Carbon nanotubes have been proposed as solutions to a host of modern technical problems, from space elevators to pin-point accurate drug delivery. But a more viable role for the 'tubes is as a computer memory storage device. And a Finnish research group has created a nanotube memory array that's 100,000 times faster than any made before.
The team used single-walled carbon nanotubes, which they configured to act as field-effect transistors (FETs). The resultant transisors store electrical energy for about 150,000 seconds--around two hours--and thus can act as a digital storage medium much like a NAND flash cell. The write/erase time for the nanotube memory is around 100 nanoseconds, and can be repeated around 10,000 times.
NAND flash has typical write/erase times only slightly faster, and have write/erase lifespans of between 100,000 and 1 million cycles. These are commercially optimised products though, and the nanotube memory is still very much a first-stab, lab-produced technology. Remember, the very first semiconductor transistor (pictured here) was jury-rigged and a couple of million times larger than our current technology.
Nanotube memory may one day supercede semiconductor flash memory due to its potential cheapness, reduced component size and favorable electrical characteristics. They also exhibit resistance to environmental effects like heat and radiation, which could make them ideal for space-based devices.
"The fast memory operation we have demonstrated could potentially also be realized using other carbon materials, such as carbon-nanotube bundles or graphene," according to team member Päivi Törmä of Helsinki University. And they're confident the technology can be optimized further by increasing the storage time, which is currently very short.