BIOLOGICAL fuel cells are closer to reality thanks to the success of a team of American researchers.
The University of Georgia researchers have developed a successful way to grow “molecular wire brushes” that conduct electrical charges.
This is regarded as a first step in developing biological fuel cells so small that they could power pacemakers, ear implants and prosthetic limbs.
The molecular wires are actually polymer chains that have been grown from a metal surface at very high density.
The ultra-thin films are between five and 50 nanometres – too small to see even under a high-powered optical microscope.
It is difficult to harness a fuel source in the body, such as glucose, for use in biofuel cells that could replace the need for batteries in an implanted device.
And while humans have enzymes in the body that do a good job of converting chemical energy into electrical energy, they are apparently not much good for this micro-fuel-cell application because they have natural protective insulating layers that prevent good electron transport from active site to electrode.
The hope of the Georgia scientists is that their molecular wires will provide a better conduit for charges to flow.
Even though they admit to not yet understanding all of the fundamental physics involved in how electrical charges move through organic materials, their next step is to find appropriate applications.
This is where the idea of using the polymer brush technique in a range of devices that interface with living tissue comes in.
The film itself might also be used in transistors – or in photovoltaic devices such as solar cells.