Whirly like a bird

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, lie quickly concluded that as a water mover it would never amount to anything of practical value. Then he started drinking 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 tip 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 QUICK

Lockheed Martin's F-22 Raptor

INNOVATOR: 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. "Yon 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.

A BAND-AID FOR AIRPLANES

Sandia National Laboratories Composite Doubler Repair Technique

INNOVATOR: DENNIS ROACH

Even though carbon graphite and other "composite" materials have had their lightness, strength, and durability put to good use in tennis rackets, golf clubs, and countless other leisure items, they're too costly and too untried to make entire commercial jetliners out of them. But there's no reason, thought Dennis Roach, not to use them as high-tech Band-Aids to repair the jets when their sheet-metal hulls crack,

A third of the nation's commercial jets am more than 20 years old and may carry anywhere from 10 to 50 patches, which are usually made from aluminum sheets and attached with rivets. Riveting a patch is not only time consuming--it can take a jet out of service for an entire (lay, which can cost airline companies more than $100,000--but can sometimes actually introduce new cracks.