Under the microscope, the texture of the wings is visible.
Credit: Ohio State
The electron microscope revealed that the Blue Morpho's wings aren't smooth, but of a texture that resembles a clapboard roof with rows of overlapping shingles radiating out from the butterfly’s body.
Under the microscope, the rice leaves provided an even more surreal landscape—with rows of micrometer-sized grooves, each covered with nanometer- sized bumps—angled to direct raindrops to the stem and down to the base of the plant. The leaf also had a slippery waxy coating, which keeps the water droplets flowing along.
The electron microscope reveals the texture of the rice leaves.
Credit: Ohio State
After studying the textures of the butterfly wings and rice, as well as shark skin and other textures, the researchers made molds of them in silicone and cast plastic replicas. To emulate the waxy coating on the rice leaves and the slippery coating on shark skin, they covered all the surfaces with a special coating consisting of nanoparticles.
In one test, they lined plastic pipes with the different coated textures and pushed water through them. The resulting water pressure drop in the pipe was an indication of fluid flow.
They dusted the textures with silicon carbide powder and tested how easy the surfaces were to clean. The shark skin came out the cleanest, with 98 percent of the particles washing off during the test. Next came the rice leaf, with 95 percent, and the butterfly wing with about 85 percent washing off. By comparison, only 70 percent washed off of the flat surface.
Bushan believes the rice leaf texture might be especially suited to helping fluid move more efficiently through pipes, such as channels in micro-devices or oil pipelines. He believes the Blue Morpo's wings, with their ability to keep the butterfly clean and dry, might lead to better texture for medical equipment, where it could prevent the growth of bacteria.