3ω Method for thermal conductivity measurement of thin sheet materials

The 3ω method is widely employed for measuring the thermal conductivity of bulk, powder, liquid, and fibrous materials owing to its excellent versatility and accuracy. However, for sheet materials, the 3ω method usually requires depositing a metal electrode on the material, and sheet materials with rough surfaces, therefore, are difficult to meet the testing requirements of the 3ω method. In this study, a two-dimensional heat conduction model of the 3ω method suitable for thin sheet materials with/without rough surfaces was proposed, and it was used to measure the stainless-steel sheet and aluminum foil materials. The samples were suspended by four metal testing electrodes, and their thermal conductivity was measured and compared with standard values. The results indicate that this method can accurately measure the thermal conductivity of two-dimensional thin sheet conducting materials, thus extending the practical application scope of the 3ω method.