Researchers at Nokia and MIT's Microsystems Technology Laboratories are developing techniques to cut semiconductors' energy consumption by reducing their operating voltage levels. Their work may result in mobile electronic devices that better handle the taxing power demands placed on them by ever-expanding functionality.

Jamey Hicks, director of the Nokia Research Center, says the company has made leaps in developing chips that can operate at voltage levels below the normal thresholds required to switch individual transistor pairs on and off for regular operation.

Transistors inside semiconductors usually act like switches. Individual transistors move to an open or closed position depending on the charge applied to them. By reducing that voltage, the size of the openings of individual transistor gates is reduced, thereby cutting the volume of current flowing through the gates.

"It's like turning a water tap on only half way," Hicks says.

Those "subthreshold" transistors could reduce the energy consumption of chips to between a fifth and a tenth of typical levels. For semiconductors that use a lot of power, such as video-compression chips in cell phones, that reduction will boost devices' battery life, perhaps as much as three to 10 times normal, Hicks says.

Nokia research teams are analyzing areas for using subthreshold semiconductors, but commercialization of the chips is probably four to five years away.