What do butterflies and bubbles have in common?

What do butterflies and bubbles have in common? Both can project iridescent colors in the same way.  When a team of biologists happened upon a Florida breeder’s buckeye butterflies--which are usually—brown—sporting brilliant blue wings, they jumped on the chance to explore what caused the change in color. The team led by scientists from UC Berkeley and the Marine Biological Laboratory, with funding from the National Science Foundation, found that buckeyes and other Junonia species can create a rainbow of structural colors by merely tuning the thickness of the wing scale’s bottom layer(the lamina), which creates iridescent colors just like soap bubbles.   They compared the structural architecture of blue scales with wild-type brown scales and found that only the thickness of the lamina differed, and this pattern held across a comparative study of nine different species of Junonia. The team says understanding the simple change in thickness of the butterfly’s lamina is helping them recognize how butterfly wing color is created and evolves. Future research into how butterflies produce photonic nanostructures with optical properties could help engineers develop new ways to produce photonic nanostructures for solar panels or iridescent colors for paints, clothing, and cosmetics.