SKIRMISHER

Batteries of the future, if people like Alan Epstein would have their way, will be gas turbines miniaturized into the size of a quarter — each of which could fire your laptop for about 30 hours.

Thanks to a field of technology called micro-electro-mechanical systems (MEMS), Epstein and his friends have successfully created working prototypes of these really tiny “rocket engines.”

Made in the same way as the micro-rocket, its tiny silicon turbine blade spins at 20,000 revolutions per second (that’s 100 times faster than a jet engine’s turbine) and can generate 10 watts of power. Because of the turbine’s small size, most of the space in a laptop “battery” could hold fuel, giving it 5 to 10 times the life of current lithium-ion batteries. The fuel can be almost anything from hydrogen to natural gas to jet fuel, and it could be refueled quickly by swapping out a disposable fuel cartridge or refilling it like a lighter.

“The battery application is just tremendous,” says Xin Zhang, who left Epstein’s group in 2002 to start a MEMS research lab at Boston University. Aside from the commercial possibilities, the military has a keen interest in long-lasting portable power for its increasingly electronics-laden soldiers. The U.S. Army Research Laboratory funded Epstein’s work on the micro-turbine.

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