Having proved the principles of micropower generation, Haile and Ronney now say that the hurdles they face are purely technical. Can this technology be made cheaply and is it mass-producible? One of the major problems they will have to address is their plumbing. At the moment, fuel and air must be pumped in mechanically, but tiny mechanical parts are hard to manufacture and they break easily. Eventually, Ronney would like to make the whole system with no mechanical parts at all, and in theory it is possible to have a non-mechanical pump. The trick is to have the right kind of material, and the quixotic substances known as aerogels happen to have just the required properties — microscopic pores through which the air and fuel can be sucked. “The moral of the story,” Ronney says, “is that with the right materials, you can do anything.”
Whereas the 19th century was the age of machines and the 20th century the age of computers, much of the technological development of the present century is going to be driven by innovations in materials science. Nothing could suggest this more vividly than the potential marriage of hydrocarbons and silicon brokered by the high-tech alchemy of solid-oxide fuel cells and aerogels. Here, elements from across the periodic table will work in concert to realize technologies unimaginable even a decade ago.
Jet's Sons: Former Hollywood SFX man Ewald Schuster gets real small
There are model-plane fanciers, and there are model-plane fanatics, people for whom miniature aircraft are not merely a hobby but, to crib from Richard Meltzer’s eloquent description of record collecting, “the designated essentials” without which “the universe would topple.” Ewald Schuster is definitively in this latter category. “When I was 9 years old,” Schuster says, “I saw a Harrier at an air show, and I realized that I had to have one myself.” For those of you who, like me, tend to think of black hawks and hornets as members of the animal kingdom, the Harrier is an airplane in a class of its own — it is the only jet plane that can hover. Designed by the British company Hawker Siddeley, the Harrier is the result of an insanely complex feat of engineering that overcomes a mass of instabilities to enable a fixed-wing craft to hover in the air like a dragonfly.
For the past decade, Schuster, who is a research technician in the engineering department at USC, has been building his own Harrier from the ground up, every part individually designed and fabricated by hand. At one-sixth scale, it has a 92-inch fuselage and a 60-inch wingspan. So far Schuster has flown it as a conventional jet, but the real challenge is to make it hover, something he hopes to achieve this coming year.
Schuster’s skill with eccentric machinery was honed by his years as a special-effects model maker for Hollywood — he designed the mechanisms for the irascible little fighters in Toy Soldiers and the mechanical tentacles for the aliens in Galaxy Quest. But frankly, he says, working in Hollywood was a bit unsatisfying: “They want everything too fast, and you never get to make things properly.” A few years ago, after an innocent inquiry to the USC Department of Aeronautical Engineering about the specifics of hovering aircraft, he found himself being offered a job. “I like it here,” Schuster says, “because they let you do things properly and I can do my own research.”
In addition to the Harrier, Schuster has fabricated the world’s smallest jet engines. The Harrier itself has a relatively large engine, 4 1/2 inches in diameter and 8 inches long. But Schuster has already made one half that size — 2 1/4 inches by 5 inches — which currently rates as the tiniest documented jet, and he is now working on one half as small again. In his workshop, he lets me hold it in my hand — it’s just 1 1/4 inches in diameter and 2 1/2 inches long. Although it hasn’t been flown yet, Schuster has tested it in the laboratory. At full throttle, the tiny turbine spins at 500,000 revs per minute, a rate that even the bearings’ manufacturers find hard to believe.
Apart from their novelty value, Schuster notes that miniature jets could be extremely useful for surveillance, when you need “something that can fly in very fast, take pictures, then fly out very fast.” The U.S. military has actually been looking for such devices, and Schuster hopes his jets might fit their bill. Moreover, microjets would be a perfect power source for certain applications because jets are intrinsically more fuel-efficient than internal-combustion engines.
True love is never a cheap affair: Schuster reckons that to date he has spent $50,000 on the Harrier alone, plus around 20,000 hours of his time. Each of the smaller jets has cost thousands more. Though USC has provided him with a workshop, the jets are his personal hobby project, and he bears the cost himself. Fortunately, the students find it fascinating, and he now has several merit scholars assisting him with the development of his hovering controls. Surrounded by his beloved planes, Schuster says he has no regrets about leaving the glitter of Hollywood, though he confesses that he would like to work on just one more film — something that would involve a miniature Harrier. “It would be cool to see it in a movie,” he says.
—M.W.
