With an Ultrathin Film, a Big Step Forward for Flexible Electronics

posted on 20 Jan 2009 23:19 by technologynews

Flexible electronics — the kind that might be used in “smart” clothing, say, or in foldable displays that could make reading news online more like reading it in print — are still far from an everyday reality. But scientists in South Korea are reporting a significant advance toward the development of such devices.

Ji Hye Hong

Stretchable graphene electrode patterns transferred onto a silicon-based polymer.

In a paper in Nature, Jae-Young Choi of the Samsung Advanced Institute of Technology and Keun Soo Kim and Byung Hee Hong of Sungkyunkwan University and colleagues describe a technique for making stretchable thin electrodes out of graphene.

Graphene is a single-layer sheet of carbon atoms (the building block, in fact, of the graphite used in pencils) and has properties that make electronics engineers swoon. But making graphene sheets of a practical size has proved problematic.

The researchers used a process called chemical vapor deposition, in which methane gas mixed with hydrogen and argon is flowed over nickel foil at high temperatures, depositing carbon atoms from the methane on the nickel.

By cooling the foil quickly, just a few layers of graphene are obtained. And the graphene can be patterned by creating a pattern in the nickel first.

By etching away the nickel, the researchers were left with an ultrathin film of graphene that could be easily transferred to a different substrate, like flexible plastic.

In addition to being nearly transparent and having excellent electrical characteristics, the films are unaffected by bending or stretching. And the researchers say the process is scalable, so relatively large films can be made.