Selective liquid directional steering enabled by dual-scale reentrant ratchets  

作　　者：Jing Sun Xuezhi Qin Yuxin Song Zhenyu Xu Chao Zhang Wei Wang Zhaokun Wang Bin Wang Zuankai Wang 

机构地区：[1]Department of Mechanical Engineering,City University of Hong Kong,Hong Kong 999077,People’s Republic of China [2]Department of Mechanical Engineering,The Hong Kong Polytechnic University,Hong Kong 999077,People’s Republic of China [3]Shenzhen Institute of Advanced Technology,Chinese Academy of Sciences,Shenzhen 518055,People’s Republic of China

出　　处：《International Journal of Extreme Manufacturing》2023年第2期266-273,共8页极端制造（英文）

基　　金：financial support from the ITF(GHP/021/19SZ);Shenzhen Science and Technology Innovation Council (9240061 and JCYJ20200109143206663);National Natural Science Foundation of China (No.51975502);Research Grants Council of Hong Kong(No. C1006-20WF, No. 11213320);Science and Technology Planning Project of Guangdong Province (No.2021A0505110002);Shenzhen-Hong Kong Joint Innovation Project (No. SGDX2019091716460172)。

摘　　要：Achieving well-controlled directional steering of liquids is of great significance for both fundamental study and practical applications, such as microfluidics, biomedicine, and heat management. Recent advances allow liquids with different surface tensions to select their spreading directions on a same surface composed of macro ratchets with dual reentrant curvatures. Nevertheless, such intriguing directional steering function relies on 3D printed sophisticated structures and additional polishing process to eliminate the inevitable microgrooves-like surface deficiency generated from printing process, which increases the manufacturing complexity and severally hinders practical applications. Herein, we developed a simplified dual-scale structure that enables directional liquid steering via a straightforward 3D printing process without the need of any physical and chemical post-treatment. The dual-scale structure consists of macroscale tilt ratchet equipped with a reentrant tip and microscale grooves that decorated on the whole surface along a specific orientation. Distinct from conventional design requiring the elimination of microgrooves-like surface deficiency, we demonstrated that the microgrooves of dual-scale structure play a key role in delaying or promoting the local flow of liquids, tuning of which could even enable liquids select different spreading pathways. This study provides a new insight for developing surfaces with tunable multi-scale structures, and also advances our fundamental understanding of the interaction between liquid spreading dynamics and surface topography.

关 键 词：liquid spreading reentrant ratchet dual-scale structures 

分 类 号：TP391.73[自动化与计算机技术—计算机应用技术]