There has been a breakthrough in making miniscule brushes that opens the way for bio-fuel cells that can power pace-makers, cochlear implants, and prosthetic limbs.

University of Georgia (UGA) chemist Jason Locklin and graduate students Nicholas Marshall and Kyle Sontag grew polymer brushes, made up of chains of aromatic molecules sometimes used as solvents, attached to metal surfaces as ultra-thin films.

Locklin said that molecular wires are actually polymer chains that have been grown from a metal surface at very high density. The structure of the film resembles a toothbrush, where the chains of conjugated polymers are like the bristles.

He further said, this technique gives the control to systematically vary polymer architecture, opening up the possibility for various uses in electronic devices such as sensors, transistors and diodes. The ultra-thin films are between five and 50 nano-metres - too small to see, even under a high-powered optical microscope, according to a UGA release.

The next step for Locklin is to develop appropriate applications. For example, his polymer brush technique might be used in a range of devices that interface with living tissue, such as biochemical sensors, prosthetic limbs, pace-makers or bionic ears. The film itself might be used in transistors - or in photovoltaic devices such as solar cells.

The research, funded by the Petroleum Research Foundation, was published in the June issue of Chemical Communications.