Microchip-sized generating plant could power portable devices
A series of three centimetre by three centimetre microchips, fuelled by small cartridges of methanol, could be used to produce hydrogen to power portable electronic devices such as laptop computers for up to ten hours, five times longer than standard rechargeable batteries.
The minute power generator is being developed by scientists at Lehigh University in Bethlehem, Pennsylvania, in the United States, and currently only produces a small amount of hydrogen, but this is sufficient to demonstrate that the project is feasible, says the University. The device uses the channels that normally transmit electrical current in order to carry reagents to fuel the generating plant housed in the chip’s reformer. This is heated by electricity, and the resulting reaction produces hydrogen. “About 10 years ago people started thinking, ‘can we take the same fabrication methods for silicon chips and instead of using them for electronics, use them for something else?’,” said Mayuresh Kothare, Assistant Professor of Chemical Engineering.
“At Lehigh our chip-based micro-chemical plant will take a reagent, such as methanol, or a hydrocarbon, like diesel or gasoline, and carry it to a tiny reactor to produce hydrogen,” said Kothare. “We have already produced hydrogen and have been able to get the reagents into the reactor to carry out the necessary reaction.” The hydrogen can then be collected in a miniature fuel cell which would power an electronic device, claim the researchers.
While the researchers admit that one chip alone cannot power a laptop computer, Kothare says that by wrapping up scores of the micro-plants together, known as ‘numbering up’, enough power could be produced to operate a wide variety of electronic devices. The technology would not face the problems of rechargeable batteries which can only be recharged a limited number of times (see related story), and instead of having to stop in order to recharge batteries, operators would merely have to insert a new fuel source.
However, challenges still remain before the device is fully developed, including the problem of how to get the reagents into the micro-capillaries. “Think of piping in your own house,” said Kothare. “You can buy standard fittings but there are no standard fittings for the chip plant and there are no standardized pipes. To get the reagents in is a whole world of its own. You don’t know how much will leak or vaporize or if it is sealed tightly.”