A unique device for controlled electrospinning

The purpose of this research was to develop a system for controlled electrospinning of fibro-porous scaffolds for tissue engineering applications and to use this system to assess mesh architecture sensitivity to manufacturing parameters. The intent was to achieve scaffolds with well-controlled fiber diameters and inter-fiber spacing. To accomplish these objectives, a custom, closed-loop controlled, electrospinning system was built. The system was unique in that it had a collection surface that was independent of the electrodes. The system allowed independent manipulation and analysis of a number of manufacturing parameters: distance between the electrodes, distance from the nozzle to the collection surface, applied voltage, temperature of the melt, collection surface dielectric strength, and collection surface area. Morphological analysis of fabricated meshes showed that all test parameters significantly affected fiber diameter and inter-fiber spacing. Further, contrary to what is generally accepted in the electrospinning literature, voltage and temperature (inversely related to viscosity) were not the most significant parameters. Features of the collection surface, including dielectric strength and surface area, were more significant. This dominance is, in part, a reflection of the unique electrospinning system used. The collection surface, which was not connected to either of the electrodes, substantially altered the electric field between the electrodes. Using the developed controlled electrospinning system, thermoplastic polyurethane meshes with fiber diameters ranging from 5 to 18 microm with variability less than 1.8% were made; inter-fiber spacing ranged from 4 to 90 microm with variability less than 20.2%. The system has potential use in biomedical applications where meshes with controlled fiber diameter and inter-fiber spacing are of interest.