A thermo-optical plane source method to measure thermal conductivity

We demonstrate a Thermo-Optical Plane Source (TOPS) technique to measure the thermal conductivity of materials. This high-throughput method measures the thermal conductivity of materials with minimal sample preparation and limited restrictions on sample shape and geometry. Moreover, the technique is applied to solids, liquids, gels, and pastes with no change in implementation. The TOPS technique uses laser heating to induce a steady-state temperature rise in a material and infrared thermography to measure the corresponding temperature rise. Fourier's law is applied to directly measure thermal conductivity, rather than thermal diffusivity or effusivity, eliminating the need for prior knowledge of density and specific heat. We demonstrate the ability to measure thermal conductivities ranging from 0.03 to 60 Wm-1 K-1 at room temperature.