Technophiles who have been dreaming of mobile devices that run longer on lighter, slimmer batteries may soon find their wish has been granted.
University of Illinois engineers have developed a form of ultra-low-power digital memory that is faster and uses 100 times less energy than similar available memory. The technology could give future portable devices much longer battery life between charges.
Led by electrical and computer engineering professor Eric Pop, the team will publish its results in an upcoming issue of Science magazine and online in the March 10 ScienceExpress.
“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 Pop, who is also affiliated with the Beckman Institute for Advanced Science and Technology at Illinois.
The flash memory used in mobile devices today stores bits as charge, which requires high programming voltages and is relatively slow. Industry has been exploring faster, but higher power phase-change materials (PCM) as an alternative. In PCM memory a bit is stored in the resistance of the material, which is switchable.
Pop’s group lowered the power per bit to 100 times less than existing PCM memory by focusing on one simple, yet key factor: size.
Rather than the metal wires standard in industry, the group used carbon nanotubes, tiny tubes only a few nanometers in diameter — 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 nanoscale contacts, we are able to achieve much smaller power consumption.”