Carbon nanotubes (CNTs) are being studied for applications in high-strength/low-weight composites and other applications. Recent research on thermal dissipation materials for high-power electronic devices is generating a lot of interest in various industries. NASA has developed a method for cooling a device, such as an electronic device, that produces extreme heat that must be dissipated. CNTs have attracted much attention due to their extraordinary mechanical and unique electronic properties. Computer chips have been subjected to higher and higher thermal loads and it is challenging to find new ways to perform heat dissipation. As a result, heat dissipation demand for computer systems is increasing dramatically. CNTs, which are known to provide high thermal conductivity and to be small and flexible, are suitable for cooling these electronic devices. One critical problem is provision of a compliant, usable composite of CNTs with a material that meets other needs for heat dissipation.
Carbon nanotube materials are one of the most versatile materials with high thermal conductivity. CNT arrays are grown using chemical vapor deposition (plasma or thermal) on a suitable substrate, such as copper (Cu), with minimal interface resistance. The surface coverage will usually be less than 100 percent. The array is dipped into melted paraffin until the interstitial spaces between adjacent CNTs are filled with paraffin grains. In one embodiment, interstitial regions of CNTs, grown on a substrate, are filled with a first layer of Cu and with a second layer of a mixture of thermal grease and Cu, Indium, and/or silver particles. In a second embodiment, the interstitial regions are filled with a mixture of xylene (partly evaporated) and solidified paraffin, and then sliced to a desired thickness. Such a CNT-based composite would quickly and efficiently conduct thermal energy away from the device and hence provide cooling.