Nov 22 2013
WE HAD JOGGED a hundred feet, and already the man beside me was straining. But his face showed triumph— triumph over the impossible. Sixteen years ago in Fremont, Nebraska, a seed truck crushed Roger Charter’s legs. Both were amputated above the knee. For more than a decade the onetime star athlete fought for a normal life with traditional wooden legs. But the hopelessness of it ate away at his spirit.
Now, thanks to that resilient spirit and new limbs made possible by the miracles of advanced materials, Roger Charter (opposite) is the first such amputee ever to run. “My old wooden legs weighed 15 pounds apiece and hurt my stumps—I’d clomp two blocks and have to sit and rest,” said Mr. Charter, today a dispatcher for the Union Pacific Railroad in Omaha. “My new legs weigh half as much and flex like real.”
Those high-tech legs comprise a tidy little inventory of advanced materials: knees and ankles of light titanium alloys born of the space age, shins of a powerful composite of carbon fibers pressed into a matrix of resin, sockets of a flexible but strong new polyethylene to fit comfortably on the residual limbs.
And the feet? “The most difficult part,” acknowledged John Sabolich, president of a prosthetics firm in Oklahoma City and a pioneering designer in advanced materials. “The human arch is like a complex leaf spring, almost impossible to duplicate. Fortunately a new plastic provided the springiness.”Like Roger Charter, all of us will find our future shaped in part by profound changes taking place in the stuff things are made of.
Plastics, so versatile that the same substance that makes your garbage bags also armors U. S. Army tanks, have surpassed metals in volume sold. For tomorrow manufacturers are talking about synthetic fibers—cousins of the plastics—bringing us sweaters that change color with the turn of a dial and suits that change their cut at fashion’s whim.
Composites, pound for pound the strongest of all materials, have moved beyond pricey tennis rackets and golf clubs into the sinews of aircraft and missiles and now enter mass production. Ceramics, everyone’s dream material but a nightmare to work with, soon will bring cleaner-running auto engines in the fight against air pollution and global warming.
What about steel and other alloys, shouldered aside by the flashy synthetics? They are countering with new blends to recapture old markets. Even staid concrete is blossoming. There’s a materials scientist out there who is casting cement coil springs, and another who built a concrete hang glider.
The people concocting these materials will tell you they are working a revolution for cash loans for bad credit.
“For the first time in history,” observed Merton Flemings of the Massachusetts Institute of Technology, “we can design materials precisely to fit our needs, molecule by molecule, atom by atom.”
They get help from incredibly sophisticated tools. New microscopes reveal atoms nestled in their lattices almost as clearly as we see eggs in a carton. Lasers lay down atoms on surfaces so artfully as to endow them with entirely new properties: Insulators become conductors, metals become glasses. Magnetic cannons firing ion beams harden metals and ceramics against corrosives. Fulfilling an age-old dream, computer graphics enable materials scientists to study a complex molecule on a screen, rotate its shining galaxy of atoms, and select where to place an additional atom for a desired effect.
Yesterday materials makers were mainly metallurgists. Today they must also be chemists, ceramists, engineers, and physicists. In their labs you often see them staring at the wall; follow their gaze and you see a copy of the periodic table, that cryptic tabulation of the elements they so cleverly manipulate.
Little to their liking, these scientists find themselves caught up in global competition. Japan, the Soviet Union, the major European countries, China—all are locked in the crucial struggle to develop new materials and processes. At present the United States leads in research but often lags in commercialization. And the stakes are high.
“Materials are the building blocks of the future,” observed Rudy Pariser, former research director for the Du Pont Company. “Today’s advanced material is tomorrow’s commodity.”
“Tomorrow” can be a long time. On average, a decade elapses between test tube and marketplace for a new material, with exhaustive testing in between. Many deplore this slowness. But haste can be costly. I heard some of the horror stories: How Britain’s Rolls-Royce Ltd., switching from metal jet-engine blades to light composites, went bust because the blades had not received a rigorous “goose test” to determine the effect of bird impacts — and they shattered.
