Development and validation of a dual-polarity electrospinning device for reproducible nanofiber fabrication

Electrospinning is a versatile technique for producing micro- and nanofibrous materials; however, conventional single-polarity configurations often suffer from jet instabilities and limited control over fiber deposition due to bending (whipping) dynamics. In this work, a low-cost dual-polarity electrospinning platform was designed, constructed, and experimentally validated using independently controlled positive and negative high-voltage power supplies. A direct comparison between conventional single-polarity and dual-polarity operation was performed using poly( \(ε\) -caprolactone) (PCL) solutions processed under identical experimental conditions. Optical microscopy revealed that the dual-polarity configuration produced substantially smaller and more localized fiber-deposition areas, indicating improved jet confinement and deposition control. To investigate the underlying mechanism, finite-element simulations were conducted using COMSOL Multiphysics. Contrary to the common assumption that dual-polarity operation enhances performance through higher electric-field intensity, simulations showed that equivalent potential differences generate similar electric-field magnitudes in both configurations. The observed improvements are therefore consistent with a redistribution of electrostatic stresses, which promotes a modified electrostatic environment and modifies the balance between electrostatic, capillary, and viscoelastic forces acting on the jet. Fourier transform infrared spectroscopy and thermal analysis confirmed that exposure to high electric fields did not induce detectable polymer degradation. These findings provide experimental and numerical evidence that dual-polarity electrospinning improves jet stability and deposition control primarily through electrostatic stress redistribution rather than through a simple increase in electric-field strength, offering a physically grounded strategy for optimizing electrospinning performance.