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Carbon Nanotube Memory on the Way
Cyberherbalist writes "Nantero, a nanotechnology company, is expecting prototypes of products using NRAM technology (nanotube-based, non-volatile random access memory) to be available in 2006. In the article at nature.com, it says that 'the company has succeeded in making circular wafers, 13 centimetres in diameter, that hold 10 gigabits of data.' And they are ten times faster than 'flash' memory."
For one, it's first-gen stuff. It will likely gain density quickly in the future. Also, don't forget this is basically NVRAM: way faster than a hard-drive, and way more permanent than DRAM. It fills a unique niche and cannot directly be compared to or replace either of the two. (Well, it could replace hard drives, if it shrunk enough). The day is coming (slowly) when the primary storage on any computer system will probably be some sort of nonvolatile solid-state device. Hard drives with spindles will be for bulk data (music, movies, documents), while the OS goes on the nonvolatile ram which is neccesarily much smaller in size, but more reliable and faster to access. You can do things that way now under Windows or Linux by buying a 1-4 GB-ish solid state flash disk for your root disk (or C: drive) and then putting in a large normal hard drive for all your bulk data, but current SSD technology is overpriced and suffers from various little problems, both of which make it impractical for mass deployment even if the OS vendors put more thought into supporting the setup.
11*43+456^2
I wonder if you saw this one? : Defective carbon nanotubes
Anyone remember 'holographic' storage that was going ti give TB's in something the size of a sugar cube, or all the other similar technologies touted over the last 10 years. They all came to nothing, we are still stuck with slow HDD's and flash technology. 10 years from now things will be much the same, we will have even bigger, marginally fast HDD's.
That atom chip corporation is a hoax
7 gigaherz 64 bit processor, 2 terabytes flash hard drive in a laptop? sure...
For one, it's first-gen stuff. It will likely gain density quickly in the future.
It may gain density, but gain little in reliability. I have a Ph.D. in solid state physics, so I should respond. The carbon nanotubes bend to make connect with an electrode, so something moves. This is usually a bad sign for long-term reliability. Ask telecom technicians if they would like to replace their solid state transistor-based switches with moving switches. Their answer will be that these moving parts wore out.
This memory might not improve to the point that it becomes more reliable than your present NVRAM.
It is very easy for a scientist to produce one working device in the lab. We call these hero devices. The rest of the world does not know this. When engineers get ahold of these claims, though, they tear them up, since the process might not be cheap, reliable or scaleable.
So yes, it might get better, but I wonder if this group and the related scientist have invented new physics. Have they fundamentally changed the way mechanical switches make contact, the way electrons move and are held in capacitors, and the way domains set up in magnetic memory? I think not. I think this is a step backwards towards old mechanical swithces made smaller and reliable memory made unreliable.
Here's a link to news from year 2003 where they accounced it:
http://www.newscientist.com/article.ns?id=dn3838
See Nantero's press releases; they announced their 10Gbit wafer in May 2003. Their partnership with LSI Logic isn't news either, that was announced June 2004. The fact that they're still signing new partnerships on a steady basis tells me this technology is not a dead-end (yet).
-- *My* journal is more interesting than *yours*...
10 gigabits in a 13cm diameter wafer? Does this really sound that good to anyone? I mean a little flash card is like 3cm wide and holds a gigaBYTE. This wafer holds 10gigabits/8bits = ~1.2 gigabytes. Harddrives? Assuming you have a bunch of these wafers for "platters" the size would still be pretty limited.
Indeed. I am a materials researcher (a very young and uneducated one however), and "movement" may have several definitions... in a paperclip for example, bending it back and forth inches crystal planes over one another until dislocations pile up and the whole thing is too brittle to bend anymore (planes don't slide well through dislocations). In a ceramic, flexure causes intrinsic pores and cracks to propagate until a large fracture forms. In a ferroelectric, ions move back and forth from their rest position under an applied field to store charge. In everything, atoms and ions diffuse over time leading to likely degradation of properties. I wouldn't really consider diffusion or ion polarization "movement", but in the case of a ferroelectric you are repeatedly straining the crystal in each charge/discharge cycle even if nothing is "moving".
In a metal (and other materials), there are both elastic strain: reversible stretching of bonds between atoms, and plastic strain: irreversible crystal planes inching and sliding over one another. (side note: metals are not as "strong" as ceramics in that a ceramic strains less under a given stress, but metals enter the energy absorbing plastic strain region while ceramics undergo brittle failure). If the movement is entirely elastic, then it's possible that diffusion is the only potential killer, or crack propagation; crack kills. I don't think a single walled perfect carbon nanotube could even strain plastically nor fail from crack propagation, but multi-walled tubes could strain plastically I imagine, and I don't think there are perfect (crack free) nanotubes.
A mechanical moving switch (which is the type of switch I imagined you were talking about) has problems of shear forces on the contacts wearing them down rapidly until they no longer contact. Or other forces deforming whatever is used to form the fulcrum. Nanotubes are held together by covalent bonds and (importantly) free electrons spread over the bonds like a benzene ring. Even long straight chain hydrocarbons don't spontaneously crack - and they bend and flex many more times a second than a carbon nanotube will in an electric field. The only problem then is the contact that it meets where it is probably held in place by Van-der-Waals forces. The nanotube will pull on the contact until the Van-der-Waals force is broken (it will break *way* before the covalent bonds in the nanotube) - but the forces binding some of the surface atoms of the contact could break first or at about the same time. There are very hard conducting surfaces that can be made and these will probably not fail for many years. I would not be suprised if they have or can make a device that is reliable enough for nearly any purpose, and certainly reliable enough for consumer and office electronics and short term (few years) space missions.
Yeah, although, looking at the flash intro, it says "Unlimited Lifetime". Which would suggest that it is pretty reliable, or at least that the life is not related to the number of times it switches as it is with flash.