How U. S. Liberty ships, welded together by the hundreds during World War II, often sank with tragic loss of life because defective steel lost its toughness in the icy North Atlantic, permitting small cracks to explode into catastrophic rents.
THE USUAL CAUTION flew out the window, though, with the recent uproar over superconductors. Even in the arcane world of physics, superconductivity stands as a marvel: a state of matter in which electricity flows forever without resistance. No current is lost, no heat generated in superconductivity.
It does not come easily. Superconductors lose electrical resistance only when subjected to intense cold. Traditionally this has required immersion in liquid helium at 4 Kelvin (-452°F). This makes superconductivity cumbersome and vastly expensive, sharply limiting its uses. (We encounter it most frequently in the costly medical process known as magnetic resonance imaging.)
Since its discovery in 1911, scientists have searched for materials that would “go superconductive” at higher temperatures. They made little progress until 1986, when physicists Georg Bednorz and Alex Milner in Zurich cooled a black ceramic pellet and saw it lose resistance at 30K. Many compare the significance of their Nobel Prize-winning achievement to the development three decades earlier of the famed transistor.
Scientists rushed to their laboratories, spurred by the new discovery. Their goal was a material that would super conduct at a temperature above 77K—still cold, but the point at which nitrogen liquefies. Nitrogen is easier to handle than liquid helium and could reduce costs to one-tenth.
The Bednorz-Muller ceramic contained the rare earth lanthanum—not your everyday conductor —along with barium, copper, and oxygen. Experiments that followed successfully replaced lanthanum with yttrium, then bismuth, and then thallium, and steadily increased the critical temperature. The historic leap—to 90K —came with an yttrium compound.
It triggered a scientific Mount St. Helens. Around the world TV cameras focused on coin-size magnets magically floating above superconducting ceramic disks amid mists of liquid nitrogen. Scientists regaled the press with visions of miniaturized superconducting motors, massive underground magnets storing electricity to power entire cities, transmission lines carrying current without loss of an electron, and, most exciting of all, magnetically levitated trains whispering across the land at 300 miles an hour.
How far off are such dramatic applications? Impressive progress is being made, but the obstacles are daunting. The crumbly ceramics of high-temperature superconductors lack the flexibility of metallic wires. They balk at carrying heavy current loads: Exceed the critical current point, and they cease to superconduct. Solutions lag because scientists do not yet understand the basic physics involved—how high-temperature superconductors work.
The fact that they do work, however, has stimulated prodigious efforts to harness them.
One of the most intriguing artifacts to date is a small superconducting generator made in England. Its fist-size coil carries ceramic wire fabricated by Imperial Chemical Industries (ICI) in Runcorn. Though years from commercialization, it generates small amounts of power—and encouragement.
Simpler superconducting devices are also being developed, mainly for use in passive electronics systems such as communications receivers and amplifiers.”We were already in the ceramics business when the new superconductors came on the scene,” said Richard Cass of HiTc Superconco in New Hope, Pennsylvania. “Radar receivers with our superconducting components give a signal at least 50 times stronger than copper; half a dozen of them are already being tested by the Army.”
IN WHAT GUISE will high-temperature superconductors first serve us consumers?
“Possibly in your TV antenna,” said Mr. Cass. “A component the size of a golf ball gives vastly better reception than conventional metal. Companies are developing liquid-nitrogen coolers the size of a cigarette pack. The two could fit inside your TV. Allow three years for the superconducting element.”
The advantages that superconductors offer in electronics are not lost on the U. S. military. The Army, Navy, Air Force, and Strategic Defense Initiative Office have strong programs for applications research. DARPA, the Defense Advanced Research Projects Agency, funds 37 separate projects at a total cost of 30 million dollars a year. The appeal is strongest in space defense, where launch costs of $10,000 a pound inspire miniaturization.
“We’re going to need tremendous computational power in space,” said Harold Weinstock, who coordinates the Air Force program. “A Cray 2 computer is not large—no bigger than a few file cabinets. But there’s the monstrous cooling system, with its huge power requirements. Superconductors could slash its size and reduce the power need drastically.”
