How do flies fly?
Not like birds and airplanes, says Dickinson.
Birds and airplanes stay airborne on wings whose shape and angle create lower pressure above the wing, which helps lift them.
Their flight is explained by a theory called "steady state aerodynamics."
But flies' wings are constantly flapping -- nearly 200 times a second -- and the wings move mostly side to side, not up and down.
To understand the aerodynamic forces generated by flies, Dickinson built a huge model of the wings of a fruit fly, Drosophila melanogaster.
Dubbed "Robofly," the contraption mimics the atmospheric effects of a fruit fly's one-millimeter-long wings flapping in air.
They built a 25-centimeter (15 inch) robotic wing, which flaps and rotates at one-hundredth a fly's speed in a two-ton tank of mineral oil. Three motors move the robotic wing back and forth in precise motions determined by a computer. Bubbles pumped into the tank show the aerodynamic patterns. Sensors measure the forces on the wings during each phase of the stroke.
---courtesy dickison lab