14 DAY TRIAL // In a research that could hold significant influences for the emerging field of aerial robotics, scientists have recently discovered how flies are able to change their direction so quickly in mid-flight. According to the new scientific paper, it would appear that the insects do so with a shrug of their shoulders, in a manner similar to how a boatman uses oars to change the direction in which his boat is traveling. Wired reports that the study could lead one day to the development of better flying robots.
The secret to the flies' ability to perform aerial stunts is in the joints on their wings, which researchers determined to act like wind-up toys. The study was conducted on the common fruit fly that beat its wings about once every four milliseconds. This rate is a lot higher than the one at which its neurons are firing, so scientists hypothesized that parts of the process had to be controlled automatically. They published their work online, in the April 5 issue of the scientific journal Physical Review Letters.
Using an array of high-definition cameras, mounted around a transparent box containing ten flies, the research group was able to find out that it took no more than 18 wing beats for the insects to make a 120-degree turn. “How much of the wing motion is being controlled by the insect, and how much is going along for the ride, being controlled by aerodynamics?” Cornell University expert Itai Cohen, a coauthor of the paper, asks. “Essentially these insects are swimming through the air, using drag forces to row themselves in whichever direction they want,” in very much the same way a boatman pushes differently in his oars to change course, Cohen says.
“Really the idea is, how do we start to build more efficient and smaller robots that take advantage of aerodynamics to do the things they do, rather than brute force the way we usually do these things We’re in the dark ages as far as building anything like that. We’re nowhere in the ballpark. The insects don’t have to do any thinking whatsoever. They have a natural system that provides just the right amount of torque to the wing,” he concludes.