Tuesday 19 February 2013

Dense, Dense, Dense Nanotubes for Better Electronics

To meet these requirements, the researchers used a fabrication technique called the Langmuir-Schaefer method, which involves dispersing pre-enriched semiconducting nanotubes on a water surface. The floating nanotubes spread out to cover the whole surface as a result of the surface tension. Applying a compressive force assembles the nanotubes into well-ordered arrays, and the compression is stopped when the nanotube film becomes incompressible, which indicates that nanotube arrays have covered the entire surface. The resulting nanotube arrays have a 99% semiconducting purity and are aligned within 17° of one another.

Read more at: http://phys.org/news/2013-02-densest-array-carbon-nanotubes-paves.html#jCp
To meet these requirements, the researchers used a fabrication technique called the Langmuir-Schaefer method, which involves dispersing pre-enriched semiconducting nanotubes on a water surface. The floating nanotubes spread out to cover the whole surface as a result of the surface tension. Applying a compressive force assembles the nanotubes into well-ordered arrays, and the compression is stopped when the nanotube film becomes incompressible, which indicates that nanotube arrays have covered the entire surface. The resulting nanotube arrays have a 99% semiconducting purity and are aligned within 17° of one another.

Read more at: http://phys.org/news/2013-02-densest-array-carbon-nanotubes-paves.html#jCp


See the compression from the top to the bottom frame.Kibron MTX-LB has arriers that can do this simply and accurately.   



Researchers are doing really cool stuff at IBM (especially at the Thomas J. Watson Research Center).  Besides their feats on Jeopardy they are building dense array nanotubes.  They want to make  carbon nanotubes that are purely semiconducting, well-aligned and cover the entire substrate.  You would have thought that would have been done already.  Right?  Not so...

The Langmuir Schaefer technique is employed here.  A Langmuir-Schaefer film is when one or more monolayers of material (in this case nanotubes) is deposited  from a liquid surface onto a solid substrate. It can be done by dipping the substrate horizontally through a floating monolayer at a constant molecular density) or by placing the substrate in contact with the monolayer.  Here they used method involves dispersing pre-enriched semiconducting nanotubes on a water surface.  Due to the high surface tension of water the nanotubes float and spread over the surface.  Using something like the Kibron MTX-LB you can compress these nanotubes into well-ordered arrays.  This is similar to compressing lipid films.  When the nanotube film becomes incompressible this is an indication that the nanotube arrays are maximized.

So what has improved?  This method allows an increased density of 10 x more.  This array covers 500 tubes per micrometer on 100% of the surface whereas the previous array only covered 50 tubes per micrometer on 10% of the surface.  Not only that but these tubes can be double packed!

With the increased density better lower cost electronics can be built from the nanotubes.  For example that new thin film mobile device that is flexible, economically disposable and possibly optically transparent can be built with ease.  This kind of technology may not go into the Apple iWatch but in the future we might be able to see them in other wearable electronic devices.  These wearable devices would be substantially better than previous thin-film materials because the more dense equals faster operating speed and lower output resistance. 


See original article here: http://phys.org/news/2013-02-densest-array-carbon-nanotubes-paves.html