(USA)

Sharks should inspire the design of more efficient planes and cars, according to new research.

Tapping into the aerodynamic excellence of sharkskin, honed by 400 million years of evolution, the teams from Harvard and the University of South Carolina say it offers solutions for developing products – like planes, cars and drones that ‘outperform traditional designs’.

“The skin of sharks is covered by thousands and thousands of small scales, or denticles, which vary in shape and size around the body,” explained Professor George Lauder, an evolutionary biologist at Harvard. “We know a lot about the structure of these denticles — which are very similar to human teeth — but the function has been debated.”

In tests, the researchers used the denticle dimensions of the world’s fastest shark, the shortfin mako. They ‘3-D printed the shapes on the surface of a wing with a curved aerodynamic cross-section, known as an airfoil’.

“Airfoils are a primary component of all aerial devices. We wanted to test these structures on airfoils as a way of measuring their effect on lift and drag for applications in the design of various aerial devices such as drones, airplanes, and wind turbines,” said August Domel, a Harvard Ph.D.

In trying out a variety of configurations, the engineers found that as well as reducing drag, the ‘denticle-shaped structures significantly increased lift, acting as high-powered, low-profile vortex generators’. Vortex generators are the small devices used in cars and planes to make them more aerodynamic by altering the air flow.

“You can imagine these vortex generators being used on wind turbines or drones to increase the efficiency of the blades,” added Katia Bertoldi, William and Ami Kuan Danoff Professor of Applied Mechanics at SEAS and co-author of the study. “The results open new avenues for improved, bioinspired aerodynamic designs.”