Monday, December 29, 2008

Graphene memory device at Rice University

James Tour and colleagues at Rice University have demonstrated a switch (described in Nature Materials) composed of a layer of graphite about ten atoms thick. An array of such switches can be built in three dimensions, offering very high densities of storage volume, far exceeding what we now see in hard disks and flash memory USB widgets. The switch has been tested over 20,000 switching cycles with no apparent degradation. The abstract of the Nature Materials article reads:
Transistors are the basis for electronic switching and memory devices as they exhibit extreme reliabilities with on/off ratios of 104–105, and billions of these three-terminal devices can be fabricated on single planar substrates. On the other hand, two-terminal devices coupled with a nonlinear current–voltage response can be considered as alternatives provided they have large and reliable on/off ratios and that they can be fabricated on a large scale using conventional or easily accessible methods. Here, we report that two-terminal devices consisting of discontinuous 5–10 nm thin films of graphitic sheets grown by chemical vapour deposition on either nanowires or atop planar silicon oxide exhibit enormous and sharp room-temperature bistable current–voltage behaviour possessing stable, rewritable, non-volatile and non-destructive read memories with on/off ratios of up to 107 and switching times of up to 1 μs (tested limit). A nanoelectromechanical mechanism is proposed for the unusually pronounced switching behaviour in the devices.
It will be several years before memories based on these switches are available for laptops and desktops, but it's a cool thing. To my knowledge, the mechanism is not yet known, so there may be some interesting new science involved as well.


IV said...


At one time you were working at nanorex. But now I see that you have moved to MAssachussets.
Just looking to get more information about Nanorex. Is the company still fine? I don't see any new product releases on their website.

Will Ware said...

When I worked for Nanorex I was working from Massachusetts as Nanorex has/had a distributed workforce. Due to the economic downturn, I believe Nanorex has had to lay people off. I haven't been in touch lately and don't know exactly what's going on. I think there is work continuing on a volunteer basis. I hope that when the economy picks up again, Nanorex will resume its earlier level of activity. They're good folks doing good work.