Development of a Low-Cost Electrospinner for Fabrication of Polyacrylonitrile Fibers as a Precursor to Flexible Carbon Neural Electrodes.

Carbon has recently gained attention as a possible alternative to metal-based neural electrodes. In addition to being ideal for neuronal recording, carbon's chemical inertness, electrochemical stability, and ability to coexist with medical imaging techniques without introducing significant imaging artefacts presents opportunities to use carbon-based electrodes for stimulation also. For flexible interconnections, carbon fibers with a glassy carbon crystalline state are of interest. Electrospinning is the most effective method of fabricating polymer-based nanofibers which are then pyrolyzed into carbon fabric. Here we present the build process of an electrospinner to perform characterization testing on fabricated carbon fibers, from electrospinning to pyrolysis; with the purpose of demonstrating how, through varying voltage and flow rate parameters, we can control fiber morphology. These parameters, along with relative humidity, were found to be linked in their impacts on fiber morphology, but demonstrate that through optimization, fiber morphology can be controlled. Pyrolysis was found to have only minor effects on fiber morphology, but further reduces fiber diameters.