Dragonfly Inspiration for Aircraft Design

Stacey Combes, a biomechanist at Harvard University, and her team are using high-speed cameras to study how dragonflies pull off complicated aerial feats that include hunting and mating in mid-air. They can fly straight up, straight down, hover like helicopters, and disappear in a blur. Engineers are looking to the dragonfly for inspiration in small-scale aircraft design. The Harvard team's research was funded by the National Science Foundation.

Transcript

00:00:11 MILES O'BRIEN: This dragonfly is grabbing its meal on the go. STACEY COMBES: This attempt is so fast that unless we film it in high-speed we can't see whether it caught the prey. But when it gets back to its perch, if we see it chewing we know that it was successful. MILES O'BRIEN: With support from the National Science Foundation, Harvard University biomechanist Stacey Combes, wants to understand how dragonflies pull off these complicated aerial feats; hunting, and even reproducing in midair. She and her team set up their lab near a pond outside Boston, right in the heart of dragonfly country. STUDENT: All right, I got one. Oh, I lost it. MILES O'BRIEN: Clearly it's not easy to catch a dragonfly.

00:00:49 STUDENT: I got one. MILES O'BRIEN: Check out this frog. In this specially-built netted enclosure, Combes'team set up eight high-speed cameras. Then they release a dragonfly and some tasty fruit fly prey to watch what happens next. STACEY COMBES: They'll go up in midair, catch the prey with their hands, or with their feet, turn upside down and glide back to the stick. And the whole capture will take maybe a second, or a second and a half. This one's missing about half of its left front wing, and yet it still does an amazing job catching this fruit fly in midair. STUDENT: It only takes about half a second for this to happen. STACEY COMBES: They caught, you know, about ninety

00:01:28 or ninety-five percent of the prey that we gave them. And interestingly, they're one of the most ancient groups of insects. They've had a long time to evolve their skills as predators. MILES O'BRIEN: About three-hundred-million years. These four-winged insects predate dinosaurs. They can fly straight up, straight down, hover like helicopters, and disappear in a blur. And their eyesight? AMBER DesLAURIERS: Almost its whole head is eye. They can see pretty much all the way around their head, except right behind them. MILES O'BRIEN: Dragonflies mate and lay eggs in flight. STACEY COMBES: Do you see her like just dipping in the water? STUDENT: She's trying to lay eggs; the male's trying to mate with her.

00:02:03 MILES O'BRIEN: Combes says engineers are looking to the dragonfly for inspiration in small scale aircraft design. STACEY COMBES: There's a lot of interest in building you know, robotic, small robotic devices. MILES O'BRIEN: And she says better understanding of dragonflies could lead to more effective mosquito control strategies. STACEY COMBES: They may consume thirty mosquitoes a day. They could even consume hundreds a day. MILES O'BRIEN: And that's an idea that could really take flight. For Science Nation, I'm Miles O'Brien.