Macroscopic assembly of flexible and strong green graphene fibres

Graphene fibres have great potential in future wearable electronics due to their promising thermal and electrical properties. However, fibre brittleness limits their implementation and researchers are still seeking easily scalable and eco-friendly production methods. Here we propose a green and continuous wet-spinning assembly approach to continuously spin flexible graphene oxide (GO) fibres. Highly stable aqueous GO suspensions up to 40 mg mL^-1 are achieved and GO fibres are spun from highly oriented liquid crystals through a customized continuous fibre production line. As-spun GO fibres with specific ultimate tensile strength of 7 N/tex show strain to failure (%) of 10%; subsequent NaBH₄ chemical reduction gives graphene fibres with electrical conductivity of 214 S cm^-1. The scalable production presented here facilitates flexible, strong and electrically conductive graphene fibres, which have emerged as promising graphene based electronic textiles and sensors.