Multiple-Droplet Selective Manipulation Enabled by Laser-Textured Hydrophobic Magnetism-Responsive Slanted Micropillar Arrays with an Ultrafast Reconfiguration Rate

作者：Wu, Sizhu; Li, Dayu; Zhang, Juan; Zhang, Yiyuan; Zhang, Yuxuan; Li, Shuyi; Chen, Chao; Guo, Sijia; Li, Chuanzong^*; Lao, Zhaoxin^*

来源：Langmuir : the ACS journal of surfaces and colloids , 2023.

DOI：10.1021/acs.langmuir.2c02944

• WETTABILITY GRADIENT
• SURFACES
• WATER
• TRANSPORT
• FILM

Biomimetic structures based on the magnetic response have attracted ever-increasing attention in droplet manipulation. Till now, most methods for droplet manipulation by a magnetic response are only applicable to a single droplet. It is still a challenge to achieve on-demand and precise control of multiple droplets (>= 2). In this paper, a strategy for on-demand manipulation of multiple droplets based on magnetism-responsive slanted micropillar arrays (MSMAs) is proposed. The Glacomodified superhydrophobic surface is the basis of multiple-droplet manipulation. The droplet's motion mode (pinned, unidirectional, and bidirectional) can be readily fine-tuned by changing the volume of droplets and the speed of the magnetic field. The rapid movement of droplets (10-80 mm/s) in the horizontal direction is realized by the unidirectional waves of the micropillar array driven by a specific magnetic field. The bending angle of micropillars can be rapidly and reversibly adjusted from 0 to 90 degrees under the action of a magnetic field. Meanwhile, the liquid-involved light, electric switch, and biomedical detection can be designed by manipulating the droplets on demand. The superiority of MSMAs in multiple-droplet programmable manipulation opens up an avenue for applications in microfluidic and biomedical engineering.

• 单位
  中国科学院; 吉林大学