Microfluidic Spinning of PEDOT:PSS Microfibers for Nerve Guidance Conduits

Abstract Peripheral nerve injury is associated with severe loss of life quality, often requiring surgical intervention. Nerve guidance conduits (NGCs) support nerve regeneration by guiding axonal outgrowth and Schwann cell migration. Conductive NGCs are of high interest, as they mimic the healthy nerve, thus improving therapeutic outcomes. This study presents a microfluidic spinning process for the fabrication of poly(3,4‐ethylene dioxythiophene) polystyrene sulfonate (PEDOT:PSS) microfibers. A microfluidic polydimethylsiloxane (PDMS) chip with an in‐chip direct laser written nozzle is fabricated and used to spin fibers from a commercially available PEDOT:PSS solution. The fiber diameter can be set precisely from 1.2 to 3 µm by adjusting the flow rates of the spinning dope and shear fluid. The fiber's mechanical properties are measured through tensile tests and nanoindentation, and are in the range of fibrin fibers that play a crucial role in natural nerve regeneration. The fibers are electrically conductive (6.38 ± 1.93S cm⁻¹) and electrochemically stable in the range relevant for stimulation, confirmed by cyclic voltammetry. Cultivation of L929‐cells confirms non‐cytotoxicity, live‐cell imaging shows adhesion to and migration on the microfibers. Microfluidically spun PEDOT:PSS microfibers are a promising material for the use as conductive NGCs or neural electrodes.