Apparatus and methods are provided for efficiently and non-destructively determining the thermal properties of materials having arbitrary surface textures. Two regions of a sample are each contacted by respective pairs of probes, where each pair includes a first probe made of a first material and a second probe made of a second material. A voltage sensor is arranged between the two probes of each pair, and between the probes of the same material from each pair. Nodes connect the voltage sensors to the probes. A temperature gradient is established between the two regions, while the nodes are maintained at a constant temperature. The Seebeck coefficient of the material and the temperatures of the regions can be determined from the voltages measured by the voltage sensors.