Design, Fabrication and optimization of collector set-ups for obtaining aligned nanofibers

Abstract

The objective of the electrospinning process is to obtain a fiber mesh or membrane which could be used as scaffolds in tissue engineering, wound healing, implant materials, drug delivery or medicinal materials. The fibers are formed on the collector plate due to the high potential electric field applied at the tip of needle which causes stretching of the polymer melt, in a spiral pathway and gets deposited on the collector plate. In conventional plate collector set-up, random nanofibers are deposited. However, aligned nanofibers are proved to be more useful for various specific purposes and difficult to obtain. Aligned nanofibres have found uses in skeletal tissue regeneration, neural cell seeding in scaffold, fuel cell electrolytes, electrochemical sensing, bone and blood vessel engineering, composite metal reinforcement and many other applications. The aim of this work is to alter the collector set-up designs to change the morphology of fibers obtained on the collector plate in an attempt to obtain aligned nanofibers. Briefly, ten different cost effective collector set-ups were fabricated. Electrospinning was performed using those collector plates and a polymer solution of Chloroform, Dichloromethane and Dimethyl formamide in 3:1 ratio was used. Other processing parameters such as applied voltage (12kV), feed rate (1mL/hr), tip collector distance (12 cm) were also optimized. The fibers obtained using the various collector setups were analysed using optical microscope and SEM. It was found that the alignment of the fibers obtained from the various collector set-ups varied with respect to each other. Best results were observed in case of grid shaped collector where the nanofibers were seen to be highly aligned. Alignment to a certain extent was also observed in case of static parallel electrodes collector set-up (ferrite magnetic strips) and in case of boat shaped collector for a small time period. This leaves us with the future prospect that the morphology of fibers can be further curtailed by modifying collector designs to obtain highly aligned nanofibers.

Keywords: Electrospinning, aligned, nanofiber, scaffold, collectors, collector design, SEM