No Flights of Fancy

Animal-inspired innovations for airplanes

- By Abha and Deepa Jain

Airplane wings that flap. Or have saw-toothed edges. Or have surfaces that ripple. These features might seem out of reach for aircraft. Yet, many animals, like owls and dolphins, use such traits to move. (No, dolphins don't fly. But both air and water are fluids, or substances that flow. So, physics-wise, sharks and swifts are similar.)

From the beginning of aviation, animals influenced aircraft design. Even today, critters' amazing traits help them outperform most planes. Check out some animal-inspired innovations you may see on airplanes one day.

Flapping Forward

Most airplane wings are stiff, with hinged flaps that move. These flaps change the amount of upward force, or lift, that the wings experience. Unfortunately, they also increase drag-a backwards-acting force-and make movement clunky.

Bird wings, in contrast, are better and smoother liftcontrollers. Engineers are borrowing from them to make wings that flex in any direction. Nick Cramer helped develop such a wing. He's now an engineer at Supernal, an aviation company in Sunnyvale, California. The wing his team developed has three features similar to the bones, cartilage, and feathers of bird wings. "The last feature is a rod that runs down the wing's center and twists the wing," he says. "This is similar to what birds use when coasting on the wind."

Even cooler are wing-parts built with shape memory alloys. These materials "remember" different shapes at different temperatures. They can change shape without electricity or mechanical hinges. Imagine a wing that flaps on its own!