23 Jan 2009 05:01:05
World's smallest fuel cell developed
A fuel cell shorter than a grain of rice has been developed, which researchers claim could be a precursor to models that replace batteries in mobile devices.
Chemical engineers at the University of Illinois set out to solve the problem of small scale fuel cell production.
The problem with creating small fuel cells is that they require a pump which at that scale uses more electricity than it generates.
"It's not practical to make a pump, a pressure sensor and the electronics to control the system in such a small volume," New Scientist quoted the university's Saeed Moghaddam as saying. "Even if they are magically made at that scale, their power consumption would probably exceed the power generated."
The device uses a membrane to let water into a chamber where it is evaporated and reacts with metal hydride to form hydrogen.
Once the gas is formed it puts pressure on the membrane, which stops the water from entering the chamber where the hydrogen reacts with electrodes to generate electricity.
As the electricity is consumed the pressure on the membrane eases allowing more water to enter the chamber.
Meanwhile, the council of Copenhagen, where the next round of talks to come to a global agreement to replace Kyoto will be held, plans to purchase hydrogen-powered cars.http://tinyurl.com/8l6w94