www.theregister.co.uk/2005/08/15/pee-powered_battery/

Scientists invent pee-powered battery

By Lucy Sherriff
Published Monday 15th August 2005 11:41 GMT

Researchers in Singapore have developed a paper battery that is powered by urine. Despite sounding gloriously silly, the breakthrough promises a cheap and disposable power source for home health tests for things like diabetes.

Research investment into developing smaller and cheaper chips to process information in disposable health tests has been significant, but they were still reliant on an external power source. The researchers at Singapore’s Institute of Bioengineering and Nanotechnology (IBN) think they have overcome this problem.

The battery is composed of paper, soaked in copper chloride, sandwiched between layers of magnesium and copper. The whole thing, once laminated in plastic, is just a millimetre thick, and 6cm by 3cm in size.

The researchers report that with just 0.2 millilitres of urine the battery will provide around 1.5 volts, with a maximum power output of 1.5 milli-Watts. The performance varies according to the geometry of the battery, and the materials used.

Dr. Ki Bang Lee, lead researcher, sees a big market for the battery. He argues that it could easily be integrated into biochip systems for "healthcare diagnostic applications", making it much easier for people to manage their own healthcare, only going to the doctor when absolutely necessary.

Why stop there?  I could piss-charge my Prius when I drink Mtn. Dew.