US team create carbon nanotube ultra-memory
Chips to last a billion years, hold trillion bits/sq in
US researchers have demonstrated a form of nanotube archival memory that can store a memory bit for a billion years, and has a theoretical trillion bits/square inch density.
The researchers at the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California (UC) Berkeley were led by physicist Alex Zettl. They built a prototype device based on a nanoscale iron particle, about 1/50,000th the width of a human hair, moving along a carbon nanotube like a shuttle.
The nano-structure was created in a single step by pyrolysis of ferrocene in argon at 1,000 degreees C. The created nanotube elements are dispersed in isopropanol ultrasonically and deposited on a substrate with electrical contacts applied to the ends of the nanotube. The researchers say these steps are compatible with common semiconductor manufacturing techniques.
By applying an electric current, the iron particle shuttle could be made to move inside the nanotube either away from or towards the current source. When the current was turned off the particle was, as it were, frozen in position. By applying the current in a timed pulse the particle could be made to move a fixed 3nm distance in steps. The speed of movement could be altered by varying the applied bias voltage.
The researchers say that placing the shuttle either side of the mid-point along the length of the nanotube can constitute a digital one or zero. A transmission electron microscope showed the shuttle moving - there is a video showing this accessible here. In a practical device the shuttle position could be read via detecting the axial electrical resistance of the nanotube by small voltage pulses. This is sensitive to the physical location of the enclosed nanoparticle shuttle and the pulses do not alter the state of the shuttle.
Calculations were made based on how far the shuttle would have to move at room temperature, with no applied voltage, before its position altered sufficiently for the data value to be changed, and how long this would take. The researchers calculated it would take 3.3 × 10 to the power 17 seconds and conclude that they have demonstrated the feasibility of an archival storage memory element with a billion year lifespan.
Other calculations suggest a complete archival chip could store a trillion bits in a square inch in this way. Fascinating stuff, but any practical usage is still many, many years away.
The research is described in a publication called Nano Letters, in a paper called Nanoscale Reversible Mass Transport for Archival Memory. ®
I for one welcome our Nano Overlords..
With there Carbon Nanotube Railguns...
Hmm.. wonder what velocity these projectiles can reach by accidental static discharge???
Great - That means I can now store my music long enough for it to enter the public domain!
The smaller it is, the easier it is to go wrong
I hope they take consideration of background radiation?
The smaller they make the memory cell the easier it is for a single particle to alter a whole bit.
I'd love to see what a bolt of ordinary static electricity would also do to this device.
@ Graham Bartlett
I think you've missed the standard caveat that this *years* and *years* away from being practical.
I agree that this is meant for long term storage and to answer you question about stability, you could always shield the chip such that you limit the amount of electric noise exposure, except to the electric currents that you want.
If they can shrink the length of the tube, increase the sensitivity of their measurements, it will be faster.
Imagine if they can, when writing, 'shoot' the metal particle to one wall or the other. Then you have you 1/0 state easily read. My guess is that its the length of tube that helps give it the really long data lifespan. If they shorten it, will it at least last 1000 years? If so, and Moore's law kind of holds, they can probably figure out how to make it small, fast and last a billion years with a couple of decades.
Too bad anyone trying to read it in a billion years will probably lack the technology...
Off the Rails for a Roam ...... into Contemporary Phish Phormations
""The nano-structure was created in a single step by pyrolysis of ferrocene in argon at 1,000 degreees C. The created nanotube elements are dispersed in isopropanol ultrasonically and deposited on a substrate with electrical contacts applied to the ends of the nanotube."
Straight forward enough! Thanks for making that so clearly understandable!" .... By Steve Swann Posted Tuesday 9th June 2009 06:57 GMT
Sounds like Python on Sticky Speed and Sweet Ruby Red Wine, Steve.
And QuITe Perfect for whenever the Future is Steered by what we do Today with what we know of Tomorrow, with the Past only a Never to Return Proxy Memory Occupying the Minds of the Slow-Witted as they are EduTained Sublimely to a Higher Beta Operating Standard.