How To Cut a Nanotube? Lots Of Compression 38
An anonymous reader writes "A pipefitter knows how to make an exact cut on a metal rod. But it's far harder to imagine getting a precise cut on a carbon nanotube, with a diameter 1/50,000th the thickness of a human hair. In a paper published this month in the British journal Proceedings of the Royal Society A, researchers at Brown University and in Korea document for the first time how single-walled carbon nanotubes are cut, a finding that could lead to producing more precise, higher-quality nanotubes. Such manufacturing improvements likely would make the nanotubes more attractive for use in automotive, biomedicine, electronics, energy, optics and many other fields."
Re:Cancer? (Score:5, Interesting)
They have been show to behave in a manor similar to asbestos when inserted into mouse tissue http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2783215 [nih.gov]. However, when trying to determine the dangers of using a given material in a product there are two factors that need to be considered. One is how large of an expose is dangerous. Water will kill you if you drink enough of it. The second other is mechanisms of exposure. If you smashed the glass in your window and ate it would shred your stomach lining and probably kill you. Does this mean that we should ban the use of glass?
The reason asbestos was so bad is they put it in insulation, which when disturbed released a lot asbestos into the air. From there it could be inhaled. You can design a product using carbon nanotubes in such a way the the risk of exposure minimized. This would include steps such as embedding the carbon nanotubes in a polymer in a fashion such that significant quantities of carbon nanotubes will not be released into the air and coating the surface of the product with a material to will prevent significant quantiles from being absorbed though the skin while in contact.
There are two reasons that carbon nanotubes have not shown up in commercial products. The first is price. If I am recalling correctly carbon nanotubes cost about 100 dollars per gram. For comparison the price of gold in about 30 dollars per gram. The second is that actually carbon nanotube composites have so far had properties far worse than classic composites models would predict. Two reason for this are that carbon nanotubes are hard to evenly disperses within the filler material and the bonding between the filler material and the carbon nanotubes has been more problematic than it has with larger diameter fibers such as carbon fiber. That being said carbon nanotubes still have the potential to be a hugely useful material for many possible applications; however, there are still many basic research questions about producing and using carbon nanotubes that need to be resolved.