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Fun With Nanotechnology Advances
wieselwerkstatte sent us a link to a Nature article that talks about the possibilty for self-soldering molecular wires. In related news, demon-cw sent us a C't story about .2 buckyballs that they are using to create nanotubes. Use the fish for those who don't speak German.
Who modded this up?
Christ, people, this is totally off topic.
So he's in the nanotech industry (or so he says). What does he want, a cookie!?!
Well, since Voltage(V) = Current(I) * Resistance(R), then it really doesn't matter whether or not it's the current or voltage that causes the heat unless you have a zero resistance material. Now, since this is a self-soldering (supposedly) wire, then it seems to me that it must have some resistance, otherwise the entire length of wire would melt if enough heat is applied to one end of the wire.
Frankly, I don't want anything like this in my computer, or anything I own. I have enough problems with wires that melt (okay insulation too) when overheated already without having wires that can melt on their own.
Kierthos
Mr. Hu is not a ninja.
Smaller circuits generally generate less heat, but it really all depends on what the circuit is desgined for, how long it stays active, etc.
As for practical applications:
Umm, if you could reasonably control when the wire would melt, then you could use it to establish/re-establish electrical connections in limited-space areas without neccessarily having to crack open a case. Control the movement of the wire with micro-tools, and you're all set.
It might also be used to speed up mass production of chip-sets. Maybe. This is pretty much all guesswork on my part.
Potential failures:
What happens if it melts or re-melts at the wrong time? It seems to me that right now, this is the last thing in the world that you would want to use on anything you'd like to keep around. What if the wire melts at the wrong time or in the wrong way and establishes the wrong sort of connection? What if it re-melts later and fries something important?
Okay, now no corporation in their right mind is going to use this stuff in their current product lines. One, it's probably more expensive then using normal electrical solder (which I recall being pretty cheap). And two, with the potential failures that I listed (not to mention any other problems that could creep in), they'd be open to lawsuits real quick. And corporations hate lawsuits.
Just my $0.02 on this.
Kierthos
Mr. Hu is not a ninja.
So I was thinking "Of course he's read about the fish...".. given that you must have used it before and seen The Link. Oh, wait... The HyperLink on altavista's page... oops webpage which explains all about the fish .. damn .. the babelfish and its origins. it's a fish. It translates. the type of fish? Babel I guess. It's a babelfish. Calling it 'the fish' is not a bad thing. get over it.
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Video meliora proboque deteriora sequor - Ovidius
While I find all of this nano-buzz interesting, I think people generally attribute too much to it at the current stage in the game. It has enormous potential and it is definately flourishing but I don't think we're close enough to start throwing a big party yet.
UBU
I don't believe that is the point. When they say that the wires are self soldering, they don't mean that the wires melt and then fuse together.
What happens is the two gold "wires" are joined together by a long molecule whose ends preferentially bond to the gold. You can think of it like this, the "solder" is a string that has glue on both ends. You first coat material one with the strings and assume that only one end of the string will stick, the other end of the string now floats up in the air. You then bring the other material close by and the free ends of the string now stick to it. You have essentially bonded (or soldered) the two materials together with the strings. This is what is happening with thiols on gold.
Jeremy
Smaller is not possible
Michaela Simon 02.11.2000
A carbon tube with a diameter of 4*10^-10m (= 0.4nm)
The Nobel Price 1996 for Chhemistry was awarded for the discovery of a soccer ball - a very small one though. The "Buckyball" only consists of 60 carbon atoms. Its synthesis and detection awarded Robert F. Curl, Harold W. Kroto und Richard E. Smalley the price.
(Download)
The atoms of this molecule are placed exactly like the sextangular leather patches of a soccer ball. With this C60 is another modification of carbon among graphite and diamond. Until now quite a number of carbon spheres of different sizes have been found. The smallest one of this Fullerenes called class of carbon molecules - the C20 - was just recently described in the magazine Nature (2000, 407, S.60-63.).
(picture)
A few years ago there was quite an euphoria about C60 and relatives, and its applications in various areas of science was lively discussed (e.g. superconduction and HIV proteasis inhibition). Even if today anyone can order C60 in chemistry wholesale shops ($500 per gramm) there never was a real technological breakthrough.
The latter is hoped to come with carbon nanotubes - molecules formed like tubes that consist exclusively of carbon (like C60). These tubes were discovered 1991 by the Japanese researcher Sumio Iijima. Nanotube research started as offspring of Fullerene chemistry and is on its best way to surpass it.
(picture)
Carbon nanotubes consist of concentric graphite shells - between one and fifty of them which gives a diameter of 1-50nm. But nanotubes can be up to a millimetre in length - and it is this anisotropy that is of importance for applications. Fibers made of nanotubes are said to have an enormous tensile strength (100times stronger than steel with 1/16th of steel's weight). The interior of these tubes can be filled with various material (e.g. hydrogen) - even chemical reactions are possible within these miniature test-tubes.
Because of teir special electronic properties these tubes could become an important part of future nano technology.
(picture)
In today's issue of Nature two research groups from Hongkong and Japan report independently about the(ir) world smallest nanotube (Nature, 2000, 408, S. 50 und S. 51). It only has a radius of 0.2 nm (nanometers, 2*10^-10m). According to theory scientists this radius is the ultimate as smaller tubes won't be stable any more.
