Fig. 5: Helical Janus hydrogel fiber conductors of extremely large deformations and low temperatures tolerance.

a Photograph of various helical Janus fibers. b Elongation and spring index versus the spring diameter. c Cycled loading of the fiber conductors to large strains. The inset shows the helical fiber consisting of intimately contacted coils of ~2.9 mm diameter. d Resistance change of the conductors as a function of tensile strain. e Dynamic resistance of the conductor (~2.9 mm diameter) under a 1000% strain cycle. f Ultrastretchable and low temperatures tolerable LED lighting.