The Printable Transistor

A half century ago, researchers at Bell Labs in Murray Hill, NJ, changed the world with their introduction of the transistor. Since then, the devices have evolved, becoming smaller, faster, and ubiquitous-finding their way into everything from computers to toasters. But today’s silicon transistors are still too expensive or inflexible for some applications. Howard Katz and his colleagues at Lucent Technologies’ Bell Labs hope to solve these problems using not silicon but organic chemistry.

Organic semiconductors, Katz says, would be cheap, easy to manufacture, and printable on flexible plastics that could easily cover large, irregular areas. “If you can’t take advantage of one of those attributes, then you may as well use a silicon chip,” Katz says. The materials already have been used to create electronic paperlike prototypes-cheap, bendable display surfaces that could one day replace paper. Organic transistors might also be used in toys, sensors, or in the best-case scenario, radio frequency identification tags-a sort of price tag of the future-that could instantly relay inventory and purchase information to a store’s computers. But commercial use of organic semiconductors is still several years off, Katz says. “Every part of this needs more research-making it reliable, being able to make a process that you can do over and over again with available equipment, doing it on materials that are flexible.” In his lab, Katz took Technology Review senior associate editor, Erika Jonietz, through the process of testing one of dozens of compounds he and his team are developing.