Ultra low power memory could extend battery life

ENGINEERS at the University of Illinois have developed digital memory technology that uses 100 times less power than similar memory.

Flash memory found in mobile phones today stores bits as charge, and this requires high voltage to carry out the task. The industry has looked for an alternative in the form of phase-change materials (PCM). These are faster but require more power for overcoming the resistance of the material, which is switchable.

The reason engineers have taken this technology and reduced the power per bit by 100 times is down to the size. Instead of using orthodox metal wires, the researchers used carbon nanotubes, which are 10,000 times smaller than a human hair and the smallest known electrical conductors.

Using nanotubes means that bits can be switched on and off by passing only a small amount of electrical current. Professor Eric Pop said, "They are better than any metal at delivering a little jolt of electricity to zap the PCM bit."

Nanotubes are also not vulnerable to degradation that is a problem with existing metal wire technology and are immune to accidental erasure of data from scanners and magnets.

The reason memory is so important in the struggle to extend battery life is that mobile phones are being used more and more for computing purposes involving large data files, such as when you run an application, store an mp3 file or stream a video.

Mobile phones aren't where this technology's application will end, either. It could apply to anything that uses a battery and even stretch into uses in data centres. The team isn't stopping at the power reduction factor of 100 and they predict that they can continue to "lower power by at least another factor of 10," said Pop. µ