Core–Sheath\nHeterogenous Interlocked Stretchable\nConductive Fiber Induced by Adhesive MXene Modulated Interfacial Soldering

Whereas high electrical conductivity and mechanical stretchability\nare both essentially required for flexible electronics, simultaneously\nachieving them remains a great challenge due to the “trade-off”\neffect. Herein, an ultrastretchable conductor with core–sheath\nheterogeneous interlocked structure was developed, induced by interfacial\nsoldering silver nanowires (AgNWs) which gradually evolved into elastic\nconductive fiber. Adhesive polydopamine-functionalized MXene (PDM)\nwas proposed as an interfacial solder to assemble AgNWs along fibers\nwhile induced strong cold-welding effect soldered them into superelastic\ninterconnected network. <i>In situ</i> coaxial heterogeneous\ninterlocking between core AgNWs and sheath PDM network gradually formed\nduring the interfacial soldering process, which enables elastic conductor\nsimultaneously owning large mechanical stretchability and high electrical\nconductivity. Stretchable conductive fiber with core–sheath\nheterogeneous interlocking structure not only exhibits excellent electrical\nconductivity (1.13 × 10<sup>5</sup> S/m) but also could maintain\nstability (Δ<i>R</i>/<i>R</i><sub>0</sub> < 0.19) even under large mechanical deformations (300%). Ultrastretchable\nfibrous conductor with core–sheath heterogeneous interlocked\nmicrostructure induced by adhesive PDM interfacial soldering holds\ngreat promise in soft electronics.