Carbon-Dots-Induced Microphase-Separated Polypyrrole Hydrogels with Ultrahigh Stretchability and Low Modulus for Soft Electronics

Flexible electronic devices have attracted considerable attention owing to their potential in wearable sensing, health monitoring, and soft robotics. However, developing conductive hydrogels that simultaneously possess high stretchability, low hysteresis, strong adhesion, and stable conductivity remained challenging due to the poor dispersibility of conductive polymers such as polypyrrole (PPy). In this study, a carbon dots (CDs)-induced microphase separation strategy was proposed to construct multifunctional conductive hydrogels. CDs regulate the polymerization behavior and dispersion state of PPy, promoting the formation of PPy-rich conductive domains within an oxidized hyaluronic acid (OHA)/polyacrylamide (PAM) network. The resulting microphase-separated architecture enhances interfacial coupling between conductive and elastic components, leading to improved electrical continuity and mechanical robustness. The optimized hydrogel exhibited a tensile strength of 77.56 kPa, a fracture strain exceeding 4300%, low energy loss (89%). The resultant POCP hydrogel demonstrated great potential for applications in wearable strain sensors, bioelectrodes, and flexible supercapacitors.