Developments with nanowire film

Researchers at Harvard University have demonstrated that they can apply a film of silicon nanowires to glass and plastic. The development could pave the way for futuristic consumer electronics such as disposable computers and optical displays that can be worn in clothes or contact lenses.

Although a single nanowire is one thousand times smaller than the width of a human hair, it can carry information up to 100 times faster than similar components used in current consumer electronic products, claim the researchers.

Scientist have already demonstrated that these tiny wires have the ability to serve as components of highly efficient computer chips and can emit light for multicolour optical displays. But they have had difficulty until now in applying these nanowires to everyday consumer products, says Charles M. Leiber, PhD head of the research project and a professor of chemistry at Harvard.

"As with conventional high-quality semi-conducting materials, the growth of high-quality nanowires required relatively high temperature," explains Leiber. "This temperature requirement has - up until now - limited the quality of electronics on plastics, which melt at such growth temperatures."

By using a 'bottom-up' approach, which involves assembly of pre-formed nanoscale building blocks into functional devices, a film of nanowires can be applied to glass or plastics long after growth, at room temperature.

Using a liquid solution of the silicon nanowires, the researchers have demonstrated that they can deposit the silicon onto glass or plastic surfaces - similar to applying the ink of a laser printer to a piece of paper - to make functional nanowire devices.

They also showed that nanowires applied to plastic can be bent or deformed into various shapes without affecting performance.