Effects of scaffold design parameters on the printing accuracy for melt electrowriting

Melt electrowriting (MEW), a high-resolution additive manufacturing technique, has been used to fabricate high-fidelity fibrous scaffolds. However, the printing accuracy of MEW is deteriorated by the occurrence of fiber deviation phenomena during the scaffold-fabrication process, which limits a broader application of this technique. Herein, an efficient universal index (Ip), along with an evaluation protocol is advanced to evaluate the printing accuracy of MEW. Then, experimental results show that key scaffold design parameters (fiber diameter (d(f)), inter-fiber distance (S-f), and layer number (N)) can affect the value of I-p significantly. In general, the increase of d(f) and N and the decrease of S-f can lead to inferior printing accuracy, accompanied by a decrement in Ip values. Moreover, the interplay between d(f) and S-f on the printing accuracy is further analyzed based on a variable k (S-f over d(f)). The variables k and N are subsequently identified as the two fundamental scaffold design parameters that affect the printing accuracy. Lastly, residual charge densities entrapped in the scaffolds are measured, thereby furnishing mechanistic insights into the effects of charge on the printing accuracy.

Automated summary

This article introduces an effective index and evaluation protocol for evaluating the printing accuracy of melt electrowriting (MEW), and investigates the impact of scaffold design parameters on the printing accuracy. Experimental results show that fiber diameter, inter-fiber distance, and layer number significantly affect the printing accuracy. Additionally, the interaction between fiber diameter and inter-fiber distance also influences the printing accuracy.