Key Laboratory of Precision Microelectronic Manufacturing Technology & Equipment of Ministry of Education , Guangdong University of Technology , Guangzhou 510006 , China.
School of Engineering , The Chinese University of Hong Kong , Shatin , Hong Kong.
ACS Appl Mater Interfaces. 2018 Oct 10;10(40):34735-34743. doi: 10.1021/acsami.8b11271. Epub 2018 Sep 25.
Directional liquid transport has significant domestic and industrial applications. Tapered objects have theoretically and experimentally been demonstrated to have the ability to spontaneously transport liquids. However, the transporting distance is limited, and consecutively and spontaneously transporting liquids has always been a challenge. In this work we proposed to exploit ladderlike tapered pillars, which are inspired by relay races, to increase the transport distance. These pillars were designed using a developed numerical model and fabricated by a novel alternating etching and coating method followed by wettability enhancement. We demonstrated through experiments that the resulting pillars could consecutively and spontaneously transport a liquid droplet at an average velocity of 0.139 m/s with a maximum acceleration of 5 g. The optimum window of the tilt angle range (0°-25°), contact angle (50°), and the chemical modification time (5 min) were obtained. Such ladderlike tapered pillars are able to improve the water-collection efficiency. These results may provide a new and systematic way to design and fabricate materials and structures for directional liquid transport.
定向液体输送在国内和工业上有重要的应用。理论和实验都证明了锥形物体具有自发输送液体的能力。然而，输送距离有限，连续和自发输送液体一直是一个挑战。在这项工作中，我们提出利用梯状锥形柱来增加输送距离，这些锥形柱是受到接力赛的启发而设计的。我们使用一种改进的数值模型来设计这些柱子，并采用一种新的交替蚀刻和涂层方法以及润湿性增强技术来制造。我们通过实验证明，所得到的柱子可以以 0.139 m/s 的平均速度连续且自发地输送液滴，最大加速度为 5 g。我们还获得了最佳的倾斜角度范围（0°-25°）、接触角（50°）和化学修饰时间（5 分钟）的窗口。这种梯状锥形柱能够提高集水效率。这些结果可能为设计和制造用于定向液体输送的材料和结构提供了一种新的、系统的方法。
