A synthetic material mimics the complex microscopic structure of brilliant butterfly wings to achieve a bright blue colour.

Butterflies of the genus Morpho are known for their dazzling blue wings (pictured right). The colour arises from densely packed layers of ridges that cover the scales on the wing surface. The ridges are structured such that light waves reflecting off the ridges interfere with each other, creating the blue colour. The tight, semi-random packing of the ridges makes the wings appear bright across a wide range of viewing angles.

To recreate these features in a reflective material, Jung Shin at the Korea Advanced Institute of Science and Technology in Daejeon, South Korea, and his colleagues deposited silica microspheres onto a surface and then sprayed layers of titanium dioxide and silicon dioxide over them. The resulting film (pictured left) had just the right mix of regularity and disorder to create the even blue colouring.


Adv. Mater. http://dx.doi.org/10.1002/adma.201200521 (2012)