Interfacial Modification and Dynamic Network Design: A Self‐Healing Conductive Composite Material for High‐Performance Flexible Electronics

To develop high‐performance flexible wearable sensor materials, this study prepared amino‐functionalized graphene oxide (AGO) and amino‐functionalized carbon nanotubes (ACNTs) by modifying graphene oxide (GO) and carboxylated carbon nanotubes (COOH‐CNTs) with diethylenetriamine. This modification significantly improved the dispersion of the nanofillers within the polyurethane matrix and enhanced the interfacial bonding strength. Modified AGO and ACNTs were incorporated into a self‐healing polyurethane system based on Diels‐Alder (DA) chemical crosslinking via in situ polymerization, successfully yielding AGO/ACNTs/PU composites (hereafter denoted as AGCPU). The results demonstrate improved comprehensive properties: electrical conductivity reaching up to 5.2 × 10 −3 S/m, increasing with AGO content; tensile strength significantly increased while elongation at break exhibited controllable adjustment; as a strain sensor, it demonstrated high sensitivity (GF = 10.17) and good cyclic stability, enabling reliable monitoring of human joint flexion activities. This composite material provides an effective solution for balancing conductivity, self‐healing capability, and mechanical properties in flexible electronic devices, offering broad application prospects.