Electrical wires inspired by bacteria

Researchers of the University of Antwerp, the University of Hasselt and Delft University of Technology discovered that centimetre-long bacteria from the seafloor contain fibres that are comparable to copper electronic wires, which could lead to bio-based cables.

More and more devices are running on electricity these days, and it is hard to imagine our lives without it, even if it was only discovered in the nineteenth century. Discovered by humans, that is, because recently discovered bacteria have been producing electrical networks for a great deal longer.

The bacteria, called cable bacteria, are a fraction of a human hair in with, but several centimetres long and consist of thousands of cells in a row. The bacteria were only discovered seven years ago at the seafloor.

Initially, it seemed that the cable bacteria were generating and conducting electrical currents running through the seafloor, but this was never proven until now. The team of biologists, chemists and physics extracted a single bacterial filament out of the seafloor and attached it to a custom-made setup with tiny electrodes. The researchers were able to send high currents through the material, comparable to copper wiring of our household appliances.

All known biological materials, be it proteins, carbohydrates, lipids or nucleic acids, are extremely poor in terms of electrical conduction, so the conductivity of the cable bacteria is remarkable.

We currently use three types of conductive materials in electronic materials, metals, inorganic materials and organic materials. With the discovery of cable bacteria’s conductivity, a fourth could one day be added to that, if we manage to replicate the fibrous structure. Using a biobased material in electronic could mean biodegradable electronics, reducing the problem of e-waste, or they could be applied in health care. Perhaps in a few years, we could all be walking around with smartphones equipped with conductive wiring of bacterial origin.

The study is part of a larger project about microbial electricity. More information you can find here.

Photos: UAntwerp, UHasselt, TU Delft