Berkeley Lab scientists have found a way to make harmless viruses harvest mechanical energy, which could then be used, say, to charge a phone as its owner walks along.
They've created a generator that produces enough current to operate a small liquid-crystal display. It harvests energy when the user taps a finger on a postage stamp-sized electrode coated with specially engineered viruses which convert the force of the tap into an electric charge.
The generator is the first to produce electricity by harnessing the piezoelectric properties of a biological material. It could replace the use of highly-toxic chemicals in current piezoelectric devices.
It could also lead to a simpler way to make microelectronic devices, as the viruses self-assemble into an orderly film.
"More research is needed, but our work is a promising first step toward the development of personal power generators, actuators for use in nano-devices, and other devices based on viral electronics," says Seung-Wuk of Berkeley Lab and UC Berkeley.
The M13 bacteriophage only attacks bacteria and is benign to people. It replicates itself by the millions within hours, so there's always a steady supply, and it's easy to genetically engineer.
When pressure is applied to the generator, it produces up to six nanoamperes of current and 400 millivolts of potential - about a quarter the voltage of a triple A battery.
"We're now working on ways to improve on this proof-of-principle demonstration," says Lee. "Because the tools of biotechnology enable large-scale production of genetically modified viruses, piezoelectric materials based on viruses could offer a simple route to novel microelectronics in the future."