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Updated: Nov 1, 2025
07:18
Measuring the Interaction Force Between a Droplet and a Super-hydrophobic Substrate by the Optical Lever Method
Published on: June 14, 2019
6.9K
Horizontal Motion of a Superhydrophobic Substrate Affects the Drop Bouncing Dynamics
Haiyang Zhan1, Chenguang Lu1, Cong Liu1
1Key Laboratory for Precision and Non-Traditional Machining Technology of Ministry of Education, Dalian University of Technology, Dalian 116024, China.
Physical Review Letters
|June 25, 2021
Summary
Water drops impacting moving superhydrophobic surfaces experience reduced contact times due to air entrainment. This study reveals new scaling laws for drop spreading and contact time, aiding in controlling water repellency.
Area of Science:
- Fluid dynamics
- Surface science
- Materials science
Background:
- Drop impact dynamics on stationary surfaces are well-understood.
- The behavior of drops impacting moving solids remains largely unexplored.
Purpose of the Study:
- To investigate the physical mechanisms of water drops impacting horizontally moving superhydrophobic surfaces.
- To uncover scaling relations for drop spreading and contact time.
Main Methods:
- Experimental observation of drop impacts.
- Theoretical analysis of fluid dynamics.
Main Results:
- A viscous force from air entrainment competes with capillary and inertia forces.
- Asymmetric drop elongation and reduced contact time were observed.
- Scaling relations were derived: Dmax/D0∼We^(1/4)Ca^(1/6) and τ/τ0∼Ca^(-1/6).
Conclusions:
- The study enhances understanding of drop-solid interactions on moving surfaces.
- Findings offer new avenues for active control of water repellency.
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