Put a 747 In Your Phone
By Carlo Longino, Wed Oct 20 22:00:00 GMT 2004

Turbine technology adapted from jet aircraft engines might be the next possible power solution for mobile phones and other electronics.

US researchers are working on manufacturing microturbines made from silicon wafers. The technology, adapted from jet aircraft engines, has at least 10 times the energy per volume of fuel than today's standard lithium batteries, and are smaller than fuel cells, making it a contender to solve the growing power problems of mobile devices.

Engineers at the Georgia Institute of Technology have demonstrated that electricity can be generated by a turbine on a silicon wafer, and other teams have crafted prototype diesel combustion chambers made from silicon to power the turbines. The challenge now is to combine all the elements and manufacture them into a single stack of silicon wafers. The first likely application of the devices would be in military applications, where soldiers are often bogged down by the weight of the batteries they must carry to power the increasing amount of electronic devices they use.

Although the Georgia Tech researchers can already generate more than a watt of power -- enough, they say, to power a mobile phone or GPS receiver -- the technology isn't ready for prime time just yet. The prototypes run on diesel power, a material many users won't be too excited about carrying around. And an MIT version runs for 10 or more hours on a container of fuel the size of a D battery, which isn't exactly small. The turbine assembly itself is small, about a fourth the size of a typical handset battery, but whatever space and weight are saved there might be offset by fuel.

Another tiny problem from the tiny gadgets: the turbines also shoot out a stream of hot exhaust gas, making them a dangerous proposition for users' pockets.