3D Printing of High-Resolution Multi-Layer Scaffolds With Melt Electrowriting

Abstract

3D printing of high-resolution scaffolds is a big challenge with Melt Electrowriting (MEW) due to the electrification of polymer fibers in the presence of the electric field, which causes electrostatic attraction among fibers and induces a jet lag during fiber deposition. These intrinsic process characteristics significantly affect the accurate deposition of fibers in small spacing. To address these challenges, an effective air pressure manipulation is devised, which controls Taylor cone dynamics, including its shape and stability at a range of air pressure values, to achieve small fiber diameters, thus minimizing trapped residual charges and, consequently, electrostatic phenomena. As for jet lag, an Extended Path Algorithm (EPA) is proposed, which suggests a comprehensive strategy to achieve the desired fiber spacing while efficiently suppressing jet lag at edges and turns. For accurate multi-layer fiber deposition, maintaining the ambient temperature below 16 °C is suggested, which can reduce the occurrence of commonly observed defects in multi-layer scaffolds. This three-way comprehensive strategy enables highly controlled multi-layer fiber deposition, achieving an unprecedented fiber spacing of 10 µm.