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Just Two Words: Plastic Chips


It's called the seduction room. Eastman Kodak Co. (EK) uses it to woo visitors with the vivid colors that light up new-breed video screens. They're made from organic light-emitting diodes, or OLEDs. And in the room's side-by-side comparisons with ordinary liquid-crystal displays (LCDS), the difference is impressive: Colors are more vibrant, resolution is crisper, and the OLED screens can be viewed from farther off to the sides without visual loss.

Kodak fell for OLEDs long ago. In 1979, researcher Ching Tang was looking for an inexpensive plastic solar cell to convert light into electricity. Ironically, says Willy C. Shih, president of Kodak's Display & Components Group, Tang stumbled on a polymer recipe that "did just the opposite." His plastic converted electricity into light -- with unprecedented efficiency for an organic compound. Kodak has been smitten ever since.

Today, the whole display industry loves plastics. Every maker of TV sets and computer monitors is working on OLED screens. In Japan, a dozen companies and four universities are collaborating to build a 60-inch OLED display by 2007, says Kimberly Allen, director for technology research at market watcher iSuppli Corp. Don't look for anything larger than a laptop screen much before then. One reason: The little organic light bulbs that make up the picture elements, or pixels, burn out after about 8,000 hours of use. That's fine for cell phones, which only get used intermittently. But desktop monitors in offices would last only a year or so. Shih says Kodak's latest chemicals promise a tenfold boost in performance.

Displays, though, barely scratch the surface of what's coming in plastic electronics. A typical home probably has only a handful of displays, but it has hundreds of food containers, toys, medicine bottles, and other items, each of which could be endowed with a modicum of computer smarts if brittle and costly silicon and glass can be replaced with plastic. With the advent of cheap plastic circuits, food packages could sport a "sell by" imprint that keeps track of time and turns bright red when the limit is reached. Kids could converse with even low-priced toys, not just the premium ones. "And a sensor in my daughter's asthma inhaler could warn when it's close to empty," says Elsa Reichmanis, director of polymer materials research at Lucent Technologies Inc.'s Bell Laboratories. "The possible consumer applications are endless."

Moreover, in a world of polymer electronics, virtually any company could become a chipmaker. Thanks to inks made from conductive and semiconductive polymers, it will soon be possible to print proletarian circuits on almost any surface using an inkjet printer or offset press. A billion-dollar semiconductor factory isn't needed, notes Jim Tully, chief of Gartner Inc.'s research arm in Europe, "so this will open the door for a large number of manufacturers" to make poly chips for a host of everyday products.

THINGS THAT THINK

Polymer Electronics can't challenge silicon in heavy-duty number-crunching jobs now, although that may be just a matter of time. Plastic transistors today are positively poky compared with silicon versions, concedes Alan J. Heeger, the University of California at Santa Barbara physicist who shared a Nobel prize in 2000 for helping to create the first conductive polymer in 1977. But the speed of poly transistors has been rising steadily. "Every improvement," says Heeger, "expands the potential market."

How much might the poly-chip market be worth? Motorola Inc. sees an opportunity for new applications that could reach as much as $300 billion ultimately -- more than double the total worldwide sales of silicon chips last year. Since plastic chips would cost a fraction of silicon-chip prices, hitting that target would take many times the 100 billion silicon chips cranked out last year. So Motorola is working with Dow Chemical and Xerox to develop printing methods that could spew out flexible plastic circuits like so much newspaper, at perhaps 300 feet per minute. The trio's big breakthrough came in April: Beng Ong, manager of poly-chip research at Xerox Research Centre of Canada, unveiled a new ink for printing plastic chips that can be used anywhere. (Previous inks were sensitive to oxygen, so printing had to be done in enclosures filled with an inert gas.)

In addition to catalyzing new markets, plastic chips could also supplant silicon chips in a growing number of current applications. By combining polymers with other organic materials, such as carbon nanotubes, composite materials "will sidestep today's limitations and compete with the very best silicon transistors," predicts John A. Rogers, a materials scientist at the University of Illinois. In March, Rogers' group unveiled a new way to produce high-speed plastic chips. It resembles the rotogravure technique used to print raised-ink letters on business cards.

