Viruses act as tiny piezoelectric generators

Viruses, tiny chunks of protein and nucleic acid, have long plagued mankind and its evolutionary ancestors before it. But thanks to the wonders of modern genetic engineering, researchers believe they have finally been able to instill a beneficial purpose in these deadly pests.

I. From Pest to Power

A team of researchers at Lawrence Berkeley National Laboratory -- one of 16 U.S. Department of Energy (DOE) national laboratories -- has created a special breed of virus that undergoes self-nanoassembly to form tiny piezoelectric generators -- machines which harvest mechanical energy (vibrations or pressure) to directly produce electricity.

The special "bug" is the M13 bacteriophage, a rod-shaped virus that only infects bacteria (such asE. coli bacteria)-- not humans.

Faculty researchersSeung-Wuk Lee, Ramamoorthy Ramesh, and Byung Yang Lee selected the virus due to its tendency to self-assemble into nanofilms, given its rod-like shape. The viruses tightly pack "like chopsticks in a box" and are easy to grow by the millions given a small supply of host bacteria.

II. Refining the Virus

But the effect was too weak to be of use. So the researchers spliced a quadruplet of negatively charged amino acids into one of the coat proteins. The results was a larger voltage gradient across the coat. The researchers also tested stacking films of the modifed viruses to see how thick they could layer the viruses in order to get the maximum effect.

When pressure was applied to the film a 400 millivolt, 6 nanoampere current was put off. That's about a quarter of the voltage of an AAA battery, albeit at a far smaller current. Still it was enough to power a '1' to show up on a low-power liquid crystal display.

Continue reading here:
Berkeley Trains "Harmless" Viruses to Harvest Human Kinetic Energy