Highly-ordered assembly sheath layers of graphene coaxial fibers for high-performance wearable devices

• Published in: Sensors and actuators. A. Physical. Vol. 303; p. 111840
• Main Authors: Li, Ping, Wu, Wen, Xu, Jia, Cao, Jianda, Zhang, Huanxia
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.03.2020; Elsevier BV
• Subjects: Coagulation; Conductivity; Core-sheath structure; Electrical resistivity; Electrodes; Elongated structure; Fibers; Graphene; Graphene fibers; High strength; Highly-ordered; Sheaths; Smart sensors; Stretchability; Tug-of-war effect; Wearable devices; Wearable technology; Graphene fibers; Highly-ordered; Tug-of-war effect; Wearable devices; Core-sheath structure
• ISSN: 0924-4247; 1873-3069
• DOI: 10.1016/j.sna.2020.111840

[Display omitted] •Successfully prepared core-sheath structure graphene fibers with clear interface.•A flat and dense structure of sheath layers was formed under the tug-of-war effect.•The prepared coaxial graphene fibers showed good longitudinal electrical properties.•GCFs flexible conductive devices exhibited good stability and durability. Graphene fibers (GF) have broad application prospects in the fields of supercapacitors, electrodes, stimuli response sensors, and smart wearables. However, previously reported graphene-based fibers generally have low toughness and poor stretchability, which may limit possible applications. Here, we prepared novel high-strength, -stretch, and -conductivity graphene fibers with dense and highly-ordered sheath layers and a porous core structure. This was prepared by an efficient one-step coaxial wet-spinning method, which forms the rapid traction of the core layers on the sheath layers by the speed difference of the former, which is faster than the latter. The fiber surface was also subjected to the scouring force of the coagulation bath when the spinning solution was sprayed out of the spinning hole. The tug-of-war effect of these two opposing forces reacts on the curved graphene sheets, which made the graphene layers gradually straighten out, so that the sheath is efficiently and orderly aligned. The elongation of the high-strength GF with a core-sheath structure was effectively improved by approximately double, which was much higher than the previous research results. Moreover, high strength was maintained, and electrical stability was observably increased due to the core-sheath structure of the fibers. Such fibers also exhibited very stable electrical resistance during radial compression and tension cycles. Furthermore, we demonstrated the application of the fibers in wearable flexible devices.