Nanocarpets Decorating the Walls of Microchannels

Without the appropriate cooling, the operating temperature of electronic devices and micro systems could reach values where the components lose their physical integrity, and the proper functioning would cease. In response to this demand, many techniques have been studied and developed such as laser drilled cavities, heat sinks, micro fins, etc. but have still not been able to reach an adequate cooling performance necessary for the components to operate properly. Because of the large heat transfer surface area to volume ratio, microchannels cooled with gas or liquid coolant have been shown to be strong prospects. By lining the walls for the microchannel with nanocarpets — fins, pins, etc. that varies the roughness of the surface — it can alter the effect of the microchannel performance. Carbon nanotubes have extremely high thermal conductivities and they also can be made to have an additional increase in the wall heat transfer surface area. The use of approximated Boltzmann equations, Molecular Dynamics, and Computational Fluid Dynamics to model the heat flow in nanostructured surface microchannels, and also the nanotstructure-fluid interface will be reviewed. The explanation of important interactions, heat transport phenomena, the numerical experimentations related to effect of nanotube length, the nanotube type, the spacing of the nanotubes, and their staggered pattern, and their other physical and material properties in relation to the fluid flow properties within the microchannels will be discussed.