London, Nov 23 : Computers, handheld media players, cell phones and cameras, will soon have massive amounts of storage, all thanks to researchers at Rice University who have developed a new type of memory using a strip of graphite only 10 atoms thick as its basic element.
In the study, Rice professor James Tour and colleagues have described a solid-state device that harnesses the conducting properties of graphene.
In Tour's opinion, such a device would score over today's state-of-the-art flash memory and other new technologies.
He said that graphene memory would increase the amount of storage in a two-dimensional array five times, as individual bits could be made smaller than 10 nanometers, compared to the 45-nanometer circuitry in today's flash memory chips.
The new switches can be controlled by two terminals instead of three, as in current chips. Tour said that two-terminal capability makes three-dimensional memory practical as graphene arrays can be stacked, multiplying a chip's capacity with every layer.
Originally being 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 juice a circuit holds when it's on, as opposed to off.
"It's huge - a million-to-one. 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," Nature quoted Tour as saying.
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'. So this is big. It allows us to make a much larger array'' he said.
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, said Tour.
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.
According to Tour, the technology has drawn serious interest from industry. He said it's possible to deposit a layer of graphene on silicon or another substrate by chemical vapor deposition.
"Typically, graphene is very hard to think about fabricating commercially, but this can be done very easily by deposition. The same types of processes used right now can be used to grow this type of graphene in place," he said.
The study is available online in Nature Materials.