MIT researchers have made progress developing a tiny gas-turbine engine using processes borrowed from computer chip fabrication. The idea is that compared to batteries of the same weight, these coin-sized engines would power laptops, cell phones, and other mobile devices for much longer. "Big gas-turbine engines can power a city, but a little one could 'power' a person," said professor Alan Epstein of the Department of Aeronautics and Astronautics. So far, the MIT team has built all of the components. The next step is to integrate them into a complete system. Like integrated circuits, the components are produced en masse on a large silicon wafer and then cut apart. From the MIT News Office:
The MIT team has now used this process to make all the components needed for their engine, and each part works. Inside a tiny combustion chamber, fuel and air quickly mix and burn at the melting point of steel. Turbine blades, made of low-defect, high-strength microfabricated materials, spin at 20,000 revolutions per second — 100 times faster than those in jet engines. A mini-generator produces 10 watts of power. A little compressor raises the pressure of air in preparation for combustion. And cooling (always a challenge in hot microdevices) appears manageable by sending the compression air around the outside of the combustor.
"So all the parts work…. We're now trying to get them all to work on the same day on the same lab bench," Epstein said. Ultimately, of course, hot gases from the combustion chamber need to turn the turbine blades, which must then power the generator, and so on. "That turns out to be a hard thing to do," he said. Their goal is to have it done by the end of this year.
Link to MIT press release, Link to my related article from Small Times, January 2002, about tiny fuel cells, microturbines, and "The Power of Small Tech"
