Plastic Fantastic

“Plastics.” That was the unsolicited career advice young Dustin Hoffman received in the 1967 movie The Graduate. Plastic technology is still on the march and set to revolutionize an important corner of the semiconductor industry.

A couple of recent plastic semiconductor breakthroughs promise to pave the way to improved displays and other innovations. Last November, IBM Corp. announced the creation of a transistor-laden semiconductor sheet that’s easy to manufacture and flexible enough to be rolled up. Lucent Technologies has developed a similar technology that could eventually lead to the creation of electronic books with flexible pages and credit cards with changeable advertising messages.

IBM’s invention uses a tongue-twisting chemical compound, phenethylammonium tin oxide, which gets sprayed onto flexible plastic film. IBM views its technology as a big improvement over conventional semiconductors made out of materials that must be processed at very high temperatures on hard, difficult-to-melt surfaces, such as silicon. The result of the spray-on technology is a semiconductor sheet that performs like a liquid crystal display, but is lighter, more durable and cheaper. Lucent’s technology, while similar to IBM’s creation, uses a different manufacturing process and another type of organic compound called pentacene. It also produces sheets of plastic, flexible transistors.

Either technology can be used to create a variety of different products. E Ink Corp., for example, is working with Lucent to develop “electronic paper” that could finally make portable e-books and newspapers a practical reality. The technology relies on millions of tiny microcapsules filled with a dark dye and light pigment. When charged by the electric field created by the plastic transistors, the microcapsules change colours and create images.

“We’re looking to create books, newspapers and other documents that are instantly available and never go out-of-date,” says Russ Wilcox, vice-president and general manager of Cambridge, Mass.-based E Ink. “We like to say it will be the last book you will ever buy.”

Other potential, plastic semiconductor applications include lighter laptop and PDA displays and credit cards with advertising messages that change in response to a wireless radio signal.

The first products using plastic semiconductor technology are due to arrive in 2002