Enhanced thermal contact conductance using carbon nanotube arrays

Novel heat-conduction interfaces that employ carbon nanotube (CNT) arrays have been fabricated and studied experimentally. A reference calorimeter testing rig in a high vacuum environment with infrared temperature measurement has been established. Arrays of mat-type carbon nanotube layers have been grown directly on silicon substrates with microwave plasma-enhanced chemical vapor deposition. Iron and nickel are used as carbon nanotube catalysts. The thermal contact resistance of carbon nanotubes with a copper interface shows promising results with a minimum resistance of 23mm-K/W at a pressure of 0.445MPa. Carbon nanotube arrays grown under different synthesis parameters exhibit different pressure-contact conductance characteristics. CNT-copper interface thermal contact conductance could be improved by optimization of carbon nanotube array parameters. Combinations of thermal gels and phase change materials with CNT array composites are proposed for further thermal contact conductance reduction.