Are all viruses bad?
Perhaps not. Viruses are capable of making environment-friendly batteries, at least as good as commercial batteries!
But in fact the M13 strain of virus (harmless) has been trained to make lithium ion batteries that really work.
Inside a lithium ion battery, lithium ions move from the anode to the cathode (+ve to –ve), forcing electrons to go in the opposite direction around the external circuit. Re-charging just requires this process to run in reverse for a while.
But the manufacture of popular lithium ion batteries need highly reactive components, aggressive solvents and high temperatures, making them environmentally unfriendly to produce and dispose of. Handling lithium is also dangerous.
Now Angela Belcher and her team at MIT have persuaded a virus M13 to take over the process and build a 3-volt lithium ion battery. The viruses become coated in metal and create nanowires, resulting in conductive pathways for electrons and the lithuim. The final product turned out to be as good as the best commercial batteries!
But—here’s the big difference—compared to the conventional batteries the biologically-grown batteries are environmentally much more friendly: the materials can now be made a room temperature or on ice and without harsh solvents. Evidently, it’s a pretty simple process and doesn’t require fancy equipment.
Already these batteries have proven as powerful as conventional batteries. But there is every reason to expect them, ultimately, to outperform existing commercial batteries. Belcher’s team is now looking to use materials that will work at higher voltages and more storage capacity.
Wonder what that will do for the energizer bunny? Will it need vaccine shots to keep going… and going… and going?
[from New Scientist, Apr 11- 17, 2009, p. 18]