Chen Mojun, Lee Heekwon, Yang Jihyuk, Xu Zhaoyi, Huang Nan, Chan Barbara Pui, Kim Ji Tae
Department of Mechanical Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong, China.
Small. 2020 Apr;16(13):e1906402. doi: 10.1002/smll.201906402. Epub 2020 Feb 26.
Direct mass-transfer via liquid nanodroplets is one of the most powerful approaches for additive micro/nanofabrication. Electrohydrodynamic (EHD) dispensing has made the delivery of nanosized droplets containing diverse materials a practical reality; however, in its serial form it has insufficient throughput for large-area processing. Here, a parallel, nanoscale EHD method is developed that offers both improved productivity and material diversity in 3D nanoprinting. The method exploits a double-barreled glass nanopipette filled with material inks to parallelize nanodripping ejections, enabling a dual 3D nanoprinting process. It is discovered that an unusual electric field distribution created by cross talk of neighboring pipette apertures can be used to steer the microscopic ejection paths of the ink at will, enabling on-demand control over shape, placement, and material mixing in 3D printed nanostructures. After thorough characterizations of the printing conditions, the parallel fabrication of nanomeshes and nanowalls of silver, CdSe/ZnS quantum dots, and their composites, with programmed designs is demonstrated. This method is expected to advance productivity in the heterogeneous integration of functional 3D nanodevices in a facile manner.
通过液体纳米液滴进行直接传质是添加剂微纳制造中最强大的方法之一。电流体动力学（EHD） dispensing使包含多种材料的纳米级液滴的输送成为现实；然而，其串行形式对于大面积加工而言产量不足。在此，开发了一种并行的纳米级EHD方法，该方法在3D纳米打印中提供了更高的生产率和材料多样性。该方法利用填充有材料墨水的双管玻璃纳米移液器来并行化纳米液滴喷射，实现双3D纳米打印过程。研究发现，相邻移液器孔的串扰产生的异常电场分布可用于随意控制墨水的微观喷射路径，从而能够对3D打印纳米结构的形状、位置和材料混合进行按需控制。在对打印条件进行全面表征后，展示了银、CdSe/ZnS量子点及其复合材料的纳米网和纳米壁的并行制造以及编程设计。预计该方法将以简便的方式提高功能性3D纳米器件异质集成的生产率。
