Scientists have made a breakthrough that could lead to tiny devices that harvest electrical energy from the vibrations of everyday tasks such as shutting a door or climbing stairs.
The team from the US Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) have developed a way to generate power using harmless viruses that convert mechanical energy into electricity.
They tested their approach by creating a generator that produces enough current to operate a small liquid-crystal display.
It works by tapping a finger on a postage stamp-sized electrode coated with specially engineered viruses. The viruses convert the force of the tap into an electric charge.
Their generator is the first to produce electricity by harnessing the piezoelectric properties of a biological material. Piezoelectricity is the accumulation of a charge in a solid in response to mechanical stress.
The milestone also points to a simpler way to make microelectronic devices. That's because the viruses arrange themselves into an orderly film that enables the generator to work. Self-assembly is a much sought after goal in the finicky world of nanotechnology.
"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," said Seung-Wuk Lee, a faculty scientist in Berkeley Lab's Physical Biosciences Division and a UC Berkeley associate professor of bioengineering.
He conducted the research with a team that includes Ramamoorthy Ramesh, a scientist in Berkeley Lab's Materials Sciences Division and a professor of materials sciences, engineering, and physics at UC Berkeley; and Byung Yang Lee of Berkeley Lab's Physical Biosciences Division.
The piezoelectric effect was discovered in 1880 and has since been found in crystals, ceramics, bone, proteins, and DNA. It's also been put to use. Electric cigarette lighters and scanning probe microscopes couldn't work without it, to name a few applications.
But the materials used to make piezoelectric devices are toxic and very difficult to work with, which limits the widespread use of the technology.