An electrospray photolithographic patterning (EPP) process that integrates advantages of electrospray (ES) and digital light processing (DLP) for maskless fabrication of 3D porous microstructures is proposed here. First, monodisperse microparticles with controllable particle size produced by ES are deposited on a substrate to form a photoresist layer. Second, DLP exposure of the photoresist layer selectively irradiates the microparticles to form a desired pattern with complexity. Third, the repetitive steps of deposition and exposure enable layer‐by‐layer construction of a green part with embedded 3D patterns of irradiation. Finally, the irradiated microparticles are removed from the green part to form 3D particulate microstructures. With this process, freeform patterning of multiple micro‐electro‐mechanical system elements with controlled porosity, involving microfluidic channels, stamps, and power‐free pressure sensors is successfully demonstrated. The EPP process has a great technical potential for freeform and high‐throughput fabrication of multi‐layered porous microstructures in versatile applications such as micromixers, porous stamping, and microsensors.

中文翻译：

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电喷雾和数字光处理的集成，用于多孔微结构的自由图形化

本文提出了一种电喷雾光刻图案化（EPP）工艺，该工艺融合了电喷雾（ES）和数字光处理（DLP）的优势，可实现3D多孔微结构的无掩模制造。首先，将由ES产生的粒径可控的单分散微粒沉积在基板上以形成光致抗蚀剂层。第二，光致抗蚀剂层的DLP曝光选择性地照射微粒以形成复杂的期望图案。第三，重复的沉积和曝光步骤使具有嵌入式3D辐射图样的绿色零件能够逐层构造。最终，从生坯中去除被辐照的微粒，以形成3D微粒微观结构。通过这个过程 成功地证明了具有受控孔隙度的多个微机电系统元件的自由形式图案，涉及微流体通道，压模和无动力压力传感器。EPP工艺具有广泛的技术潜力，可用于微型混合器，多孔冲压和微传感器等多功能应用中的多层多孔微结构的自由形式和高通量制造。