At the Sydney Olympics in 2000, the joke was that triathletes were swimming their best times because of sharks in Sydney Harbour. That would definitely make me swim faster, but it didn’t explain why swimmers in the nearby pools were also breaking records.
Those Olympic Games marked the debut of Speedo's Fastskin swimsuits, a revolutionary technology that was modeled on the hydrodynamics of real sharkskin. The suits covered most of a swimmer's body, because the material had proven to be even more efficient in water than bare skin.
Did you know? Swimmers wearing these Fastskin suits won 83 percent of the medals in the pool at the Olympics in 2000 and accounted for 13 of the 15 world records broken.
Since this time, the sharkskin technology has been adopted by famous swimmers such as Michael Phelps and has become an integral part of swimsuit design.
So how does it work? Well, a shark's skin is not as smooth as it looks. It is formed with thousands of tiny scales called dermal denticles, or "skin teeth," and each scale has ridges on it that follow the flow of the water along the shark's body, from front to back. These ridges are hydrodynamically efficient because they reduce the drag of the water in the same way the dimples on a golf ball allow it to travel long distances in the air. (Read more about how the golf ball works here.)
Did you know? The fastest species of shark have higher ridges on their scales to channel water more efficiently. The fastest shark, the Shortfin Mako, can reach speeds of up to 32 km/hr.
Sharkskin swimsuits are part of a growing trend called biomimicry, in which scientists use nature to inspire new technologies. Another example is Velcro, which was invented when scientists examined burs under a microscope to determine how they stick to clothing so well (they use miniature hooks to catch the microscopic loops in woven clothing).
Sharkskin technology is also being used outside the world's elite swimming pools. Engineers are developing ways to make airplanes and ships more fuel-efficient using the same concept and are already well on their way to greening the planet with technology that sharks have been using since the age of the dinosaurs.
How Speedo Created a Record-Breaking Swimsuit (Scientific American)
Bechert, D.W., Hoppe, G., & Reif, W.-E. (1985). On the drag reduction of the shark skin.Presented at the AIAA Shear Flow Control Conferenc. Boulder,CO. Distributed as AIAA paper.
Article first published August 18, 2011