Droplet impact on asymmetric hydrophobic microstructures
arXiv:2203.04627 · doi:10.1021/acs.langmuir.2c00561
Abstract
Textured hydrophobic surfaces that repel liquid droplets unidirectionally are found in nature such as butterfly wings and ryegrass leaves and are also essential in technological processes such as self-cleaning and anti-icing. However, droplet impact on such surfaces is not fully understood. Here, we study, using a high-speed camera, droplet impact on surfaces with inclined micropillars. We observed directional rebound at high impact speeds on surfaces with dense arrays of pillars. We attribute this asymmetry to the difference in wetting behavior of the structure sidewalls, causing slower retraction of the contact line in the direction against the inclination compared to with the inclination. The experimental observations are complemented with numerical simulations to elucidate the detailed movement of the drops over the pillars. These insights improve our understanding of droplet impact on hydrophobic microstructures and may be a useful for designing structured surfaces for controlling droplet mobility.
arXiv comment24 pages, 9 figures
References in corpus (12)
- Pancake bouncing on superhydrophobic surfaces
- Drop Splashing on a Dry Smooth Surface
- Bouncing or sticky droplets: impalement transitions on superhydrophobic micropatterned surfaces
- Symmetry-breaking in drop bouncing on curved surfaces
- On the spreading of impacting drops
- Drop impact upon micro- and nanostructured superhydrophobic surfaces
- Maximal air bubble entrainment at liquid drop impact
- Ultrafast Interference Imaging of Air in Splashing Dynamics
- Droplet Impact Dynamics on Micropillared Hydrophobic Surfaces
- Impact of a Viscous Liquid Drop
- Droplet impact on surfaces with asymmetric microscopic features
- Droplet leaping governs microstructured surface wetting