What do the hawkmoth, the fruit fly, and the bird-wrasse fish all have in common? Over millions of years, each of these animals seems to have figured out how to achieve high-lift in their respective medium…. quickly, and with more stability and less heave, pitch, yaw, torque, drag and cavitation than man-made machines have yet been able to approach. The Office of Naval Research wants to know how they do it.
The Office of Naval Research is studying biomimetic materials like elastic polymers and shape memory alloys (SMAs) to see how they can be used to mimic muscle propulsion, and studies are underway to compartmentalize these motions and develop modules to produce a desired navigational motion and control it.
To do this, researchers are studying - among other things - how the rigid-body boxfish turns on a dime, how the fruit fly recovers from delayed stall, and how the hungry hawkmoth stays on target in mid-air while feeding.
"The unchanging body shape of the wrasse during straight ahead swimming, for instance, is not so unlike the Navy's rigid submersibles with one big exception," says Dr. William Sandberg, ONR's primary investigator on the wrasse at the Naval Research Laboratory. "The wrasse propels itself at very high forward speeds using only its remarkable pectoral fins, which also generate substantial lift and thrust even at low speeds. In rough seas at low forward speed and shallow submergence, big cylinders like submarines don't hold position or maneuver too well, but fish seem to have figured it out. The wrasse fin offers promise as a low-speed UUV thrust generation mechanism."
ONR's high-lift biorobotics research efforts fund a number of scientists around the world who are looking at integrating high-lift hydrodynamics, artificial muscles, and neurobased control for the Navy's next generation unmanned aerial (UAV) and underwater UUV) vehicles, and whatever else might come to mind (SEAL suits? artificial muscles in garments?).
"All these biological species are able to do what we can't do yet, but would like to." says Dr. Promode Bandyopadhyay. "The Navy is very interested."