Photoacoustic Technique for Thermal Conductivity and Thermal Interface Measurements

The photoacoustic (PA) technique is one of many techniques for characterizing thermal conductivity of materials, including thermal interface conductance or resistance. Compared with other techniques, the PA method is relatively simple, yet is able to provide accurate thermal conductivity data over a wide range of materials and properties. In the last decade, the PA method has been developed and employed for measuring thermal properties of many materials. In this chapter, we will discuss the theory of the PA method for thermal conductivity/thermal interface resistance measurement. We will also describe experimental implementation of the PA method. Finally, we will discuss a recent application of using the PA method for characterizing thermal interface resistance of carbon nanotube–based thermal interface materials.