Slashdot Mirror
Circuits Better with Purer Nanotubes
Mark_Uplanguage writes "PhysicsWeb has an article on improving techniques for the use of carbon nanotubes in electronic circuits. From the article, 'Physicists in the US have developed a new method for making electronic circuits with carbon nanotubes. The technique involves dipping semiconductor chips into a purified solution of nanotubes, rather than the conventional method of growing the nanotubes directly onto the chips. The resulting devices are much better than those produced by other approaches.'"
what the hell does it mean though ?
p g
http://physicsweb.org/objects/news/9/8/2/050802.j
That there are quantum mechanical problems with having the tubes alligned and getting a good signal through them.
does any one have a link to an article that's more than just a blurb? What are the applications? How long before we can built Logic out of these chips? According to TFA, all they've managed to create so far is an FET...
and if you see me strut, remind me of what left this outlaw torn...
And if the nanotubes were in solution, they wouldn't be nanotubes any more.
So, are you a dipper or do you cover them with sauce first? Science have proved that the dippers are using a superior technique...
chips: n. [British] Fried potatoes cut into thick rectangular strips. see fries [American].
Conversion Rate Optimisation French / English consultant
OK, they used the wrong word. They should have said "a suspension containing nanotubes".
No folly is more costly than the folly of intolerant idealism. - Winston Churchill
Just a word of warning for those not familiar with this advance - there are still a lot of issues to be worked out to being this technology into the field.
My group estimates that it will be 10 or more years before we see this technology impacting consumers around the world.
We all want much more powerful CPUs in a smaller package disapating little heat. But so far built only a few transistors using said technology - far from the density and complexity of a next generation CPU. The reliability of the process needs to be made very very high, orders of magnitude high, in order to make a next generation CPU using this technology... and those techniques are far, far away from being available today at any high volume chip fab facility.
Don't get me wrong - its an important scientific advance, but the manufacturing process still needs a lot of new science to make it happen in a way we'd like to see it.
So you have nanotechnology in use, but for a production application you will use the technology by just dipping the, in this case computerchips, into the liquid, instead of carefully placing everything on the chip how it should be.
Suppose this works because there are hooks on the chip on which the nanotubes get stuck. How do you know that two opposing hooks attach to the correct same nanotube, and not to the wrong nanotube, or to two nanotubes with no connection at the other end at all.
I think this works nice in a lab where you only measure certain performance parameters from the use of nanotubes, but that a real chip will not work with this method.
Pure nanotubes work better: That is to be expected based on the properties of a nanotube (guessing here). I think an assembling method to place the nanotubes so you are sure they are at the correct place, is a better direction for this research than a huge chip dipping facility. If they want to do the last they will have to get a license from Pringles anyway, they have the best dipping shape for chips.
My wife's sketchblog Blob[p]: Gastrono-me
... press releases about breakthroughs in nanotech especially in the carbon nanotube/semiconductor field. One should know that the US, EU, Korea and Japan throw an unprecendented amount of money into research in this field right now. And as the yanks have set the success metrics, it means all the researchers have to do is churn out press releases and file patents :-)
So, don't hold your breath re dipping, licking and roasting electronic circuits with CNT's.
These are not "purer nanotubes". They are more nanotubes and less other junk. Nanotubes grown on a surface will tend to also create other carbon molecules like ash, diamond crystalites, and even buckyballs. The purified stuff is simple this same mix of materials, but filtered to only have the tubes. They're still the same quality of tubes, just not dilluted w/ other crud.
"I must not fear. Fear is the mind killer." -Bene Gesserit Litany Against Fear
Right. Just like the US military / industrial complex had been using silicon chips for 30 years before the Altair, or vacuum tube computers 30 years before the first commercial computer.
FYI, the timeline:
1943: Colossus
1946: ENIAC
1958: first IC
1971: first CPU
1975: Altair
Not so. You can have macromolecules is solution without destroying them. For example, fullerene dissolves in toluene. The molecules don't break up, but they acquire a coating of toluene molecules on the surface which means that they act as part of the liquid instead of a solid. When the toluene is evaporated, the buckys are fine.
In fact, there's a good chance these nanotubes are bucky-derived so they might even be in a toluene solution in TFA (which I haven't read cos I don't care about chip manufacture, I was just reading for the '+5 Funny's).
J.
You're only jealous cos the little penguins are talking to me.
I disagree.
What about Packard Bell computers?
They were made with poor, used, and substandard parts with bad drivers, and yet the computers were still...
Maybe I agree after all.
I think that the demise of Packard Bell in North America is totally justified.
Exam 4/C again. Maybe I'll do better this time.
Electronics have now evolved through the semiconductor portion of the periodic table of the elements. The early crystal radios used element 82,lead sulfide (galena from wikipedia), then during the early 1900, the so-called foxhole radio used razor blades and pins made from element 50,tin, to make a crystal. Early transistors used element 32,germanium, and integrated circuits moved onto element 14, silicon. The nanotube technology is now moving us to the last of the series which is element 6,carbon. This progression from lead to carbon is also a progression from larger molecules to smaller molecules and fewer elecrons. It took about 50 years to get to silicon and another 50 years to get to carbon. Where will we be in another 50 years?? (Don't be funny and say dead!)
(a) No, these transistors are no better. If you check the nature article, the contacts to the transistors are still lousy (technically, they are still schottky and not ohmic). And contact resistance is too high.
(b) No, they don't really get the nanotubes where they want as claimed in the article. The alignment using this technique is still worse (will require substantial effort to make it better).
(c) One of the bigger drawbacks which was conveniently ignored was the fact that they still cannnot control the number of tubes between the two contacts. So it can be 1 or 2 or 5 and so your current or other properties will vary that much. This technique doesn't make this problem any better.
(d) Last but not the least, no comment about the role of oxygen. All other researchers struggle due to hysteresis behavior, these devices look similar to them.
Man the military-industrial complex is SO 1960's, now it's the PLM, Political, Legal, Media, complex that we worry about. All hail the Senator from Disney, and Mickey Mouse's perpetual copyright protection!
Apocalypse Cancelled, Sorry, No Ticket Refunds
Technically, that's not the whole truth. Carbon in graphite form
is a semimetal at room temperature (has nearly zero
temperature coefficient of conductivity); at lower temperature
it is a semiconductor, at higher temperature it is a conductor.
The high temperature behavior is similar to a semiconductor
'going intrinsic' (Germanium does this at an inconveniently
low temperature, Silicon goes to several hundred Celsius
first).
No one used graphite semiconductors much because the
lattice is VERY strong in one dimension and weak in another;
diffusion of impurities is quixotic. Also, fracture can occur
easily. Nanotubes are different in interesting ways from
graphite in these regards.
It's common (or used to be) to use the abrupt resistance rise
of a carbon resistor to implement dipstick functions for
liquid nitrogen containers. It's also possible to dope
graphite for very high electrical conductivity (I've heard it
can exceed that of copper). Both these are semiconductor
electronic applications, though crude ones.