Going for gold with nanotechnology

Collaborative nanotechnology research involving the University of Technology, Sydney has proved the value of gold as a vital component in the next generation of electronics.

Professor Michael Cortie of the UTS Institute for Nanoscale Technology has put the precious metal to work in a state-of-the-art device known as an ultra-capacitor, which generates power in electronic circuits and is already used in fields such as mobile communications and computing.

The aim of the research has been to improve upon existing designs, which are subject to significant operational problems, including a 'modest' capability for energy storage and operational inefficiencies due to internal heat generation.

Prof. Cortie and his South African collaborator Dr Elma van der Lingen, from Mintek in Johannesburg, have succeeded in designing and - in a world first - producing a new generation ultra-capacitor containing gold instead of the carbon used previously.

In the process they have demonstrated that gold-based devices can store up to six times as much energy as the standard 'old-fashioned' capacitor.

Their international project, partially funded by the World Gold Council in London, has contributed substantially to the Council's research program aimed at developing new industrial uses for gold.

As far as Prof. Cortie and Dr van der Lingen have been able to determine, this is the first time that an ultra-capacitor based on gold has been made anywhere in the world, although Professor Cortie points out that the idea has been mooted previously.

In developing the ultra-capacitor prototype, the researchers first used an intermetallic compound of gold and aluminium, known as purple glory. Subsequently they removed the aluminium, leaving a sponge of puregold.

"Gold seems rather an improbable choice compared to carbon," Prof. Cortie said. "But it turns out the electric power that can be efficiently drawn from a carbon-based ultra-cap is limited by the high internal resistance of such devices. Gold by contrast is a truly excellent electrical conductor.

"Additionally, carbon-based ultra-caps are not cheap, so including a fraction of a gram of gold in an ultra-cap is only slightly more expensive.

"We are now exploring the behaviour of these ultra-caps in order to identify what their competitive advantages might be. Because of the gold content we suppose that only rather small devices would ever be acceptable for consumer electronic applications, but we do have some ideas."

Item provided courtesy of UTS