We normally view viruses as pesky things that give us runny noses and headaches and won't even go away with the help of antibiotics.
But it looks like they can be helpful too: Scientists at the Department of Energy's Lawrence Berkeley National Laboratory have been able to harness viruses so that they generate enough electricity to power a small LCD display.
The breakthrough points to a future in which we can, for instance, power our phones as we walk witha small generator embedded in the sole of our shoes, or otherwise gather energy from everyday motions such as closing doors or walking up stairs.
So how does it work exactly?
How the viral electrode works
The short story is that the Berkeley Lab scientists took a postage stamp-sized electrode and coated it with a harmless, specially engineered virus that, when tapped, takes the energy of that tap and turns it into electricity.
The slightly longer story begins with the basic principle behind the electrode, which is nothing new: Called the piezoelectric effect, it was discovered in 1880 and is the way that certain materials gather an electric charge when they feel pressure from, say, a squeeze or press. Materials such as crystals, ceramics, bone, proteins and DNA are naturally piezoelectric. Some the devices that use piezoelectricity are electric cigarette lighters and scanning probe microscopes.
What is new is that the virus helps us with an old problem: It's hard to make piezoelectric devices, because the materials normally used to build them are generally toxic and difficult to use.
Also, at nano scales, it's an incredible help to have something that basically self-assembles. Like a virus. As the Berkeley Lab scientists, led by Seung-Wuk Lee, found out, they naturally arrange themselves into an orderly film that helps the generator work.
About the virus
Don't worry -- we won't be catching colds from powering our electronics: The virus, M13 bacteriophage, only attacks bacteria and won't harm people.
It replicates itself by the millions within hours, which basically creates a steady supply. It's easy to genetically engineer. And the rod-shaped viruses naturally orient themselves into well-ordered films, just like chopsticks in a box.
And, most importantly, it's piezoelectric. The scientists discovered this by applying an electrical field to a film of M13 viruses and noting that proteins that coat the viruses twisted and turned in response—evidence of the piezoelectric effect. The scientists then increased the virus's piezoelectric strength by boosting the voltage and stacking 20 layers of virus on top of each other. That size of a stack creates the strongest piezoelectric effect.