Advances made in thin computing units

IBM Corp says it has found a promising way to deposit thin materials on plastic as researchers move to create flexible, low-power computer screens and foldable semiconductors.

The advance, reported in tomorrow's edition of the journal Nature, has the potential to allow the production of flexible watches, ``smart'' cards, electronic newspapers and wearable computers by using organic chemistry, the largest computer maker said.

The process discovered by researchers at IBM's Watson Research Lab in Yorktown Heights, New York, advances efforts to create ``spray on'' computer gear. The goal is a commercially viable film of transistors that can act like a semiconductor to store digital data or create light-emitting crystals for screens.

"Their experiments have produced a notable advance in making thin films of organic materials," Robert Hamers, a chemist at the University of Wisconsin-Madison, wrote in a commentary accompanying the Nature report.

With added understanding of the electronic properties of the organic materials, "the dreams of cheap, flexible [and perhaps even biodegradable] microelectronics based on organic molecules may soon become a reality," Hamers wrote.

Prototypes are about three years away and products five years out, said IBM spokesman Matt McMahon.

The IBM advance involves the use of pentacene, an organic molecule of carbon and hydrogen atoms that's under wide study as a thin film medium for semiconductors and displays. IBM researchers were able to watch the growth of pentacene crystals and learn that surface preparation was one key to letting the pentacene form large enough crystals for workable transistors.

Until now, pentacene often reacted with a base layer of silicon in ways that created smaller crystals and disrupted the pentacene's electronic properties, McMahon said. IBM found that a layer of another organic substance, cyclohexene, sandwiched between the silicon and pentacene, created large crystals that can be manufactured on a wide scale.

IBM will now try to perfect the process of spraying these very thin layers of molecules onto flexible plastic surfaces. The researchers already have built working flexible transistors, IBM said.