Sharkskin-inspired swimsuits received a lot of media attention during the 2008 Summer Olympics when the spotlight was shining on Michael Phelps.
Seen under an electron microscope, sharkskin is made up of countless overlapping scales called dermal denticles (or "little skin teeth"). The denticles have grooves running down their length in alignment with water flow. These grooves disrupt the formation of eddies, or turbulent swirls of slower water, making the water pass by faster. The rough shape also discourages parasitic growth such as algae and barnacles.
Scientists have been able to replicate dermal denticles in swimsuits (which are now banned in major competition) and the bottom of boats. When cargo ships can squeeze out even a single percent in efficiency, they burn less bunker oil and don't require cleaning chemicals for their hulls. Scientists are applying the technique to create surfaces in hospitals that resist bacteria growth — the bacteria can't catch hold on the rough surface.