Scalable production of polymer nanofiber-based ropes, cables and coatings

Abstract

Recent innovations in the areas of smart textiles, bio-medical manufacturing, soft actuators and 3D printing of fiber-reinforced soft composites have highlighted the need to develop manufacturing processes for multi-material polymer nanofiber ropes and fibrous coatings. This thesis presents a single, scalable manufacturing process that allows for the continuous production of nanofiber-based ropes, cables micro-scale wire coatings and multi-material mats. The ropes, cables, and wire coatings are manufactured using a cascading electrospinning setup used in conjunction with a rotating ring collector and a take-up reel. The multi-material mats are realized by replacing the ring collector with a directed nozzle. The cascading design of the electrospinning units allows for the manufacture of cables with multiple sheath and material combinations. The tensile failure patterns of the cables reveal distinct effects of the multi-material sheaths. The stiffness of the micro-wire is seen to be critical for the coating application, in that the wire has to accommodate for the deflection encountered during the fiber deposition process. The adhesion strength and load-displacement profiles for the nanofiber coating interfaces are seen to be polymer-specific. For multi-material mats, co-spinning of the polymers results in a blended mechanical behavior for the composite mat. This is in contrast to the sequential ply failure observed in laminated mats. Overall, this novel process has applications to a wide area of applications in the biomedical, defense and manufacturing sectors.