Computer circuitry itself offers an obvious market for superconductors. Here the current would be carried by thin films, just as films of gold and other conductors form the nerve systems of today’s chips. Film experiments held high priority when I visited IBM’s Thomas J. Watson Research Center in New York.
“We’re working with all three of the ceramic superconductors,” said IBM’s Robert Laibowitz in his lab. “They can carry millions of amps per square centimeter—enough to operate many electronic devices. “But it’s hard to reproduce the films reliably. Further, the heat required to make superconducting films is too much for the silicon chips they attach to. It could take years to work things out, but we’re making progress.”
So important is this technology to national competitiveness that a presidential advisory committee has urged special collaboration between business, universities, and government. IBM has joined forces with two other research leviathans, AT&T Bell Laboratories and MIT. A similar consortium links Du Pont, Hewlett-Packard, and Los Alamos National Laboratory in New Mexico.
The effort to tame high-temperature superconductors ferments worldwide. I saw intensive programs in Britain, France, and West Germany. All three are dwarfed by Japan’s.
Japanese scientists have filed more patent applications for superconductors than the rest of the world combined. More than 600 have flowed from Sumitomo Electric, Japan’s leading manufacturer of electric wires and cables. While U. S. consortia are still organizing, a Japanese consortium headed by the renowned physicist Shoji Tanaka counts more than 90 scientists in elaborate new facilities.
What about the ultimate goal, a material that superconducts at room temperature? No need then for awkward liquid nitrogen. Many believe that if such a substance exists, its discovery awaits understanding of how high-temperature superconductivity works.
ODDLY it was ceramics, today’s headline material, that gave birth to materials science some 13,000 years ago. Villagers in Japan discovered that if you cooked a clay vessel, it hardened into an entirely new substance—ceramic pottery—and retained its hardness ever after. Unknowingly these early ceramists caused atoms in the clay to lock tightly together, in what chemists call covalent and ionic bonding.
Today ceramics are riding a resurgence of interest that some call the New Stone Age. Partisans point out that compared with steel, ceramics can be harder, lighter, stiffer, and more resistant to heat and corrosion. They can. But go back again to that ancient pottery: Drop it and it shatters. Today’s ceramics behave somewhat the same.
“The problem is brittleness,” explained Victor Zackay, a materials specialist with Teledyne Corporation. “Companies have spent billions of dollars to develop useful ceramic devices, and in most cases they have failed because of brittleness. Metals, because of their crystalline structure, can deform under stress instead of fracturing, and still do their job. Stress ceramics, and their atomic bonding prevents the crystalline planes from sliding over each other—deforming. Instead a crack opens, and the object fails catastrophically.
“Before ceramics are accepted as reliable, they must be made so they can fail gracefully. This will not be easy. But ceramics offer far too many advantages to discourage trying.”
The driving dream is the ceramic engine. “Ceramic engine parts offer enormous advantages over metals,” said Richard Alliegro of the Norton Company, a Massachusetts research and development firm that already markets ceramic ball bearings. “Engines would run more efficiently if they could run hotter. But metal would melt; instead we install costly radiators to get rid of that valuable heat. With ceramics we can harness the heat—and get rid of the bulky radiator.”
M OST EXPERTS AGREE that the greatest advances are being made in Japan. Here, where pottery began, government and industry have poured money into ceramics development.
The Japanese also have kindled intense grass-roots interest, known as ceramic fever. The fever traces in part to the relentless drive of the Kyocera Corporation, the leading maker of ceramic packages for computer chips.
“We saw a need to stimulate public acceptance of ceramics to help drive industry,” said Ryusho Nagai, Kyocera’s director of international affairs. “We began producing consumer items — ceramic scissors, ballpoint pens, sushi knives. Meanwhile MITI, the Ministry of International Trade and Industry, built the Fine Ceramics Center. The fever spread.”With Kyocera chairman Kazuo Inamori, I admired ceramic products gracing the lobby of his Kyoto headquarters: scissors made of zirconium oxide, so hard as to rarely need sharpening; ceramic prostheses—skullcaps, elbows, hip joints, knees. We paused at turbocharger rotors being built for an experimental Isuzu diesel. They were made of silicon nitride, increasingly the ceramic of choice.
