Probing technique for localized thermal conductivity measurement

A low-cost and non-destructive measurement technique based on the combination of a temperature sensor and a heater integrated in a very sharp tip is proposed for the determination of thermal conductivity of planar materials. The thermal sensor is fabricated by means of microtechnology technique. Associated to the system, an analytical thermal model is developed to express the measured Seebeck voltage as a function of the material thermal resistance. A numerical analysis based on COMSOL Multiphysics. is then developed to extract the thermal conductivity from the thermal resistance. To validate the approach proposed, experiments on planar dielectric materials and metals are conducted. Precision around 0.1 W m(-1) K-1 for thermal conductivities lower than 2 W m(-1) K-1 is obtained.