Researchers at Stanford University in California have taken a lesson from birds to develop mechanical wings that can change shape and maintain flight even after ramming into a wall. Ben Gruber reports.
STORY: Amanda Stowers is beating up on her drone as her professor David Lentink watches on with glee. It may seem cruel but it's all in the name of science. No matter how hard or how many times Amanda hits the drones' wing, it always recovers and keeps on flapping. Stowers says that even drones equipped with advanced sensors can't avoid the inevitable. At some point they'll fly into something. (SOUNDBITE) (English) AMANDA STOWERS, GRADUATE STUDENT, RESEARCHER, STANFORD UNIVERSITY, SAYING: "As much pre-processing and sensors as you can do, you might still occasionally hit things and this could be quite detrimental. And so if you can be more robust when hitting something you could potentially go into a more risky environment." Environments like the inside of a structurally damaged building after an earthquake as part of a search and rescue operation. Currently drones are designed after helicopters or fixed wing planes, both of which cannot sustain mid-air impact. The team wanted to develop a mechanism that could take a beating and maintain flight. The answer came in the form of a bird's wing which, much like a human arm, has joints to give it flexibility. Lentink says mimicking nature is easier said than done. (SOUNDBITE) (English) DAVID LENTINK, ASSISTANT PROFESSOR OF MECHANICAL ENGINEERING, STANFORD UNIVERSITY, SAYING: "So I think one of the big challenges about studying birds and applying that in technology is making the translation from what you find in nature to something that you can actually build in a lab." But they overcame that challenge. The key, says Stowers, was designing their drone to flap like a bird. A birds' flapping motion creates a centrifugal force that keeps it flying even after it collides with something, recovering in a fraction of a second over the course of a single wing beat. David Lentink says that having wings that change shape has other advantages as well. (SOUNDBITE) (English) DAVID LENTINK, ASSISTANT PROFESSOR OF MECHANICAL ENGINEERING, STANFORD UNIVERSITY, SAYING: "The most important thing about being able to change you shape in flight is that every flight speed, every manoeuvre has a different shape that's optimal." And optimal shape means better efficiency, allowing drones of the future to manoeuvre in cluttered environments using less energy.