Li Jiaqian, Zhou Xiaofeng, Li Jing, Che Lufeng, Yao Jun, McHale Glen, Chaudhury Manoj K, Wang Zuankai
Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Hong Kong, China.
Science and Technology on Microsystem Laboratory, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 865 Changning Road, Shanghai 200050, China.
Sci Adv. 2017 Oct 27;3(10):eaao3530. doi: 10.1126/sciadv.aao3530. eCollection 2017 Oct.
The last two decades have witnessed an explosion of interest in the field of droplet-based microfluidics for their multifarious applications. Despite rapid innovations in strategies to generate small-scale liquid transport on these devices, the speed of motion is usually slow, the transport distance is limited, and the flow direction is not well controlled because of unwanted pinning of contact lines by defects on the surface. We report a new method of microscopic liquid transport based on a unique topological structure. This method breaks the contact line pinning through efficient conversion of excess surface energy to kinetic energy at the advancing edge of the droplet while simultaneously arresting the reverse motion of the droplet via strong pinning. This results in a novel topological fluid diode that allows for a rapid, directional, and long-distance transport of virtually any kind of liquid without the need for an external energy input.
在过去二十年中，基于微滴的微流控技术因其多种多样的应用而引发了人们浓厚的兴趣。尽管在这些设备上产生小规模液体传输的策略有了快速创新，但由于表面缺陷导致接触线不必要的钉扎，运动速度通常较慢，传输距离有限，且流动方向控制不佳。我们报道了一种基于独特拓扑结构的微观液体传输新方法。该方法通过在液滴前进边缘将多余表面能有效转化为动能来打破接触线钉扎，同时通过强钉扎阻止液滴的反向运动。这产生了一种新型拓扑流体二极管，无需外部能量输入就能实现几乎任何种类液体的快速、定向和长距离传输。
