Efficiency Manipulation of Filaments Fusion in UV‐Assisted Direct Ink Writing

This study systematically investigates the ultraviolet‐assisted direct ink writing (UV‐DIW) process, focusing on the influence of critical parameters, including UV intensity, the ratio of printing speed to ink extrusion rate (), and relative nozzle height (H/h), on filament fusion and structural morphology. The rheological behavior of photosensitive resin ink is analyzed, revealing that UV irradiation induces a fluid‐to‐solid transition critical for shape retention and structural integrity. The results demonstrate that UV intensity plays a pivotal role in controlling filament fusion, with insufficient curing causing filament sagging and excessive fusion, while higher UV intensities improve structural fidelity. Additionally, printability (Pr), calculated from cross‐sectional analysis, is used as a quantitative metric to assess filament fusion quality and structure preservation. Parameter phase diagrams are developed to visually map the relationships among printing variables, providing a framework for optimizing UV‐DIW conditions. The successful fabrication of dense solid blocks without filament interfaces highlights the potential of UV‐DIW for producing high‐quality, defect‐free 3D structures. This work provides valuable insights into parameter tuning, paving the way for advanced applications in manufacturing, biomedical engineering, and material science.