sleek shark skin

                         Sleek shark skin

Sharks, the stealthy predators of the deep, may have a thing or two to teach the U.S. Navy. Shark skin contains sleek scales that resemble tiny teeth and are made of a tough material called dentin. The scales create tiny vortices in the water that reduce drag, studies have shown. Shark skin also prevents barnacles and other organisms from glomming on, something called bio-fouling (those sticky creatures cost the Navy at least $50 million each year, one Navy scientist estimated.) The scales are constantly in flux, limiting the surface area to which marine hitchhikers can attach.

Researchers in Germany have developed a synthetic shark skin made of elastic silicone that reduces bio-fouling by 67 percent in tests. The U.S. Navy has funded work to develop similar critter-repellent coatings.