Design and Application of a Freestanding Sensor Based on 3ω Technique for Thermal-Conductivity Measurement of Solids, Liquids, and Nanopowders

A practical and reusable freestanding sensor based on the 3 omega technique is fabricated by encapsulating a nano-thick nickel detector between two pieces of Kapton film. Because of the protection of the Kapton layer, the mechanical strength and applicability of the sensor are greatly improved compared with the traditional 3 omega sensor. Furthermore, the nondestructive thermal-conductivity characterization for solids, liquids, and nanopowder specimens based on the 3 omega technique is first realized. However, the introduction of the additional protective film also induces an undesirable decrease in accuracy for the thermal-conductivity measurement. This article discusses the underlying reason for this decreased accuracy and accordingly proposes an error correction scheme for accurate determination of the thermal conductivity.