The extreme curvature of the carbon shells creates unusual physical properties: along the axis these tubes a metal-like conductivity is postulated. Further properties of this smallest of all nanotubes have to be researched, but be prepared for suprprise.
Nanotechnology is going to destroy the pathetic United States, as well as every other country in this world? Why, you ask? Because the technology has the potential to:
1) Make humans immortal (or pretty close to it)
2) Grant humans the use of 'unlimited resources'
3) The ability to learn things much quicker
Do you honestly believe that a military or politician(s) will be able to keep this technology to themselves? That is absolutely impossible, considering the people with the real brains aren't even in the military or the government, and if the government decided to keep the technology for itself, these 'people' would just create a non-commercial nanotechnology which they would release to everyone, in the name of rebellion against a government that never worked properly or efficiently in the first place.
The United States may be eager for Nanotech, but the truth is they are also horrified of it. Why? Here is the truth that the morons in our governent don't want you to know: NANOTECHNOLOGY WILL BRING THE ABSOLUTE DEATH OF DEMOCRACY AND CAPITALISM. Wow, it looks like they have every right to be afraid. No more government - no more money system! WHAT ARE WE GOING TO DO!?
That answer is simple - we are going to become Gods, and there is NO ONE alive or dead who can stop this from happening.
'Death to the pathetic United States, and death to Democracy and Capitalism!! Good riddance!'
That is not what they mean. When they say that the wires are self soldering and that when they ramp the voltage the conductivity drops, they don't mean that the wires melt and then fuse together and remelt and break apart.
What happens is the two gold "wires" are joined together by a long molecule whose ends preferentially bond to the gold. You can think of it like this, the "solder" is a string that has glue on both ends. You first coat material one with the strings and assume that only one end of the string will stick, the other end of the string now floats up in the air. You then bring the other material close by and the free ends of the string now stick to it. You have essentially bonded (or soldered) the two materials together with the strings. This is what is happening with thiols on gold.
Now the thiols only like to conduct one way (like a diode). When they reverse the polarity, the thiols stop conducting. The wires are still soldered together, it's just that they no longer conduct current between them.
Jeremy
How many covalent bonds does it take to get to the chewy center of a Buckyball?
C-C: 1
C=C: 2
CHOMP! Three!
Three.
The REAL jabber has the /. user id: 13196
The REAL jabber has the user id: 13196
What you do today will cost you a day of your life
we finally have the technology to make really easy to hide pea shooters.
The teachers arn't going to like this one bit.
The breaking strength of an object increases (roughly) as the square of the linear dimension. The mass increases with the cube. If you shake something (or drop it), the stress it experiences is proportional to the mass. Bigger things are generally more fragile than smaller things.
You can drop a small ant from a height of a meter, and the ant will walk away. If you drop an elephant from a meter, the elphant will break bones and end up dead.
Nanotech stuff is likely to be so tough that you couldn't even crush it without a diamond hammer, let alone break it by shaking it.
Also, one of the fun things you can do with (dream) nanotech is to build big things to atomic precision. A one-meter cube of monocrystalline diamond is not a fragile object.
There are many factors at play. One of which is the density of thiols on the surface. When you have enough thiols on the surface, they will arrange themselves in a 2-D lattice that is commensurate with the gold lattice (or something close to that). Once they are packed tight enough, they have to point up (actually they tend to lean, but that gets far to complicated and depends on the thiol length and lattice constant).
Another factor is the length of the thiols. If the thiols are short, then they won't want to bend over. If they are very long, they might bend a little. Also the bonding configuration between the atom on the end of the thiol and the gold surface might not allow for the thiol to lean very far.
This is a very active field in Chemistry/Physics/Material Science. There are numerous materials that you can form these self-assembled monolayers on (gold, silver, InP, GaAs, etc...) but gold is probably the most commonly studied surface.
We played with alkanethiols on GaAs for a few months (several years ago) in our lab, but I haven't really been keeping up on the literature.
For a lot more information, do a search for "self-assembled monolayers" on google (or your favorite search engine). This field of research is huge and very interesting.
Jeremy
You used the word "Geek" and "iMac" in the same sentence.
I think what you meant was "Oh, darling! A gold-accented dual 1.2 gHZ Thunderbird, with (Debian/NetBSD/let the holy war begin), gold-thiol technology, and diamond trim! Of course I'll marry you!"
--- Jump!! Fire!! Bullet time!! - Lego version of the Matrix
Once upon a time, not very long ago, you had to speak German to become anything in any technological or scientific field, because most literature, or at least the most recent literature, was in German. Only very recently has this begun to change. Especially in computer science and electrical engineering, most literature is now in English, but literature regarding chemical engineering, physics and biology is still mostly German.
Instead of whining that you have to use Babelfish, whining that everybody should learn English - why don't YOU learn German? Personally, I speak Dutch, English and German, and a little bit of French - and I wish I hadn't dropped that in higschool...
)O(
Never underestimate the power of stupidity
Never underestimate the power of stupidity
To err is human, to moo bovine
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