(161f) Free Surface Electrospinning From Drops On a Wire

The needle-based electrospinning process has long been employed to create unique fibrous materials that are applicable for wide range of fields such as filtration, tissue engineering, drug delivery systems, nanocomposites, and textiles. However, the production rate of needle-based electrospinning is rather low, which limits its ability to be industrialized and applied in large scale manufacturing. For this reason, new techniques are being investigated where jetting occurs from a free liquid surface without the aid of a needle or nozzle; we refer to such processes as ?free surface electrospinning.? Here, we consider ?drops-on-wire? systems where a wire (with diameter on the order of hundreds of microns) is passed through a polymeric solution that coats the wire uniformly. Due to Rayleigh instabilities, the thin film of solution breaks up in to droplets. In the presence of an electric field, the individual droplets deform and jetting occurs until the droplet is exhausted. High speed photography is used to study the initialization and lifetime of the jets. In addition, the electrical current drawn from the electrospun fibers can be measured. The flow rate and current of the free surface jetting from a wire is examined, and scaling relations are determined for comparison to those reported for needle-based electrospinning.