3D Knitted Fabric Composite Architecture for Ultra‐Stretchable Electrical Conductors with Superior Conductive Stability During Large Deformations

This work proposes an innovative design strategy for ultra‐stretchable conductors leveraging additive‐manufactured knitting technology. By exploring the fundamental relationships between loop‐scale structural features and knit‐scale mechanical properties, both numerical simulations and experimental studies are carried out to investigate how topological loop‐patterns govern the deformation mechanisms of 3D‐knitted fabric architectures. Upon comparing the structural characteristics and mechanical properties of various knitted patterns, the rib‐knits featuring a distinctive bilayer configuration show a particular elastic deformation process spanning three distinct stages, including structure unfolding, geometric extension, and material stretching. Based on this understanding, 2 + 2 rib‐knitted fabric architecture for a stretchable conductor is constructed, in which conductive EGaIn liquid‐metals are coated onto polytetrafluoroethylene (PTFE) fibers with polymethacrylate (PMA) serving as the intermediate adhesive. The resultant EGaIn@PMA/PTFE fabric (EP 2 F) architecture demonstrates remarkable conductivity (≈5.02 × 10 3 S cm −1 ) and stability, even after stretching up to 750% strain (≈4.76 × 10 3 S cm −1 , conductivity variation less than 5%), along with high mechanical strength, as evidenced by a fracture stretching stress exceeding 400 MPa. The mechanical performances of the as‐fabricated EP 2 F architecture can be further tailored across optimized knit patterns and fiber materials. This work would provide a productive and systematic strategy for designing stretchable conductors with practical applications in advanced wearable electronics.