Avery Thompson for Popular Mechanics:  A common sight in the forests and meadows of India is the common rose butterfly. Known for its velvety black wings and colorful body and tail, the common rose spends its day gathering nectar from flowers like zinnias and Egyptian Starcluster. But soon, the common rose might be known for something else—making our solar panels more efficient.

"I was in a conference and somebody was presenting about butterflies and their nanostructures, and I was intrigued," says Radwanul Siddique, lead author of a recent paperpublished in the journal Science Advances. Siddique's paper uses these butterfly nanostructures as inspiration for a new type of solar cell design that can absorb more sunlight than traditional solar panels.

"A lot of insects have structural colors, where their colors come from nanostructures," says Siddique. For instance, the bright blues and greens of many Morpho butterflies are caused by tiny tree-like shapes in the wings, less than a millimeter across. These nanostructures absorb and reflect different colors of light at different angles, so the butterfly appears to 'shimmer' and change colors in the air.

The common rose butterfly has a similar trick. Its velvety black wings get their color from tiny microscopic holes that trap and absorb light, giving the butterfly a blacker color than would be possible otherwise. And to an engineer like Siddique, who works with solar cells, a type of structure that absorbs more light is exactly what he needed.  Full Article: