BehindTheMedspeak: Urine–Powered Battery

Korean scientist Ki Bang Lee and his team at Singapore's Institute of Bioengineering and Nanotechnology (IBN) have developed a paper battery (above) that is small, cheap to fabricate, and uses the fluid being tested — in this case, urine — as the power source for the device doing the testing.

Talk about bootstrapping.

The work was published on August 15 in the Journal of Micromechanics and Microengineering.

Said Lee in a story on PhysOrg.com, "We are striving to develop cheap, disposable credit card–sized biochips for disease detection. Our battery can be easily integrated into such devices, supplying electricity upon contact with biofluids such as urine."

The battery unit is made from a layer of paper soaked in copper chloride and then sandwiched between strips of magnesium and copper.

This "sandwich" is then held in place by being laminated, which involves passing the battery unit between a pair of transparent plastic films through a heating roller at 120ºC.

When a drop of urine is added to the paper through a slit in the plastic, a chemical reaction begins, producing electricity.

The final product has dimensions of 60 mm x 30 mm and a thickness of just 1 mm (a little bit smaller than a credit card).

Using 0.2 ml of urine they generated a voltage of around 1.5 V, the amount of power generated by a AA battery.

Their biobattery lasted 90 minutes.

The current in the device comes from a chemical reaction in which substances in the urine produce a flow of electrons from the magnesium to the copper.

Lee foresees the device's use with specific biochips to create specific tests for glucose levels in people with diabetes or to detect food or water poisoning.

The scientist noted that his battery also works with saliva or blood.

I think this is simply sensational and potentially revolutionary.

The more you distance the nuts and bolts of medicine — testing and such — from the institutional structure and put it in the hands of the individual, the better will the individual fare in the world of health care.