Organic-inorganic hybrids also show promise. In March, a group of IBM researchers led by David B. Mitzi revealed a technique that can coat plastics with a very thin semiconducting film of metal, such as tin sulfide. Electrons zip through this structure up to 10 times faster than typical poly chips, and Mitzi says an additional fivefold increase may be possible. Last year, University of Toronto researchers showed that hybrid chips can generate pulses of infrared light for fiber-optics systems if the polymer is salted with 5-nanometer dots of lead sulfide.

For Europe, the ascent of polymer electronics holds special promise because of the Continent's strong chemicals industry. So the European Union in March coughed up half the cost of PolyApply, a $29 million, five-year collaboration involving 20 companies and research institutes. The first goal, says PolyApply coordinator Luigi Occhipinti, head of strategic research at STMicroelectronics, will be to develop polymer radio-frequency identification (RFID) tags -- essentially smart bar codes with antennae that enable individual packages and products to communicate with computers in factories, warehouses, stores, and, eventually, homes.

The final result, predicts Occhipinti, will be "ambient intelligence." Cheap chips will be everywhere, even on the surface of textile fibers, wirelessly jabbering back and forth. "Things that think," he adds, will be "truly ubiquitous."

Only plastic chips can be cheap enough to make this happen, notes Bernard J. Kippelen, a University of Arizona researcher. There's a limit on how small, and hence cheap, silicon chips can get -- 5 cents to 10 cents is considered rock bottom. But even that's too expensive for consumer giants such as Procter & Gamble Co., which would need tens of billions of tags a year. "Wal-Mart, P&G, Gillette, and lots of others all want lower-cost tags," says Paul F. Baude, head of RFID development at 3M. If plastic tags bring the price down to a penny, says iSuppli's Allen, digital readouts on subway and commuter cards that show the balance may be possible.

Companies in the silicon-chip game are also exploring polymeric potentials. Researchers at Hewlett-Packard Co.'s (HPQ) HP Labs, for example, foresee building ultratiny transistors from custom-designed organic molecules. One idea is a row of hydrogen atoms encircled by a benzene ring that serves as an on/off switch by sliding back and forth. The notion of molecular electronics, or moletronics, is sizzling at places such as Cornell University, State University of New York at Stony Brook, and Pennsylvania State University. Because of the chemical versatility that polymers offer, it may be possible to tailor polymer chains that serve as memory storehouses or duplicate the logic circuits in microprocessors. That might lead to pinhead-size plastic chips with the power of today's supercomputers -- made in virtual test tubes, not billion-dollar silicon factories.

Moletronics probably won't be a viable contender for silicon's crown until after 2010, says Bell Labs's Reichmanis. By then, you may read the news on thin, flexible screens that unroll like window shades. Some plastic displays -- alternatives to OLEDs -- are already moving into the commercial arena. One closely watched technology is "electronic paper," developed by E Ink in Cambridge, Mass. The first consumer product is an electronic book that Sony and Royal Philips Electronics have just launched in Japan. The size of a thin book, it opens to reveal a paperlike, black-and-white screen that changes the text from page to page by rotating its tiny pixel balls, each of which is half black, half white. Behind the screen is enough memory to store an entire library of 500 digital books. So its name, LIBRI?, is apt. Cost? Just $380.

LIBRI?'s screen is rigid, but Philips' new Polymer Vision (PV) unit is itching to launch a flexible follow-on. By summer, PV will be churning out prototype five-inch displays just three sheets of paper thick, says General Manager Bas van Rens. They can roll up inside a fat fountain-pen-size holder. The case could be fitted with an antenna to download news and e-mail wirelessly from the Internet whenever a user whips out the e-pen. And the length of the case could grow, eventually accommodating tabloid-size screens. For the British market, the tubes might even be topped off with an umbrella. By Otis Port in New York, with Rachel Tiplady in Paris and Faith Arner in Rochester, N.Y.


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