Melt electrowriting (MEW) is an advanced additive manufacturing technology that produces high-resolution scaffolds for medical applications. Although there are many valuable parameter groups for MEW, the corresponding principles need to be clarified to improve the success of printing high-fidelity scaffolds. To this end, we investigate the print limit of MEW with respect to the minimum interfiber distance and the maximum print period based on a medical-grade poly(ε-caprolactone) material. The results indicate that relatively large turning loops and low turning speeds improve the print accuracy of the scaffolds; however, excessively large turning loops and low turning speeds result in fiber accumulation on the edge of the scaffolds, resulting in print failure. The turning loops with 500 μm in diameter and turning speeds of 0.625 × CTS (critical translation speed) can achieve well-defined MEW scaffolds with an interfiber distance down to 25 μm. For printing such high-resolution scaffolds, the constant printing process can last one week. Fiber placement gets random when the fiber diameter is larger than 2.5 μm, caused by the melt polymer degradation and shear thinning in the printing process. Additionally, we verify that the method of charge neutralization is not beneficial for improving the fiber overlay. This is a fundamental study clarifying the principles of printing high-resolution MEW scaffolds, being capable of extending the application of the MEW products.

中文翻译：

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使用熔体电写增材制造超高分辨率聚（ε-己内酯）支架

熔融电写 (MEW) 是一种先进的增材制造技术，可为医疗应用生产高分辨率支架。尽管MEW有许多有价值的参数组，但需要明确相应的原则，以提高打印高保真支架的成功率。为此，我们研究了基于医用级聚（ε-己内酯）材料的 MEW 在最小纤维间距离和最大打印周期方面的打印极限。结果表明，相对较大的转动环和较低的转动速度提高了支架的打印精度；然而，过大的转动环和过低的转动速度会导致纤维堆积在支架边缘，导致打印失败。直径为 500 μm 的转动环和 0.625 × CTS（临界平移速度）的转动速度可以实现纤维间距离低至 25 μm 的清晰 MEW 支架。对于打印如此高分辨率的支架，持续的打印过程可以持续一周。当纤维直径大于 2.5 μm 时，由于打印过程中熔融聚合物降解和剪切稀化，纤维排列会变得随机。此外，我们验证了电荷中和的方法不利于改善纤维覆盖层。这是一项基础研究，阐明了打印高分辨率MEW支架的原理，能够扩展MEW产品的应用。