When does a jellyfish act like a bird?
Leif Ristroph and Stephen Childress, professors at the Courant Institute of Mathematical Sciences, have come up with an answer by creating a four-inch machine that opens and closes four wings, thereby resembling a swimming jellyfish.
Their work, published in the U.K. Royal Society journal Interface, sought to improve on earlier ornithopters, or flapping-wing aircraft.
These previous designs have mimicked the way insects fly. However, such efforts have failed to produce aircraft that are stable—they tend to flip over because they are unable to adjust their bodies the way insects do when in flight.
Ristroph and Childress hypothesized that modeling an aircraft after a jellyfish—i.e., one that relies exclusively on flapping wings—might enhance stability. Their prototype with four distinct wings and a motor was able to remain upright while flying.
“Our current ornithopter allows for the adjustment of wing motions, a capability that is critical for maneuvering flight,” the authors write. “Our scheme of flapping broad wings in and out seems to provide the strong damping of body motions needed for stability.”
The research was supported by a grant from the National Science Foundation.