Characterizing thermal diffusivity of synthetic spider silk using improved transient electrothermal technique

This paper presents an improved method for measurement of the thermal diffusivity of thin fibers, motivated by the measurement of thermal diffusivity of a synthetically produced spider silk. This synthetic spider silk is being developed for lightweight thermal management applications. The transient/generalized electrothermal technique (TET) has been previously developed to characterize thermal properties, such as thermal conductivity and thermal diffusivity, of thin fibers, but can have significant errors when applied to nanoscale samples. A new, full model was developed to reduce these bias errors by including far-field radiation heat losses, convection heat losses, and non-constant heating effects. The bias errors associated with the original, or reduced, TET model are related to applied currents during experimental measurements of a thin platinum wire. Because the full model requires information about the thermal conductivity of the material of interest, the reduced model should be used as an initial approximation for the thermal conductivity of the fiber to be used in the full model to get a more accurate thermal diffusivity result. This full model can improve characterization of microwires' thermal properties and allows for variations in the process treatments to be more accurately characterized.