The effect of a CNT interface on the thermal resistance of contacting surfaces

Experimental and theoretical analyses were used to study the effect of thermal contact resistance in two materials, aluminum and graphite. Experimental investigation included the use of a modern laser flash device to measure the effective thermal conductivity of each material for three different cases: in direct contact, with a graphite coating and with a thin sheet of carbon nanotube (CNT) thermal interface material (TIM). For both materials total thermal resistance values were determined corresponding to different cases for same contact pressure. Results showed that the CNT TIM produced the minimum thermal contact resistance. A theoretical study was carried out to compare the experimental results with thermal resistance models from the literature. Based on the surface roughness of the materials tested, two models were used. Both models showed reasonable agreement with the experimental results with an error of less than 6.5%. The results demonstrate the effectiveness of CNT materials in improving the thermal conductance of contacting surfaces.