Li Xinlei, Wang Chaowei, Hu Youdi, Cheng Zilong, Xu Tianyu, Chen Zhenrui, Yong Jiale, Wu Dong
CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei 230027, P. R. China.
ACS Appl Mater Interfaces. 2024 Apr 10;16(14):18154-18163. doi: 10.1021/acsami.4c00190. Epub 2024 Mar 28.
A strategy to manipulate droplets on the lubricated slippery surfaces using tribostatic electricity is proposed. By employing femtosecond laser-induced porous microstructures, we prepared a slippery surface with ultralow adhesion to various liquids. Electrostatic induction causes the charges within the droplet to be redistributed; thus, the droplet on the as-prepared slippery surfaces can be guided by electrostatic force under the electrostatic field, with controllable sliding direction and unlimited transport distance. The combination of electrostatic interaction and slippery surfaces allows us to manipulate droplets with a wide volume range (from 100 nL to 0.5 mL), charged droplets (including electrostatic attraction and repulsion), corrosive droplets, and even organic droplets with ultralow surface tension. In addition, droplets on tilted surfaces, curved surfaces, and inverted slippery surfaces can also be manipulated. Especially, the slippery surfaces can even allow the electrostatic interaction to manipulate alcohol with surface tension as low as 22.3 mN/m and liquid droplets suspended on a downward surface, which is not possible with reported superhydrophobic substrates. The features of slippery surfaces make the electrostatic manipulation successfully applied in versatile droplet manipulation, droplet patterning, chemical microreaction, transport of solid cargo, targeted delivery of chemicals, and liquid sorting.
提出了一种利用摩擦静电在润滑的光滑表面上操纵液滴的策略。通过采用飞秒激光诱导的多孔微结构，我们制备了对各种液体具有超低附着力的光滑表面。静电感应会使液滴内的电荷重新分布；因此，在静电场作用下，制备好的光滑表面上的液滴可以在静电力的引导下滑动，滑动方向可控且传输距离不受限制。静电相互作用与光滑表面的结合使我们能够操纵各种体积范围（从100 nL到0.5 mL）的液滴、带电液滴（包括静电吸引和排斥）、腐蚀性液滴，甚至是具有超低表面张力的有机液滴。此外，倾斜表面、弯曲表面和倒置光滑表面上的液滴也能被操纵。特别是，光滑表面甚至能让静电相互作用操纵表面张力低至22.3 mN/m的酒精以及悬浮在向下表面的液滴，这是已报道的超疏水基底无法做到的。光滑表面的这些特性使静电操纵成功应用于多种液滴操纵、液滴图案化、化学微反应、固体货物运输、化学物质的靶向递送以及液体分选。
