Nanoscale conformable coatings for enhanced thermal conduction of carbon nanotube films

Vertically aligned carbon nanotube (CNT) arrays can provide the required combination of high thermal conductivity and mechanical compliance for thermal interface applications. Much work in the last 15 years has focused on improving the quality and intrinsic thermal conductivity of the nanotube arrays. Currently the thermal interface resistance between nanotube arrays and surrounding materials limits the overall thermal performance. To reduce this interface resistance, we propose coating the nanotube film with a continuous layer of metal. In this work, we electroplate 1 to 20 μm-thick continuous copper films directly on the carbon nanotube array. We measure the thermal conductivity of CNT arrays after electroplating using cross-sectional infrared microscopy. For low volume fraction, vertically-aligned carbon nanotubes arrays with copper electroplating (0.5 vol. %), the film thermal conductivity is nearly 3 W/m/K. These results demonstrate the feasibility of the electroplating method to coat CNT films.