Microflyer creates quite a flap

The entomopter is a crawling and flying robot, the brainchild of Robert Michelson, a principal research engineer in GTRI's Aerospace, Transportation and Advanced Systems Laboratory. What's particularly unusual about the device is its method of flight; instead of using a propeller or rotor, the entomopter flies by flapping its wings.

The entomopter’s wings are modeled after those of the hawk moth. However, unlike any living creature, the aircraft's twin six-inch wings are paired in an X configuration at each end of the body. "We use what's called a blown wing, where we can vent gas out through the wing to modify its lift," Michelson said.

Resonance—a capacity for storing energy—is built into both an insect and the entomopter, but in different ways. An insect stores energy in its exoskeleton as it flaps its wings. In Michelson's entomopter, the body acts as a resonant torsion spring.

The rapid wing-flapping action is generated through an innovative technology called a reciprocating chemical muscle, which employs a chemical energy source. Through direct conversion, the muscle can also produce small amounts of electricity for onboard systems. In addition, it can provide differential lift enhancement on the wings to achieve yaw, pitch and roll motions for steered flight.

The entomopter attracted notice from the Defense Advanced Research Projects Agency and NASA. The former is interested in the flyer for military reconnaissance.

The entomopter's unique, ultra-high, lift-flight characteristics make it an attractive choice for negotiating the thin atmosphere of Mars. As Michelson sees it, a fleet of entomopters would operate in conjunction with a surface rover—taking off, landing and refueling there in a manner evocative of an aircraft carrier. “Entomopters would serve as the rover's long-distance eyes, scouting points of interest and directing the rover to those locations, or performing their own science experiments," Michelson said.