Black color of butterfly wings is not just black, but a complex structure to absorb light, which can be compared with Vantablack, a material made of nanotubes with a record-low reflection rate of the incident light. This is the conclusion reached by researchers from Duke University (USA), who managed to measure the parameters of scales on the wings of these insects. They are designed much more complex array of nanotubes, but inexplicably thinner it several times.

If the official rate of absorption of the incident light at Vantablack is of 99.96%, the scales on butterfly wings it is just two hundredths of a percent lower – of 99.94 %. Visually both looks like an absolute black hole in space. But if Vantablack was created by the people, the butterfly wings is a result of evolution. However, scientists still have no idea why they need such a radical black.

With a thickness of 3-4 nm (20 % of the thickness of the synthetic material, Vantablack), scales of the wings were very complicated. There are ridges, protrusions, cells similar to the cell sites, a kind of sponge, etc. found that the darkest areas have the pieces or ribbed surface, or with thick legs at the base of the SOT. The same areas that these elements of terrain do not have to reflect the 16 times more light. Therefore, they are dark brown, not black.

Overall, an unprecedented level of light absorption in this bioconstruction is achieved due to the roughness of the surface and a huge area of absorption. That’s just how the nanostructures within the scales can withstand this load, being significantly thinner and more fragile than carbon nanotubes? Besides, given the number of butterflies in the world with black color wings, there is a chance that the reproduction of this structure will be easier and cheaper than creating new variations Vantablack. And then the world opens wide opportunities for its application.
Source — Nature Communications