Core–sheath structured polystyrene‐ethylene‐butene‐styrene/carbon nanotubes/carbonyl iron particlecomposite fiber with high stretchability for strain and magnetic field dual‐mode sensing

Abstract To meet the requirement of high stretchability, high sensitivity, and multifunction for flexible sensors, core–sheath structured polystyrene‐ethylene‐butene‐styrene (SEBS)/carbon nanotubes (CNTs)/carbonyl iron particle (CIP) fiber with SEBS/CNTs as the sheath and SEBS/CIP as the core was prepared through wet spinning. The contents of CNTs and CIP in the composite fiber were adjusted by changing the extrusion speed of the SEBS/CNTs and SEBS/CIP spinning solutions. The morphology, electromechanical sensing, and magnetic precepting performances of the fiber were studied. The SEBS/CNTs/CIP fiber sensor showed high stretchability with a maximum strain sensing range of 0%–216.9%, high sensitivity with a gauge factor (GF) of up to 1068.28, as well as excellent durability. In addition, the SEBS/CNTs/CIP fiber sensor exhibited excellent magnetic sensing performance by changing the relative resistance of 35.2% with a magnetic flux density variation of 1.2 T. The applications of SEBS/CNTs/CIP fiber in stretchable circuits, human body motion monitoring, and magnetic field perception were demonstrated. Highlights SEBS/CNTs/CIP fiber for strain and magnetic field sensing was fabricated. The SEBS/CNTs/CIP fiber sensor could sense 216.9% strain with GF up to 1068.28. Relative resistance of SEBS/CNTs/CIP fiber sensor changed by 35.2% under 1.2 T. SEBS/CNTs/CIP fiber was used in human motion monitoring and magnetic perception.