Dense, vertically aligned multiwalled carbon nanotube arrays as thermal interface materials

Carbon nanotube (CNT) arrays are being considered as thermal interface materials (TIMs). Using a phase sensitive transient thermo-reflectance technique, we measure the thermal conductance of the two interfaces on each side of a vertically aligned CNT array as well as the CNT array itself. We show that the physically bonded interface by van der Waals adhesion has a conductance similar to 10(5) W/m(2) K and is the dominant resistance. We also demonstrate that by bonding the free-end CNT tips to a target surface with the help of a thin layer of indium weld, the conductance can be increased to similar to 10(6) W/m(2) K making it attractive as a TIM.