Nanotechnology Research Laboratory, Research School of Engineering, The Australian National University, Canberra, ACT, 2601, Australia.
Small. 2017 Apr;13(14). doi: 10.1002/smll.201603688. Epub 2017 Jan 30.
Manipulation of nanoliter droplets is a key step for many emerging technologies including ultracompact microfluidics devices, 3D and flexible electronic printing. Despite progress, contamination-free generation and release of nanoliter droplets by compact low-cost devices remains elusive. In the present study, inspired by butterflies' minute manipulation of fluids, the authors have engineered a superamphiphobic bionic proboscis (SAP) layout that surpasses synthetic and natural designs. The authors demonstrate the scalable fabrication of SAPs with tunable inner diameters down to 50 µm by the rapid gas-phase nanotexturing of the outer and inner surfaces of readily available hypodermic needles. Optimized SAPs achieve contamination-free manipulation of water and oil droplets down to a liquid surface tension of 26.56 mN m and a volume of 10 nL. The unique potential of this layout is showcased by the rapid and carefully controlled in-air synthesis of core-shell droplets with well-controlled compositions. These findings provide a new low-cost tool for high-precision manipulation of nanoliter droplets, offering a powerful alternative to established thermal- and electrodynamic-based devices.
纳升级液滴的操控是许多新兴技术的关键步骤，包括超紧凑微流控设备、3D 和柔性电子打印。尽管取得了进展，但通过紧凑、低成本的设备无污染地生成和释放纳升级液滴仍然难以实现。在本研究中，受蝴蝶对流体的微小操控的启发，作者设计了一种超越合成和天然设计的超疏液仿生喙（SAP）布局。作者通过快速气相纳米结构化，展示了具有可调节内径的 SAP 的可扩展制造，内径可低至 50 µm，该方法可利用现成的皮下注射针的外表面和内表面。优化后的 SAP 可以实现无污染的操控，液滴的表面张力低至 26.56 mN m，体积低至 10 nL。这种布局的独特潜力通过快速且精确控制的空气合成具有良好控制组成的核壳液滴得到了展示。这些发现为纳升级液滴的高精度操控提供了一种新的低成本工具，为基于热和电动力学的现有设备提供了一种强大的替代方案。
