Simulated shark skin boosts swimming

Abstract

It's only when you get up close to a shark that you realise how rough the sleek-looking skin really is: it is peppered with millions of microscopic overlapping tooth-like scales. These so-called ‘denticles’ disrupt the smooth flow of water over the animal's surface, reducing the drag that holds them back. Engineers and scientists have been mesmerised by the advantage that the razor-sharp surface gives sharks, but it is impossible to get to the nub of how denticles give sharks a boost without testing how alterations to the skin affect the fish. ‘You can't modify real shark skin’, explains George Lauder from Harvard University, USA. So Lauder and his colleagues Li Wen and James Weaver decided to try to create artificial shark skin instead (p. 1656).