Concurrent collection and post-drawing of individual electrospun polymer nanofibers to enhance macromolecular alignment and mechanical properties

The study reports a nanomanufacturing method that facilitates post-drawing of electrospun polymer nanofibers. Post-drawing is critical in conventional microfiber processing to enhance mechanical strength, but has been difficult to implement with nanofibers. Here, a parallel automated track collector was designed to permit continuous processing of thousands of individual nanofibers per minute under highly controllable drawing conditions. Post-drawing systematically induced macromolecular alignment and altered the chemical bond composition of polycaprolactone nanofibers with increasing draw ratio. The strength and stiffness of fibers with a draw ratio of 4 were enhanced by 7 and 15 times respectively and their mechanical properties exceeded previously reported values for conventional and nanoscale polycaprolactone structures.