“We minimize brittleness by quality control,” said Mr. Inamori. “By a precise mix of our ceramic powders, in clean rooms kept free of contamination.”
Mr. Nagai and I toured a Kyocera plant just outside the sacred imperial city. Ball mills pulverized powders of aluminum oxide and silicon nitride to the fineness of particles in cigarette smoke. Products cooked inside squat furnaces, aglow like Shinto shrines. Technicians processed sheets of sapphire— aluminum oxide ceramic —that would become tooth implants and microchip wafers. I stroked a slab bigger than my notebook.
To see ceramic auto parts in action, photographer Chuck O’Rear and I followed the beacon of snow-sheathed Mount Fuji to Yokahama, to Isuzu’s Ceramic Research Institute.
Institute director Hideo Kawamura gestured, and technicians raised the hood of a low sedan emblazoned with the name Ceramic (page 769). Nothing fancy, I thought on seeing the metallic-looking diesel engine. But wait! The radiator was missing, the engine tiny. This car was using its heat, not rejecting it.
“We’ve put 5,000 kilometers on it at high speed, up to 150 kilometers an hour,” said Mr. Kawamura. “Our tests indicate a ceramic engine will last five times as long as metal.”
I spun the Ceramic around Isuzu’s test track, and it handled nicely. But it gave trouble starting. “Ceramic engineering is very difficult,” acknowledged Mr. Kawamura.
Another Japanese partnership has staked a bold claim on the ceramic frontier. Each month NGK, the huge manufacturing company, casts 8,000 turbocharger rotors that give pep and power to new Nissan Cedrics and Fair Ladys — appealing inducements to buyers in the land of ceramic fever. But there is a downside: The rotors require costly individual spin testing for flaws, and the bulk price of ceramic powders hovers about $150 a pound.
The U. S. government effort, like Japan’s, has focused on the ceramic auto engine. To me it seemed quite skimpily funded; R & D for ceramic car parts received only 11.3 million dollars for fiscal 1989. A similar program develops ceramics for diesel truck engines.
Both are run by the Department of Energy.
The auto engine that emerges from the DOE program will be different from the one in your car. Instead of being powered by pistons, it will use a ceramic gas turbine strikingly similar to a jet aircraft’s propulsion system.
“Ceramic car engines will run at 2500°F,” said Saunders Kramer, manager of the DOE program. “So far the rotors and other ceramic parts test well to 2200° and then fail rapidly. We need better ceramic powders to remove flaws and eliminate additives used in sintering—the baking process.”
How long before ceramic engines hit U. S. highways? “We have millions of test miles to go before we prove them,” said Arvid Pasto of GTE, the electronics giant. “We’ve reduced parts failures to one in a million. The goal is one in a billion. I see commercialization in the late 1990s.” Asserts Saunders Kramer of DOE: “We’ll have automotive gas turbines on the road by the year 2000—at worst.”
Some experts wonder if the Japanese will maintain their costly commitment. “They’ve invested 20 years and billions of yen,” observed Sylvia Johnson, a ceramist at SRI International. “Some day they must decide how long they want to continue losing money. I’ve found them to be divided.”
Two advanced ceramics, both developed by Corning Incorporated, already play roles in our daily lives. One is the catalytic converter in your car’s exhaust system— a triumph of ceramic fabrication. The other is Corning Ware, a basic feature in 70 percent of U.S. kitchens.
Ceramics find increasing use as thin coatings on objects made of conventional materials. When next you visit your hardware store, look at the drill bits—the ones with the high price tags. These are coated with titanium nitride, a ceramic that extends the cutting life fivefold over steel. Many experts see in coatings a way to escape ceramics’ vexing problems of brittleness and shaping.
The expertise of U. S. ceramics makers is growing. The Carborundum Company, a U. S. subsidiary of British Petroleum, is building a plant in West Germany to manufacture silicon carbide seal rings for European autos. GTE turns out tens of thousands of small ceramic cutting tools daily. At Norton, Jack Lucek conducted me through the process that converts silicon nitride powder into gleaming black ball bearings.
