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I just saw an article indicating researchers have found a way to manufacture carbon nanotube bundles in lengths of hundreds of meters (see link). This Idea intends to expand upon a point mentioned in the article, about how power transmission lines could be made using nanotube bundles. However, more
work is needed before nanotube bundles can be made both long enough and thick enough to carry the kind of electrical load typically sent through long-distance power-transmission lines.
On the other hand, if they can be made wide enough to carry something like 20 amperes of current, then these bundles could RIGHT NOW be a suitable replacement for the copper wiring in households and other buildings ("hundreds of meters" is plenty long enough!).
All that nanotube wiring needs is a suitable layer of insulation, and appropriate means of connecting the ends to common wiring devices like light switches, circuit breakers, electrical outlets, etc. It's already plenty flexible, being similar in composition to sewing threads. So, it could even be used in other wires like extension cords and power cords for lamps, microwave ovens, vacuum cleaners, refrigerators, etc.
Just in time, too! Carbon is a common element and all the world's copper mines are running out (link). Which is another reason to post this Idea --using nanotube wire to replace power transmission lines means using them to replace aluminum. We are not running out of aluminum anywhere near as quickly as we are running out of copper!
Long Nanotubes
http://www.technolo...w.com/energy/23921/
As mentioned in the main text [Vernon, Nov 12 2009, last modified Nov 24 2009]
Running out!
http://www.good.is/...als-for-everything/
As mentioned in the main text [Vernon, Nov 12 2009]
New news article
http://news.rice.ed...king-performance-2/
Now easier to make than before.... [Vernon, Jan 15 2013]
[link]
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While I like the idea of using low-resitance carbon tubes to replace copper wire, once you start using nanotubes in the 100's of meters, you're not using nano-anythings since nano refers to billionths of something. |
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Well, these long fibers are made of billions/trillions of nanosized tubes, the way a thick woolen thread is made from many individual hairs from a sheep's sheared "coat". I suppose it is a matter of perspective. After all, we say a wire is "copper" without bothering to mention the size of the atoms making it up, so calling a wire a "nanotube wire" does not necessarily have to mean the wire has the width of a single nanotube. |
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I must admit I was amazed by the first line of the article: |
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"A new method for assembling carbon nanotubes has been used to create fibers hundreds of meters long." |
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This is several orders of magnitude longer than the previous record (which was about 4cm). |
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The advantage of carbon nanotubes over copper is the maximum current density rather than conductivity. This makes it a good material for high voltage electricity lines but seems a bit of overkill for extension cords. Of course, if nanotubes become cheaper than copper, it'll become a no-brainer to use them everywhere where copper is currently being used. |
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Also, electricity transmission seems of a bit of a boring application of such long nanotubes. Applications such as space elevators seems much more interesting to me. |
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I suppose one consideration would be flexibility... To whit, how flexible is an individual nanotube? Similar to how individual glass fibres can be flexible because of their very small diameter (ie fibre diamerer:bend diameter ratio). |
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You'd have to be careful how you bundled the nanotubes together to ensure the bundling method doesn't resist transverse stresses (bundle loosely so the fibres can slip past each other and thus bend as a group). Binding with an epoxy or using some kind of cross-chain polymerisation would produce an incredibly rigid rod, not a wire. |
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One thing I've just thought of - I've seen people (read: idiots) tie things up with extension cords, and often when spanning an electrical cord over a long distance you have to tie it to a support cable. With the carbon nanotube wires having a tensile strength in the gigapascal range, it might lead to all sorts of interesting applications. |
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//an incredibly rigid rod// |
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Yes yes, snicker away children. |
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Carbon nanotubes (and nano refers to diameter, not
length, just like a 2" pipe can be yards long) conduct very
well along their length, not across. |
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The article refers to nanotube yarn, not single fibers. That
means a material made up of hundreds of thousands of
shorter fibers that do not join end to end. As a result
these will be poor conductors at best. |
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The article mentions metallic nanotubes for transmission
lines, which are good uniform conductors, but they are
structurally very different from carbon tubes, and don't
have the impressive structural properties. (still stronger,
pound for pound, than simple metal though) |
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You're right MechE, I didn't read the article very carefully, it is nanotube yarn not a single nanotube. |
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As long as a single dimension of the morphology is in the nanoscale range, then it's nano. Of course, all things have some sort of nanostructure, but it's the controlled structures with which we are concerned. I'm sure the current cost is far too high for revamping an already adequate infrastructure. Maybe in twenty years. |
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All the tech in the world to make something I can make in my chimney for free. Metaphoricaly of course as i don't have a chimney. |
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