Measurement of Thermal Conductivity and Thermal Diffusivity of Solid Materials Using a Novel Stamp Sensor: A Feasibility Study with Numerical Analysis

Contact-probe methods have been developed to measure thermal transport properties of solid materials. Although they have an advantage of being used for non-destructive in-situ measurement, it has a substantial problem that the measured results are influenced by thermal contact between the probe and the specimen. To overcome this problem, we proposed a new technique using a gel to eliminate the contact resistance. A unique feature of the method is that a thin film heater is fabricated on a substrate at the bottom of a shallow cavity, which provides a gel layer of the thickness that is almost the same as the cavity depth. When we use this sensor, we press it against a surface of a specimen with a gel in between. We named it "stamp sensor" from its supposed use and appearance. The thermal conductivity and the thermal diffusivity of a specimen and the thickness of the gel layer are determined simultaneously by comparing the measured temperature rise of the sensor with that obtained by numerical analysis. The objective of the present paper is to demonstrate the feasibility of the method by virtual experiments. The process to determine the thermal conductivity and the thermal diffusivity was examined using simulated experimental data that have been generated from the temperature rise of the sensor obtained by numerical analyses with given artificial scattering. Effects of the scattering of the data, the heating power and the heating time on the measurement error were also discussed.