A team of Caltech engineers has succeeded in creating a fuel cell so small it could power an MP3 player but last many times longer. Led by Sossina Haile, the team made several technological breakthroughs, according to a Caltech press statement.
Currently, the team is collaborating with design experts to increase fuel efficiency. Applications of a finished design would be practically limitless, according to the team: laptop computers, television cameras, or even tiny military robots.
Haile, who was out of the country and could not be reached for comment, said in the release that the key breakthrough was a new way for the cell to keep its propane fuel hot enough to generate power. "Small fuel cells are challenging because it's hard to keep them at the high temperatures required to get the hydrocarbon fuels to react,' the press release reported her as saying. "(Normally) you have to use a lot of insulation to keep the cell hot. Adding insulation takes away the size advantage.'
Researchers at Caltech escaped this dilemma by burning tiny amounts of the propane within to keep the remaining fuel warm. Propane has the advantage of compressing easily and turning instantly to a vapor when released, though almost any hydrocarbon could work in a fuel cell.
According to Haile, two more advances turned this self-heating cell into something viable for a laptop or an iPod. First, the Caltech researchers came up with a design that could perform the necessary chemical reactions in a single chamber. Second, engineers at Northwestern developed catalysts that greatly increased the heat released by the fuel cell. Combining all three advances with a heat exchanger to lessen heat lost through exhaust, Haile said, "makes for a very simple and compact fuel-cell system.' |