Expanding Melt‐Based Electrohydrodynamic Printing of Highly‐Ordered Microfibrous Architectures to Cm‐Height Via In Situ Charge Neutralization

Abstract

AbstractIt is a great challenge for melt‐based electrohydrodynamic (EHD) printing to fabricate cm‐height microfibrous scaffolds with uniform fiber diameter and highly‐ordered architectures due to inherent charge‐induced fiber repulsion and gradually‐reduced electrical strength. Here, a novel approach is presented that involves incorporating the in situ charge neutralization technique into the melt‐based EHD printing process. The addition of the charge elimination module can efficiently neutralize residual charges inside the EHD‐printed microfibers and minimize fiber–fiber repulsion to ensure precise fiber deposition. Computational simulation indicates that the applied voltage should increase ≈0.15 kV as the printed structure height increases 1 mm to maintain a relatively constant electrical strength. The implementation of these two strategies in melt‐based EHD printing successfully produces highly‐ordered fibrous architectures with a maximum height of 10.01 ± 0.18 mm and a uniform fiber diameter of 17.6 ± 1.3 µm. The resultant microfibrous architectures can guide large‐area cellular alignment in 3D and function as supporting frames to reinforce mechanically‐weak collagen hydrogel for engineering large‐volume cellular constructs. To the authors’ best knowledge, it is the first instance of directly producing cm‐height, highly‐ordered microfibrous architectures via melt‐based EHD printing with in situ charge neutralization and constant electrical strength capabilities for tissue‐engineering applications.