Plastic semiconductors promise disposable chips.
Silicon microprocessors provide the brainpower for today’s computers and other electronic devices. But fabricating these chips is an expensive and time-consuming process. Now a far cheaper, easier-to-manufacture integrated circuit-one made of plastic rather than silicon-is on the horizon. If these plastic-based chips prove practical, they could help give rise to inexpensive, flexible, even disposable electronic devices.
One startup looking to make that vision a reality is Plastic Logic, which sprang out of the University of Cambridge last November with physicist Richard Friend at the scientific helm. It’s not the first time Friend has put polymers to work in electronic devices: in 1992 he helped launch Cambridge Display Technology to commercialize light-emitting diodes made from organic polymers for use in flat-screen displays (see “Displaying a Winning Glow,” TR January/February 1999). Then, in 2000, Friend and his colleagues demonstrated that they could print polymer integrated circuits-the technology at the heart of Plastic Logic.
Armed with a staff of 10 and venture capital backing of more than $2.4 million from firms such as Midland, MI-based Dow Venture Capital Group and Amadeus Capital Partners of Cambridge, England, Plastic Logic intends to bring polymer transistors to market for use in products where silicon microchips are simply too expensive. Polymer-based circuitry is not nearly fast enough to run a PC, but it could be just right for use in “smart” electronic tags for tracking merchandise or in the electronics used in large flat-panel displays. And because polymer chips can be flexible, they could open the door for handheld computer gadgets that could be folded or rolled up like paper. With these and other compelling markets beckoning, says Friend, “We know why we’re developing the technology. It’s not a case of a technology in search of a use.”
Plastic Logic is not the only company to see the potential of plastic electronics. What sets the Cambridge startup apart from others in the field is its manufacturing approach. Friend’s team dissolves specially designed semiconducting polymers to form an “ink” and then prints the circuitry onto a flexible substrate, employing the same technology used by an ink-jet printer. It’s “a very effective and elegant way of delivering polymers to the sites,” says physicist Ananth Dodabalapur of Lucent Technologies’ Bell Labs. “The big advantage of plastic transistors,” he adds, “is that you can produce them cheaply.”
Plastic Logic has yet to specify just how much cheaper than silicon they think their circuitry will be. According to CEO Stuart Evans, “Cost is difficult to pin down at this early stage.” Still, he says, “It is conceivable that we could make a simple [radio-frequency identification] tag for a penny.” According to Nick Darby, director of technology at Dow Venture Capital Group, Plastic Logic aims to have a working prototype of its new chip ready by the summer, and a product ready for market in three to five years.
Plastic Logic still has some hurdles to clear, though. For one thing, its manufacturing process still involves an expensive initial step borrowed from conventional chip making to prepattern the substrate so the polymer ink doesn’t run. “It’s not a business-model killer, but it’s certainly an area that could be improved,” says Kimberly Allen, director of technology and strategic research at San Jose, CA-based research firm Stanford Resources.
Meanwhile, some of the company’s competitors, including Lucent, are currently working out the details of an alternative manufacturing technique that involves creating the semiconductor pattern with stamps. Eventually, says Dodabalapur, the two techniques could be used together-the stamping process might replace Plastic Logic’s initial lithography step, for example.
Ultimately, says Dodabalapur, “My feeling is that the two techniques will figure among the winners.” If so, Plastic Logic could soon help to create what Evans calls “a parallel universe” of cheap, smart, disposable electronic devices.