Using Nanotubes to Cool Processors
It can be very frustrating when you have a problem and a solution, but no effective way to marry the two. Such has been the case with microprocessors and carbon nanotubes, with heat becoming more a problem for the circuitry and nanotubes having exceptional thermal conductivity. After being approached by Intel, researchers at Berkeley Lab have successfully found a way to use nanotubes to cool the electronics.
What has been preventing carbon nanotubes from cooling electronics before is their chemical stability. Atoms and molecules will only form bonds when the resulting bonds would be more stable than the present ones, but the nanotubes are so stable, they do not bond to much. To get around this the researchers first grew vertically aligned nanotubes and created thin films of aluminum or gold on glass microscope cover slips. After functionalizing the films, they were allowed to bond with the nanotubes. The bonds were actually strong enough to pull the nanotubes off of the substrate they were grown on.
One way to compare the thermal resistance an interface adds to a system is to consider how much extra length it effectively adds. Typically thermal interface resistance adds around 40 micrometers to each side of a carbon nanotube, but this new technique dropped it to around seven micrometers, on each side. A significant improvement and by improving the density of nanotube/metal contacts, it should be possible to make the system even more effective at removing heat.
Source: Berkeley Lab