Abstract The ability to directly modify the topology of a surface with three-dimensional micron-scale features provides both a mechanism of controlling how it interacts with the surrounding environment and the potential to impart functional features. Using direct material jetting based additive manufacturing technologies, we report the direct printing of microstructures onto aluminium coupons previously finished with polyurethane (PU) coatings where the overcoat window proved crucial for this process. The effect of PU coating's age on the development of strong interfacial interactions and hence the level of adhesion achieved between the photopolymer and the topcoat was explored. With aging, the PU coatings were shown to increase in cross-link density which resulted in reduced levels of adhesion with the photopolymer observed. This was reflected in changes in surface energy hence surface chemistry via XPS analysis. Changes in the interfacial interactions were qualitatively examined through SEM analysis of the photopolymer – PU coating interface which showed localized debonding (de-wetting) of the photopolymer when printing was performed on aged PU topcoats.

中文翻译：

---

使用材料喷射技术对有机基材进行表面拓扑修饰

摘要 直接修改具有三维微米级特征的表面拓扑结构的能力既提供了一种控制其与周围环境相互作用的机制，又提供了赋予功能特征的潜力。使用基于直接材料喷射的增材制造技术，我们报告了将微观结构直接打印到先前用聚氨酯 (PU) 涂层完成的铝试样上，其中外涂层窗口被证明对这一过程至关重要。研究了 PU 涂层的使用年限对强界面相互作用的发展以及光敏聚合物和面漆之间达到的附着力水平的影响。随着老化，PU 涂层的交联密度增加，导致与所观察到的光聚合物的粘附水平降低。这反映在表面能的变化中，因此通过 XPS 分析的表面化学。通过对光敏聚合物 - PU 涂层界面的 SEM 分析定性检查界面相互作用的变化，当在老化的 PU 面漆上进行印刷时，该界面显示光敏聚合物的局部脱粘（去湿）。