Scientists at the United States Department of Energy’s Lawrence Berkeley National Laboratory have developed a way to generate electricity using the piezoelectric ability of harmless viruses to convert mechanical energy into electricity.
The researchers built a generator with a postage stamp-sized electrode and based on a small film of specially engineered viruses.
When a finger tapped the electrode, the viruses converted the mechanical energy into electricity.
Materials that can convert mechanical energy into electricity are known as "piezoelectric".
"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.
This is said to be the first device to produce electricity by harnessing the piezoelectric properties of a biological material. Most existing piezoelectric devices are toxic and difficult to work with, limiting the widespread use of the technology.
The scientists worked with thin films of the piezoelectric virus M13 bacteriophage. They increased its piezoelectric ability through genetic engineering, adding four negatively charged amino residues to one end of the proteins that coat the virus. The residues increased the charge difference between the proteins’ positive and negative energy, boosting the voltage of the virus.
The scientists further enhanced the system by stacking the virus films on top of each other. A stack 20 layers thick was found to have the strongest piezoelectric effect.