This is from 2009, so you may have heard of it before, but it's a battery made out of a VIRUS! It's bioengineering at it's finest.

Researchers from MIT developed a regular lithium ion style battery. However, the traditional graphite anode and lithium ion cathode have been replaced by "conductive" viruses, and all the while providing the same power and energy capacitor as modern hybrid batteries.

The researches genetically engineered viruses to coat themselves in iron phosphate and then "grab" carbon nanotubes to form, essentially, a nano wire.

Lab tests show that the wires can be charged 100 times or more without losing any capacitance and charge. They hope to explore options of higher voltage and capacitance to be able to produce on a global market production scale.

The benefits of these wires are limitless: non toxic materials, harmless synthesis process, no harm to humans (the viruses attack bacteria), lightweight battery, connectability for multiple batteries to produce more power, and environmentally friendly. Furthermore, the applications of these wires and batteries are even more limitless, from hand held devices to cars and bigger vehicles.

This technology is very impressive and extremely applicable. I personally find it extremely interesting as it take something so small that people think as harmFUL and put it into a massive, up close, daily use that will be harmLESS. Truly remarkable, it is.

http://web.mit.edu/newsoffice/2009/virus-battery-0402.html