Synergistic combination of carbon-black and graphene for 3D printable stretchable conductors

Abstract

ABSTRACT Stretchable conductors are important ingredients in the new emerging wearable systems. Here, intrinsically stretchable con­ductors (ISCs) based on carbon nanomaterials with a good balance of properties are prepared through synergistic combination of graphene and carbon black (CB) into the matrices of thermoplastic polyurethane (TPU). The inks are prepared through mixing graphene and CB with adjustable mass ratios in TPU by ball-milling, which can be used for blade-coating or 3D-printing. The ISCs prepared by drying the inks at room temperature afford an initial conductivity of 12.5 S cm-1 with an elongation of 140%, or 62.5 S cm-1 with an elongation of 20%, comparable to the carbon nanotube based ISCs. The whole performance is better than those of composites with only one filler (graphene or CB), suggesting the synergistic effect between graphene and CB. Furthermore, the composites with binary fillers have stable electromechanical properties for 1000 cycles of stretching and releasing.