Pirouz Kavehpour is a mechanical engineer at the University of California in Los Angeles. He and his colleagues studied feathers from gentoo penguins, an Antarctic species, under a scanning electron microscope. The jagged surface of the feathers was full of nano-sized pores. This subtle roughness forces water droplets to slide off rather than stay and freeze. The penguins also release preen oil from a gland near the base of the tail. A bird will use its beak to spread the oil over its feathers. That oil works as a water-repellent.
The Magellanic penguin lives in South America, in warmer climates than the gentoo. It has no pores on its feathers, the researchers found. And it secretes a less-repellant oil. Kavehpour reported his team’s new findings November 22 at the American Physical Society Division of Fluid Dynamics meeting in Boston, Mass.
Ice build-up on penguin wings may not be a big deal for most people. But icing on the wings of an airplane can bring down a craft. So Kavehpour hopes to exploit the birds’ deicing ways to design airplane wings that won’t ice up.