The world's smallest fuel cell, measuring just 3mm x 3mm x 1mm (roughly 0.1 inches square by 0.04 inches tall), has been built by scientists at the University of Illinois Urbana-Champaign. The tiny cell is able to produce about 1 milliamp at 0.7 volts for 30 hours.
The cell is so small that it simply eliminates some of the components typically found in larger fuel cells.
"It's not practical to make a pump, a pressure sensor, and the electronics to control the system in such a small volume," says Saeed Moghaddam at the University of Illinois at Urbana-Champaign. "Even if they are magically made at that scale, their power consumption would probably exceed the power generated."
So with this fuel cell, there is no fuel tank, for example. The tiny cell gets the necessary moisture for its operation from water vapor in the air. To regulate the system, as water vapor enters the chamber and reacts to produce hydrogen, the pressure of the hydrogen closes a membrane which blocks more vapor laden air from entering until the hydrogen pressure has been reduced again.
As more tiny electronic devices are developed, providing power for them can start to become an issue. Many cell phones weigh less than the batteries that are attached to them to provide them with power. Instead of needing heavy power supplies for small electronics components, this type of very small fuel cell may play a role in providing the necessary power for tiny distributed electronics applications in the future. And, developments in these systems may also lead to new developments in fuel cell power systems to replace batteries in consumer electronics devices such as portable phones and laptop computers.
via: New Scientist Tech
written by Mark Bartosik, February 11, 2009
written by duncan, February 12, 2009
written by Fred, July 16, 2009
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