Prediction of the contact thermal resistance of vertical carbon nanotube arrays

The vertical carbon nanotube arrays (VACNT), as a result of its flexibility and axial high thermal conductivity, exert a huge potential and play an increasingly important role in thermal interface materials. This paper proposed a model which can predict the contact thermal resistance of VACNT. The contact thermal resistance of VACNT under different pressures is calculated and compared with the experimental data. Also, the effect of variations in the surface roughness and VACNT parameters on the contact thermal resistance is investigated. Results show that the theoretical results are in good agreement with the experimental data. The contact thermal resistance is composed of interfacial thermal resistance, constriction thermal resistance, and VACNT resistance. Among which the interfacial thermal resistance is the major thermal resistance. The variations in VACNT length and diameter can change the bending degree of VACNT under the same pressure, which presents important implications on contact thermal resistance and can be used to optimize the contact thermal resistance of VACNT. The surface roughness exerts little effect on contact thermal resistance.