Structure-tunable graphene oxide fibers via microfluidic spinning route for multifunctional textiles

Bicomponent functional fibers with tunable structures are deemed as the promising building blocks for flexible asymmetric wearable devices and actuators. However, tunable structures of bicomponent fiber cannot be facilely achieved via conventional spinning routes. Herein, we developed a new strategy for structure-tunable fabrication of graphene oxide/alginate bicomponent fibers with different cross-section shapes via the microfluidic spinning route. Four distinct radial cross-section formations of bicomponent fibers: skin-core, eccentric structure, sandwich shapes and reverse core construction, are easily and instantaneously achieved through adjusting some basic parameters of the microfluidic spinning route. Computational fluid dynamics method is also utilized to simulate the flow behavior in the microfluidic channels during the microfiber shaping process. The structural fibers possessed unique properties corresponding to its structure configurations, i.e., skin-core shaped fibers exhibited the good tensile strength (235 MPa), while fibers with reverse core construction show admirable electrical conductivity (2000 S m−1) and outstanding electrochemical performance. This microfluidic spinning strategy offers a facile and environmental-friendly route to fabricate structure-tunable fibers without replacing the spinning templates, and provide a novel path to achieve flexible asymmetric wearable devices and actuators.