Experimental investigation on the operating variables of a near-field electrospinning process via response surface methodology

The past decade has seen tremendous advances in producing nanofibers and nanowires from a variety of materials for applications in sensors, photovoltaic devices and regenerative medicine. Nano and sub-micron fibers produced from a conventional electrospinning process are relatively inexpensive to produce but result in entangled and randomly oriented fibers. In this research, we have utilized a modified form of the electrospinning process, wherein polymeric fibers of Poly-caprolactone (PCL) are deposited in controlled pattern orientations by the ‘near-field electrospinning’ process. The process variables are interdependent and greatly influence the final deposition and diameters of the fibers. Response Surface Methodology (RSM) was used to obtain a quantitative and systematic understanding of the near-field deposition process and its relationship with the process parameters. A response surface function was empirically determined with fiber diameter as the observed response and the deposition parameters as the variables. Fibers of diameter ranging for 500–1500 nm were produced with a reasonable R2 value of 0.74, which indicates approximately seventy five percent of the variation in the response variable can be explained by the explanatory variables and the rest by the inherent process variability.