Nanoscale fuel cells may be closer than we think thanks to an

first_imgWe live in a world of hand-held devices: iPods, cell phones, PDAs, pagers… the list of essential personal technology keeps expanding, and the natural response is consolidation. It’s rare these days to see a new cell phone that isn’t also a digital camera, and MP3 players can be integrated into just about anything. We’re just a short step away from universal, hand-held devices that combine communication, media, and entertainment into one slim package. What’s stopping us? In a word, power. Scanning electron microscope image of two individual electrodes. Copyright Kenneth Lux. Used with permission. Lux and Rodriguez found their fuel channels ready-made in a commonly available, porous alumina filter costing only about $1. The filter is riddled with neat, cylindrical holes only 200 nanometers in diameter, and was already being used at their lab as a template for the growth of nanowires. Lux hit on the idea of creating nanowires in a platinum-copper alloy, then dissolving the copper by soaking the filter in nitric acid. In place of a solid nanowire, each hole was left with a porous platinum electrode. The partially dissolved wires are structurally complex, as befits their random nature, and have an enormous surface area for their size. To build a fuel cell, they fill the pores with acid. A sheet of electrolyte-loaded filter paper (or polymer-electrolyte) is placed between two of the nano-electrode arrays to carry off the hydrogen ions. Electrodes can then be placed anywhere on the outer surface of the sandwich, allowing the electrical connections to be easily configured. Stacks of these fuel cell arrays can be connected in series or parallel, to provide higher voltage or current respectively.Of course, the result is hardly perfect. Lux estimates that only a third of the electrodes are active, and admits that there is a lot of room for improvement. Even this proof-of-concept prototype, however, has an energy capacity an order of magnitude higher than its two-dimensional lithographic counterparts! The price can’t be beat, either, with a total materials cost of only $200. “It’s a really simple method.” says Lux, “My power source [for making the nanowires] was a AA battery.”If fuel-cell technology can be perfected, we might be looking at a future of cheap, disposable battery packs for our favorite electronic gadgets. When your universal media manager runs out of energy, you’ll just run to the store and buy it a methanol sandwich! Citation: Template Synthesis of Arrays of Nano Fuel Cells, Kenneth W. Lux and Karien Rodriguez, Nano Letters 6, 2006by Ben Mathiesen, Copyright 2006 Fuel cell prototype. Copyright Kenneth Lux. Used with permission. Fiat Lux!Researchers Kenneth Lux and Karien Rodriguez, at the University of Wisconson, came up with an exciting new approach to the problem. Their method not only improves the performance of nano-scale fuel cells, but completely sidesteps the need for industrial-strength technology. “Even the best electrocatalysts, on a flat surface, give only hundreds of microamps per square centimeter. What you really want is … to increase the surface area by orders of magnitude.” Lux explains to, “To do this you need a three-dimensional structure.” Toyota to test solar panels for electric carslast_img

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