Fig. 2.

Shape-induced functionalization. Quasi-static force measurements on spider capture threads combined with microscopic observations reveal that the core filament coils into the droplets ($\sim$ 250–300-μm wide) along a force plateau $T\sim T_{\text{P}}$ (liquid-like response). For larger forces, $T>T_{\text{P}}$, the fiber straightens and a solid-like behavior is recovered. The particular shape of this force–extension curve can be attributed to a shape-induced functionalization of the fiber by the glue droplets. See also Movies S2 and S3.