Just like Mother Nature

Sea urchins that could be a new kind of solar cell
Sometimes the answer lies with a very simple observation. In this case scientists in Switzerland have looked for solar cell designs by peering into the oceans. Sea urchins have a a very high surface area because they are rough. If you look closely the roughness is a very regular structure that is repeating. Using sea urchins as a design these scientists made similar structures from polystyrene and used them to mold nanowires. The array of wires are able to efficiently absorb sunlight more efficiently.
http://www.empa.ch/