Probing the mysteries of spider silk's uncharacteristically high thermal diffusivity

Spider silks exhibit excellent strength, stiffness, and toughness simultaneously, a feat unachievable in most synthetic, structural materials. It has recently been reported that the thermal conductivity of dragline silk is comparable to copper, which is uncharacteristically high for a biomaterial. In order to develop a fundamental understanding of the high thermal properties of spider silk, further research must be made to explore how the structure and organization of spider silk proteins affects heat transfer characteristics. Synthetically produced silks created from spider silk proteins obtained from transgenic sources can be used to determine these protein structure effects by varying protein content and process treatments. This initial study determined the thermal properties of synthetic spider silk created from transgenic goat's milk proteins using the transient electrothermal method (TET). Results show that the thermal properties of the synthetic silk are lower than the natural spider silk but vary based on the process treatment, and that the annealing of the gold film coated on the fiber has no effect on the measured thermal properties. These results provide a framework for further research on the protein content effect and its role in thermal properties.