Indium Assisted Multiwalled Carbon Nanotube Array Thermal Interface Materials

The state-of-the-art thermal interface materials (TIMs) for electronic cooling is briefly reviewed with an emphasis on the emerging trend of employing carbon nanotubes (CNTs) for enhanced thermal conduction across interfaces. Previous studies on CNT TIMs, however, indicated that despite the high thermal conductivities of CNTs themselves, heat conduction is limited by the direct contact interface between CNTs and the target surface. This has greatly limited the practical application of CNT TIMs. In this study, we thermally welded a thin indium layer between the CNT surface and the target surface, and observed an order of magnitude increase in thermal conductance ~10⁶ W/m² middot K across the interface compared with direct contact interface. With vacuum and cryogenic temperature compatibility, indium assisted CNT TIMs may find their future applications in areas from electronic chip cooling, cryogenic pumps, to thermal management in spacecrafts