everyday black objects. Clockwise from top left: Catonephele numilia, Parides iphidamas, Heliconius...