Mathematical Modeling of a Polymer Jet in the Electrospinning Process

Electrospun fine fibers have widely attracted attention because of unique physical properties due to their microscopic structures. Sensitive handling is, however, required for fragile fine-fiber sheets. Productivity and related costs are also an issue to be solved. We thus developed a novel process of direct electrospinning, which deposits fine fibers directly on a target. To control the process adequately, fundamental understanding is desired for polymer jet dynamics. In a general electrospinning process, an electrified polymer jet initially forms a stable straight line and is then followed by unstable whipping motions. Theoretically there exist two different approaches to model the straight and the whipping motions, but the consistency of their results has not been well confirmed. We therefore performed consistent simulations for the straight and the whipping motion and obtained a reasonable result by applying a practical external electric field and aerodynamic effects. The simulation was applied to typical conditions of the direct electrospinning process. A fine-fiber film fabricated by the process provides stress-free feeling through unique properties of adhesion and compliance to skin deformation.