Zhang Yi, Gan Yang, Zhang Liwen, Zhang Deyuan, Chen Huawei
School of Mechanical Engineering and Automation, Beihang University, Beijing 100191, China.
Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University, Beijing 100191, China.
Micromachines (Basel). 2020 Oct 30;11(11):978. doi: 10.3390/mi11110978.
Unidirectional liquid spreading without energy input is of significant interest for the broad applications in diverse fields such as water harvesting, drop transfer, oil-water separation and microfluidic devices. However, the controllability of liquid motion and the simplification of manufacturing process remain challenges. Inspired by the peristome of , a surface-tension-confined (STC) channel with biomimetic microcavities was fabricated facilely through UV exposure photolithography and partial plasma treatment. Perfect asymmetric liquid spreading was achieved by combination of microcavities and hydrophobic boundary, and the stability of pinning effect was demonstrated. The influences of structural features of microcavities on both liquid spreading and liquid pinning were investigated and the underlying mechanism was revealed. We also demonstrated the spontaneous unidirectional transport of liquid in 3D space and on tilting slope. In addition, through changing pits arrangement and wettability pattern, complex liquid motion paths and microreactors were realized. This work will open a new way for liquid manipulation and lab-on-chip applications.
无需能量输入的单向液体铺展在诸如集水、液滴转移、油水分离及微流控装置等众多领域的广泛应用中具有重大意义。然而，液体运动的可控性以及制造工艺的简化仍然是挑战。受[某种生物]口缘的启发，通过紫外线曝光光刻和部分等离子体处理，轻松制造出了具有仿生微腔的表面张力受限（STC）通道。通过微腔与疏水边界的结合实现了完美的不对称液体铺展，并证明了钉扎效应的稳定性。研究了微腔结构特征对液体铺展和液体钉扎的影响，并揭示了其潜在机制。我们还展示了液体在三维空间和倾斜坡面上的自发单向传输。此外，通过改变凹坑排列和润湿性模式，实现了复杂的液体运动路径和微反应器。这项工作将为液体操控和芯片实验室应用开辟一条新途径。
