running on PEE <DON'T laugh...this is true>

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URINE BATTERY TURNS PEE INTO POWER
By John  Roach
National Geographic News
August 18, 2005

_http://tinyurl.com/a99c2_ (http://tinyurl.com/a99c2)

Urine Battery Turns Pee Into Power
John Roach
for National Geographic News
August 18, 2005

Before you next flush the toilet, consider this: Scientists in Singapore
have developed a battery powered by urine.

Researchers at the Institute of Bioengineering and Nanotechnology created
the credit card-size battery as a disposable power source for medical test
kits.=20



Scientists have been scrambling to create smaller, more efficient, and less
expensive "biochips" to test for diseases such as diabetes. Until now,
however, similarly small batteries to power the devices remained elusive.

Diagnostic test kits commonly analyze the chemical composition of a person'=
s
urine to detect a malady. Ki Bang Lee and his colleagues realized that the
substance being tested=8Burine=8Bcould also power the test.

"In order to address this problem, we have designed a disposable battery on
a chip, which is activated by biofluids such as urine," Lee wrote in an
e-mail to National Geographic News.

The research team describes the battery in the current issue of the Journal
of Micromechanics and Microengineering.

Daniel Kammen, director of the Renewable and Appropriate Energy Laboratory
at the University of California, Berkeley, said the technology is a welcome
innovation in a time of rising energy prices.

"All jokes [about] urine aside, what is needed are low-cost batteries. =8A" h=
e
said. "The other neat thing about this is the fact that it's basically a
biodegradable battery."

Urine Power=20

To make the battery, Lee and his colleagues soaked a piece of paper in a
solution of copper chloride and sandwiched it between strips of magnesium
and copper. This sandwich was then laminated between two sheets of
transparent plastic.

When a drop of urine is added to the paper through a slit in the plastic, a
chemical reaction takes place that produces electricity, Lee said.

The prototype battery produced about 1.5 volts, the same as a standard AA
battery, and runs for about 90 minutes. Researchers said the power, voltage=
,
and lifetime of the battery can be improved by adjusting the geometry and
materials used.=20

CONTINUED=A0 1 | 2 =A0Next >> (see website listed above)


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