Department of Mechanical Engineering, City University of Hong Kong, Hong Kong, 999077, China.
Shenzhen Research Institute of City University of Hong Kong, Shenzhen, 518057, China.
Adv Mater. 2019 Apr;31(14):e1806501. doi: 10.1002/adma.201806501. Epub 2019 Jan 30.
The power of the directional and spontaneous transport of liquid droplets is revealed through ubiquitous biological processes and numerous practical applications, where droplets are rectified to achieve preferential functions. Despite extensive progress, the fundamental understanding and the ability to exploit new strategies to rectify droplet transport remain elusive. Here, the latest progress in the fundamental understanding as well as the development of engineered droplet rectifiers that impart superior performance in a wide variety of working conditions, ranging from low temperature, ambient temperature, to high temperature, is discussed. For the first time, a phase diagram is formulated that naturally connects the droplet dynamics, including droplet formation modes, length scales, and phase states, with environmental conditions. Parallel approaches are then taken to discuss the basic physical mechanisms underlying biological droplet rectifiers, and a variety of strategies and manufacturing routes for the development of robust artificial droplet rectifiers. Finally, perspectives on how to create novel man-made rectifiers with functionalities beyond natural counterparts are presented.
液滴的定向和自发输运能力在普遍存在的生物过程和众多实际应用中得到了揭示，其中液滴被整流以实现优先功能。尽管取得了广泛的进展，但对基本理解和利用新策略来整流液滴输运的能力仍然难以捉摸。在这里，讨论了在基本理解方面的最新进展，以及在各种工作条件下赋予卓越性能的工程化液滴整流器的发展，这些工作条件的范围从低温、环境温度到高温。首次制定了一个相图，该相图自然地将液滴动力学（包括液滴形成模式、长度尺度和相态）与环境条件联系起来。然后采取平行方法来讨论生物液滴整流器的基本物理机制，以及开发稳健的人工液滴整流器的各种策略和制造途径。最后，提出了如何创造具有超越自然对应物功能的新型人造整流器的观点。