Could these intriguing spheres defy the ceramics’ age-old curse of brittleness? “Try and break them,” suggested Mr. Lucek. I took two the size of marbles to a blacksmith shop in Maryland. Smithies Peter Austin and Dana Dameron locked tongs around one, then bludgeoned it mercilessly with a sledgehammer. Not a nick marred the ball bearing. But the steel plate beneath wore deep dimples from the blows. The tingling wonder we felt—was it a touch of ceramic fever?
FOR A NEW MATERIAL to succeed, it usually must be able to muscle aside a metal or glass; after all, they got there first. The masters of this have been the synthetic plastics, a family of materials that didn’t exist a century ago.
In 1907 Belgian immigrant Leo Baekeland invented Bakelite, a hard synthetic substance for making billiard balls and wire insulation. But Baekeland did not completely understand the complex chemistry he exploited.
That triumph fell to Du Pont chemist Wallace H. Carothers. In the 1930s he combined carbon, hydrogen, nitrogen, and oxygen—the basic ingredients of you and me — into long molecular chains. Neoprene and nylon were the results—the first wholly synthetic materials ever made by a knowing manipulation of molecular structure. They launched the materials revolution that now reshapes our world.
“Our building units,” explained Du Pont’s Dr. Pariser, “are simple carbon-based molecules known as monomers, derived from oil, natural gas, and coal. With the help of catalysts we connect monomers into long molecular chains known as polymers. The shape of a chain helps determine a polymer’s properties.
“With Kevlar, an aramid fiber, the molecules lie straight, giving strength and stiffness. In synthetic rubber they’re a tangle; stretch them straight and they try to curl up again like rubber bands, giving springiness.”Competition is keen in every area of materials development. But nowhere is it as fierce as in the group of polymers called plastics.
Today 60,000 different plastics vie for a place in the market. Each week six or so new ones arrive at Underwriters Laboratories outside Chicago, where rigid testing for flammability and other properties qualifies plastics for components of UL-listed products.
Key targets, naturally, are Detroit’s auto assembly lines, which feed so heavily on metals and glass. At GE’s Application Development Center in suburban Southfield, a display of plastic car parts—fenders, bumpers, control panels—peered like safari trophies from a lobby wall.
“One of our best known successes is plastic headlamps,” said Adgild Hop, the center’s director. “Most Ford models use our integrated Lexan units.” He referred to GE’s renowned see-through plastic that also gives bulletproof protection to the Pontiff in his Popemobile. More recent breakthroughs for the auto industry are thermoplastic bumpers and fenders.
But the plastics people admit to problems. Plastics can cost a dollar or two a pound, while metals cost pennies. And in the cutthroat auto business a difference of pennies makes decisions. Further, plastic parts don’t always work as one-for-one replacements for metal.
EACH YEAR U. S. companies make 30 million tons of plastics—half the tonnage of the nation’s wheat crop. Thirty percent goes into packaging—the myriad bags, bottles, and boxes that find niches in every environment from freezer to microwave. Far too many of these find a final niche in landfills or on the roadside.
Are the manufacturers responding? They are, along with a score of concerned state legislatures. The major debate is not whether to act, but how: Should plastics be required to be degradable, like paper? Or should they be recyclable, like steel and aluminum?
Your average plastic container will linger on the roadside perhaps two centuries before those tight polymer molecules break down. How to hasten this? Research takes three approaches: biodegradability, in which a natural additive such as cornstarch gives bacteria a toehold; chemical degradation, in which additives cause the plastic to crumble away; and photodegradability, in which the sun’s ultraviolet light attacks the molecules.
But degradability can weaken plastics. And environmentalists question the effects of decay residues. Degradability also could conflict with recycling, now gaining momentum.
To foster recycling, which now recaptures less than one percent of all plastics, nine states have laws requiring a deposit on plastic bottles. States are also weighing mandatory collection of plastics, now law in Rhode Island.
Recycling gets a boost with a joint venture by Du Pont and Waste Management, Inc. Next spring Du Pont will open the first two of five planned recycling plants, with trucks delivering an initial 30 million pounds a year.