Memory chip of future promises massive storage capacity
A hardy, heat-resistant, graphite-based memory device holds the potential of making massive amounts of storage available for computers, handheld media players, cell phones and cameras.world Updated: Nov 22, 2008 12:51 IST
A hardy, heat-resistant, graphite-based memory device holds the potential of making massive amounts of storage available for computers, handheld media players, cell phones and cameras.
Rice University researchers, who are currently developing the device, said the solid-state device takes advantage of the conducting properties of graphene and would have many advantages over today's state-of-the-art flash memory and other new technologies.
Graphene memory would increase the amount of storage in a two-dimensional array by a factor of five, said James Tour, who led the research team.
This is so because individual bits could be made smaller than 10 nanometres, compared to the 45-nanometre circuitry in today's flash memory chips.
Findings of the new research have been published online in the journal Nature Materials.
Being essentially a mechanical device, such chips will consume virtually no power while keeping data intact -- much the same way today's e-book readers keep the image of a page visible even when the power is off.
What distinguishes graphene from other next-generation memories is the on-off power ratio -- the amount of power a circuit holds when it's on, as opposed to off.
“It's huge - a million-to-one,” said Tour. “Phase change memory, the other thing the industry is considering, runs at 10-to-1. That means the 'off' state holds, say, one-tenth the amount of electrical current than the 'on' state.”
Current tends to leak from an “off” that's holding a charge. “That means in a 10-by-10 grid, 10 'offs' would leak enough to look like they were 'on.' With our method, it would take a million 'offs' in a line to look like 'on'," he said. “So this is big. It allows us to make a much larger array.”
While generating little heat itself, graphene memory seems impervious to a wide temperature range, having been tested from minus 75 to more than 200 degrees Celsius with no discernable effect, Tour said.
That allows graphene memory to work in close proximity to hot processors. Better still, tests show it to be impervious to radiation, making it suitable for extreme environments.
Tour said the new switches are faster than his lab's current testing systems can measure. And they're robust. “We've tested it in the lab 20,000 times with no degradation,” said Tour. “It's lifetime is going to be huge, much better than flash memory.”
Best of all, the raw material is far from exotic. Graphene is a form of carbon. In a clump it's called graphite, which you spread on paper every time you use a pencil.