A simple model for nanofiber formation by rotary jet-spinning
Nanofibers are microstructured materials that span a broad range of applications from tissue engineering scaffolds to polymer transistors. An efficient method of nanofiber production is Rotary Jet-Spinning (RJS), consisting of a perforated reservoir rotating at high speeds along its axis of symmetry, which propels a liquid, polymeric jet out of the reservoir orifice. These jets undergo stretching and solidify forming nanoscale fibers. We report a minimal scaling framework complemented by a semi-analytic and numerical approach to characterize the regimes of nanofiber production using RJS. Our theoretical model is validated for the fiber radius as a function of experimentally tunable parameters. We summarize our findings in a phase diagram for the design space of continuous nanofibers as a function of process parameters, in good agreement with experiments and with natural implications for the production rates as well as in the morphological quality of fibers.