Fly-O-Rama!

Illustration by Stephen Rountree FLUTTER BUG
Drosophila melanogaster
Beating 200 times a second, the fruit fly's wings create some of the most complex aerodynamics found in nature; here we simulate the blur from a 1/1000-second snapshot. Illustration by Stephen Rountree

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In the basement of the Valley Life Sciences Building at the University of California, Berkeley, biologist Michael Dickinson walks down a cinderblock hallway to an anonymous steel door. Beyond it lies a small, windowless room crammed with high-speed video cameras and lasers and computer cables draped as thick as cobwebs. In the center of the room is a glass tank big enough to hold a vending machine. This is Robofly.




The tank looks empty, except for a piece of plastic shaped like an insect wing, which dangles from a mechanical arm. But when Dickinson turns on a filter, the tank sprays a creamy mist of bubbles. The tank, it turns out, is filled with 2 tons of mineral oil. Dickinson taps on a keyboard, and slowly the wing begins to move through the oil. It swings forward and back, transforming the bubbles from a disorganized cloud into slow-motion swirls and falling curtains of diamonds.




Dickinson stands before Robofly, carefully watching vortex after vortex. A real fruit fly-an escapee from some other experiment, no doubt-drifts by, its wings beating 200 times a second and stirring up tiny, invisible vortices of their own. But Dickinson ignores it. Robofly has been his obsession for more than a decade, ever since he built the first prototype in Germany. Back then, he used sugar syrup in the tank. "There was sugar everywhere in the lab," Dickinson recalls, "and the maids went on strike. They refused to clean our lab until my advisor did something about the sticky American."




Stickiness is a good way to sum up Dickinson's approach to science. Once he attaches himself to a problem he doesn't let go until he's solved it. For almost his entire career, he has been stuck on one seemingly simple question: How do flies fly?




Though engineers figured out decades ago how to build airplanes that cross oceans, the aerodynamics of insects continue to baffle them. The way an airplane generates lift can be accounted for by a straightforward concept: The air streaming over the top of the wings exerts less pressure than the air below, and that imbalance keeps the wings aloft. But insects, though equipped with barely a brain to speak of, make complex maneuvers far beyond an airplane's capabilities. They turn quicker than any fighter jet and land upside-down on ceilings. "These animals can move perfectly sideways, they can move backward and forward, they can rotate in place," says Dickinson. "Every time we do an experiment, we wonder how the hell do these little sesame-seed-size nervous systems do this?"