A steady-state method apparatus for measuring the thermal conductivity of flexible electronic materials under stretching

Abstract

The rapid development of flexible electronic devices has created an increasing demand for soft materials with superior heat dissipation properties. However, accurately measuring the thermal conductivity of flexible materials, particularly under dynamic conditions such as tensile strain, remains a significant challenge. In this study, we present a steady-state thermal conductivity measurement apparatus designed to operate under tensile loading conditions. We detail the system’s design operational procedures, data correction methods, and performance benchmarks. The apparatus was validated using standard reference materials, including quartz, stainless steel, and copper, producing thermal conductivity values of 1.57 ± 0.04 W m⁻¹ K⁻¹, 16.46 ± 0.39 W m⁻¹ K⁻¹, and 384 ± 19.62W m⁻¹ K⁻¹ (95 % confidence), all deviating from the reference values by less than 8 %. Additionally, we investigated the strain-dependent thermal conductivity of a liquid metal/Polydimethylsiloxane composite. The results demonstrate the effectiveness and reliability of our method, establishing a solid foundation for the thermal conductivity measurement of flexible materials in electronic applications.