Nanotubes is a hot alternative for a future replacement of the silicon-based transistor. A number of varieties of how nanotubes can be used as a transistor has been presented (1, 2, 3), but nanotubes can be used for so much more. According to scientists at Rensselaer Polytechnic Institute, assisted by people at the University of Oulu in Finland, nanotubes could be used for cooling circuits in the form of microfins. Through a fin structure with multi-walled nanotubes and then mounting them on a chip, they’ve been able to show that nanotubes removes heat just as well as copper. The difference is that nanotubes are more flexible, resilient and ten times lighter.
“As devices continue to decrease in dimension, there is a growing need for miniature on-chip thermal management applications,/…/”When reduced to sub-millimeter sizes, the integrity of materials typically used for cooling structures breaks down. Silicon becomes very brittle and easily shatters, while metallic structures become bendable and weak.” – Robert Vajtai, researcher with Rensselaer Nanotechnology Center.
The advantages of nanotubes are more though. While metals have a tendency to become very brittle when made very thin, nanotubes remains strong, light and are also cheap to manufacture. They’ve developed a method that makes it possible to coves a circuit with 1.2 millimeter long nanotubes, which was enough to keep the test circuit cool.
The results published by the group of scientists have revealed an improved heat dissipation of 11% at regular airflow, while the figure can be improved to 19% when using forced nitrogen. The idea is not to cool our monster PC processors but small chips found inside our mobile devices and other minimal devices.
“These numbers are consistent with the heat dissipated by the best thermal conductors, and demonstrate the possibility of a lightweight, solid-state add-on structure for an on-chip thermal management scheme which works without involving heavy metal block and fan or fluid-flow procedures for heat removal which can greatly increase the weight of electronic devices,”
The article was published in Applied Physics Letters, march 19 2007 and is available online here.
