High-Conductance Thermal Interfaces Based on Carbon Nanotubes

The new devices and missions to achieve the aims of the NASA's Science Mission Directorate (SMD) are creating increasingly demanding thermal environments and applications. A key element that drives the design of thermal management systems in these demanding applications is the thermal interface material (TIM) between mating surfaces. Our innovation is a novel, vacuum-compatible, durable, heat-conduction interface that employs carbon nanotube (CNT) arrays directly anchored on the mating metal surfaces via microwave plasma-enhanced, chemical vapor deposition (PECVD). By directly anchoring the CNTs to the metal surface, the joint conductance is substantially increased over current TIMs due to the elimination of thermal contact resistance at the metal surface-TIM interface. During the Phase I project, we demonstrated thermal resistance values of approximately 35 mm2 K/W at a contact pressure of 0.7 MPa in testing at Creare for a direct-deposited, CNT-based, thermal interface on copper substrates. Using this approach, our team partner has demonstrated thermal resistance values as low as 8 mm2 K/W, demonstrating the remarkable potential of this innovation. The use of our innovative CNT-based TIMs will enable increased reliability, decreased size, and increased performance of spaceborne thermal management systems for the SMD.