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.'"

That's a neat graphic in the article...

[Adult film producer]

what the hell does it mean though ?

http://physicsweb.org/objects/news/9/8/2/050802.jp g [physicsweb.org]

Any More?

[irokie]

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...

What it means

[standards]

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.

Weird

[jurt1235]

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.

One of a dozen daily....

[Solipson]

... 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.

Carbon is a semiconductor

[lcsjk]

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!)

What is new in here ?

[karvind]

I am sure researchers working on CNT (carbon nanotubes) will back me up on this. But what is new in here ?

(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.