Circuits Made of Ink

Xerox claims today that it has mastered a key technique that will make it possible to print transistors at low cost on flexible plastic, using a new semiconducting ink. The advance could speed progress toward devices such as “roll-up” laptop screens or rewritable, fold-up displays for electronic newspapers.

There’s been plenty of work over the last few years on ways to manufacture computer electronics on organic substrates like plastic rather than delicate, rigid, and expensive silicon. (For example, see “Print your Next Computer,” November 2000; “Electronic Paper Turns the Page,” March 2001; and “Flexible Transistors on a Roll,” January 2002.) But most methods involve depositing the transistor material in a vacuum, a process that has proved difficult to control.

By contrast, the new Xerox ink can be inkjet-printed on plastic in the open air, at room temperature. The ink contains nanoparticles that self-assemble at ambient temperatures into stable patterns, according to Xerox researcher Beng Ong, who unveiled the work today at the spring conference of the Materials Research Society in San Francisco.