New Secrets of Spider Silk: Exceptionally High Thermal Conductivity and Its Abnormal Change under Stretching

Two new significant discoveries are reported: i) the dragline silk of N. clavipes spider has an exceptionally high thermal conductivity: up to 416 W/m·K that beats most materials; ii) contrary to normal materials, its thermal conductivity increases with strain (19% increase under ∼20% strain). These new findings will revolutionize the design of polymer fibers to increase their thermal conductivity by orders of magnitude.