Faster memories made of nanowires
Researchers at the University of Pennsylvania have developed self-assembling nanowires which will allow to access data 1,000 times faster than current technologies such as Flash memory. They've used nanowires made of germanium, antimony and tellurium which can switch between amorphous and crystalline structures -- the equivalent of 0's and 1's. The scientists say that their technology will use less space and power than current technologies. But more surprisingly, they add that their nanowires will be able to store data for 100,000 years. I really wonder how they can make such a claim.
You can see above several "elemental mapping images of an isolated nanowire showing uniform spatial distribution of germanium, antimony and tellurium elements obtained by energy dispersive x-ray spectroscopy (EDS) in scanning transmission electron microscope (TEM) mode. (Credit: Penn University) This research has been led by Ritesh Agarwal, an assistant professor in the Department of Materials Science and Engineering, and several colleagues of his research group.
So how these new memories were tested? "Tests showed extremely low power consumption for data encoding (0.7mW per bit). They also indicated the data writing, erasing and retrieval (50 nanoseconds) to be 1,000 times faster than conventional Flash memory and indicated the device would not lose data even after approximately 100,000 years of use, all with the potential to realize terabit-level nonvolatile memory device density. 'This new form of memory has the potential to revolutionize the way we share information, transfer data and even download entertainment as consumers,' Agarwal said. 'This represents a potential sea-change in the way we access and store data.'"
Here is why the Penn researchers decided to use phase-change nanowire memory. "Phase-change memory in general features faster read/write, better durability and simpler construction compared with other memory technologies such as Flash. The challenge has been to reduce the size of phase change materials by conventional lithographic techniques without damaging their useful properties. Self-assembled phase-change nanowires, as created by Penn researchers, operate with less power and are easier to scale, providing a useful new strategy for ideal memory that provides efficient and durable control of memory several orders of magnitude greater than current technologies."
And to whet our appetite, Agarwal added: "Imagine being able to store hundreds of high-resolution movies in a small drive, downloading them and playing them without wasting time on data buffering, or imagine booting your laptop computer in a few seconds as you wouldn’t need to transfer the operating system to active memory."
For more information, this research work has been published in Nature Nanotechnology as an advance online publication on September 17, 2007 under the name "Highly scalable non-volatile and ultra-low-power phase-change nanowire memory." Here is the beginning of the abstract. "The search for a universal memory storage device that combines rapid read and write speeds, high storage density and non-volatility is driving the exploration of new materials in nanostructured form. Phase-change materials, which can be reversibly switched between amorphous and crystalline states, are promising in this respect, but top-down processing of these materials into nanostructures often damages their useful properties. Self-assembled nanowire-based phase-change material memory devices offer an attractive solution owing to their sub-lithographic sizes and unique geometry, coupled with the facile etch-free processes with which they can be fabricated."
Please note that the above illustration comes from the supplementary info provided along with the above article.
Finally, if any of you has some additional information about the claim that these nanowire-based memories can last for 100,000 years, please drop me a note.
Sources: University of Pennsylvania news release, September 17, 2007; and various websites
You'll find related stories by following the links below.