Ron Barrett took a bunch of tiny beams and plates an inch or so long and assembled them into a small paddle that looked something like a pocket comb. Since the material he used was piezoelectric, which means its molecules contort when in an electric field, the paddle would bend and twist like a fish tail--as much as 8 degrees, depending on how and where he applied a small voltage. But when Barrett put the paddle in the water and watched it flop along, he quickly concluded that as a water mover it would never amount to anything of practical value. Then he started thinking about helicopters.
Controlling a helicopter means adjusting the pitch of its rotor blades, which requires thousands of gears, pushrods, and other linkage pieces stuffed into the hub at the center of the rotor. If any one of these parts fails, the chopper will often just fall out of the sky. For this reason, the complex gizmo is inspected and maintained constantly and at great cost. Piezoelectric blades, Barrett realized, could provide all the twisting without the complexity. To prove it, Barrett, an aerospace engineer at Auburn University, built two piezoelectric "stabilators"--blades that twist to control a helicopter's movement--and fixed them to opposite blades of a radio-controlled mini-helicopter. They steered the tiny chopper perfectly while cutting the number of parts needed to control the machine from 94 to 5. "It's basically the same way birds control their flight," says Barrett. "It's based on 280 million years of R&D; on nature's part."
Last September, Barrett demonstrated the helicopter to the Defense Department, which is interested in using it for drug enforcement. Barrett is looking to scale his stabilator up for full-size helicopters, and he's experimenting with even smaller versions that might be useful for, say, inspecting bridge girders and military reconnaissance.
FINALISTS
Nimble and QuickLockheed Martin's F-22 RaptorInnovator: James Blackwell
When the Pentagon put out its wish list for the next-generation jet fighter back in 1986, the jaws of every military contractor dropped. The new jet would have to be invisible to radar, like the B-2 Stealth Bomber, and it would have to be more maneuverable than the nimble F-15, the current fighter. Lockheed's James "Micky" Blackwell, now president of Lockheed Martin's aeronautics sector, quickly pulled together a team in the company's secretive Skunk Works to make it happen.
The first thing the team did was take aim at the B-2's external panels. So that they can absorb rather than reflect radar signals, giving the plane its stealth qualities, the B-2's panels are made of exotic composite materials that cost a bundle. "You don't need eye of bat and ear of newt to get stealth," says Blackwell. "You just need to find the right shapes." His team fashioned the Raptor's surface so that it scattered the radar signals in a way that made it difficult to detect, which allowed the use of less costly, more robust materials. They also designed the plane's shape to give it better maneuverability. The Raptor's high thrust-to-weight ratio makes it the only aircraft that can fly straight up for more than a few seconds. To make the Raptor easy to fly, two onboard supercomputers monitor all the plane's sensors and boil down a complex combat situation into a simple diagram and recommendation for action--"Shoot!" for example.
The Raptor was also designed for easy maintenance. Thanks to greater use of electronics and to new materials and manufacturing techniques, the engine has half as many moving parts as the F-15's, and technicians can get their hands on any major system without having to remove any other components. The plane detects most faults on its own and can electronically notify technicians of the need for replacement parts. The Raptor passed its first flight test last September. The Air Force is expected to order 339 Raptors at $80 million apiece. The first full squadron of Raptors will most likely take to the air in 2005.
Flying doughnutSikorsky Aircraft's CypherInnovator: James Cycon
After the U.S. Marine barracks were bombed in Beirut in 1986, the military renewed its long-standing interest in building an unmanned aircraft capable of hovering over streets or forests behind enemy lines and relaying pictures of potential threats back to field headquarters. Helicopter-like designs didn't fit the bill because their exposed blades were almost guaranteed to fail if they so much as grazed a tree branch or the side of a building. One solution was to try to protect the rotor or propeller by covering it with a sort of shroud, creating, in effect, a flying cylinder or disk. But that still left the tail rotor--the smaller, vertically mounted blade at the back of a helicopter--exposed. And without the tail rotor, the main rotor could cause the craft to twist, making it unstable and clumsy to maneuver.
But aerospace engineer James Cycon and his colleagues at Sikorsky Aircraft had a radical thought. Why not replace the tail rotor with a second rotor inside the shroud? This rotor would be identical to the main rotor and would be horizontally mounted over it, except that it would spin in the opposite direction, thus counteracting the tendency of the first blade to twist the aircraft. What's more, varying the angles of the blades of the two rotors by slightly different amounts would create small rotational forces that would allow precise tilting or turning of the aircraft in any direction.
The result was Cypher, a prototype car-size flying doughnut. Cypher has a global positioning satellite receiver and radar tied in to a remote laptop computer. All an operator has to do is indicate on a computer map where he wants the machine to go, and it will plot a route, take off, and navigate itself. It is smart enough to avoid bumping into solid objects and even knows not to look directly at the sun with its sensitive infrared camera.
"Controlling it is like playing a video game," says Cycon. "The aircraft has enough smarts to take care of the details." On the battlefield, Cypher has brawn as well as brains--it hauls cargo like a truck. In October last year Cypher showed in tests that it could go behind enemy lines to deliver payloads, lob grenades, and drop spikes that puncture the tires of enemy vehicles.
