Mobile battery life could run months

Researchers at the University of Illinois have developed an ultra-low-power digital memory that is faster and uses 100 times less energy than currently used memory modules. Mobile devices that run for months rather than days without charging? Well, your wish may soon be granted - thanks to nanotechnology.

They believe the technology would significantly enhance battery life of portable devices, including mobile phones.

"I think anyone who is dealing with a lot of chargers and plugging things in every night can relate to wanting a cell phone or laptop whose batteries can last for weeks or months," said lead author and electrical and computer engineering professor Eric Pop.

The flash memory used in mobile devices currently stores bits as charge, which requires high programming voltages and is relatively slow.

Pop and his team lowered the power per bit to 100 times less than existing phase-change materials (PCM) memory by focusing on the size.

Rather than the metal wires standard in industry, they used carbon nano tubes - tiny tubes 10,000 times smaller than a human hair.

"The energy consumption is essentially scaled with the volume of the memory bit," said graduate student Feng Xiong, the first author of the paper.

"By using nano scale contacts, we are able to achieve much smaller power consumption," he added.

To create a bit, the researchers placed a small amount of PCM in a nano-scale gap formed in the middle of a carbon nanotube. They can switch the bit 'on' and 'off' by passing small currents through the nano tube.