Taking his cues from nature, a University of Virginia aerospace engineer and his team are studying winged insects for inspiration in designs for flying microrobots, a.k.a. drones. The devices could be used for search-and-rescue operations, military surveillance, or package deliveries.
“What is the secret to these fliers?” asks Haibo Dong, an associate professor of engineering. He began studying minute invertebrates in 2009, collecting dragonflies, damselflies, butterflies, and cicadas from ponds and parking lots. The insects are measured, numbered, and “trained” to fly freely as researchers gradually raise the temperature in the lab and attract them with bright lights and sugar water. High-speed cameras capture their motions, and computers convert the images into 3-D animation, revealing just how wings move as they flutter more than 40 times a second.
Dong has found that each kind of insect has a feature worth emulating. Dragonflies, one of the most ancient of insects, can not only move side to side and backward but also change direction by twisting their wings and bending their bodies at high speeds. Damselflies soar for long distances with little energy. Cicadas carry much heavier payloads than other insects. And butterflies fly erratically to avoid capture by predators. Another striking trait: each flier is impervious to rain, pollen, and dirt.
Dong’s team, which has had grants from the U.S. Air Force, is now studying nature-inspired materials to make a model that draws on all of these qualities. In three to five years, the scientists plan to shrink the robot from one foot to a few inches.
The drone will be called the Dragonflyer.
