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Updated: Dec 21, 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
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Contact time on curved superhydrophobic surfaces
Jeonghoon Han1, Wonjung Kim2, Changwoo Bae1
1Department of Mechanical Engineering, Kyung Hee University, Yongin 17104, Republic of Korea.
Physical Review. E
|May 20, 2020
Summary
Researchers developed a new model for water drop contact time on curved superhydrophobic surfaces. This model explains asymmetric spreading and can aid in designing surfaces for thermal applications.
Area of Science:
- Fluid Dynamics
- Surface Science
- Materials Science
Background:
- Water drops bouncing off superhydrophobic surfaces have a contact time determined by the Rayleigh inertial-capillary timescale.
- Contact time is altered on curved superhydrophobic surfaces due to asymmetric spreading, but the underlying physics remain unclear.
- Existing models fail to accurately predict contact time on curved superhydrophobic surfaces.
Purpose of the Study:
- To investigate the mechanism driving asymmetric drop spreading on curved superhydrophobic surfaces.
- To develop a predictive physical model for the contact time of water drops on curved superhydrophobic surfaces.
- To provide insights for designing superhydrophobic surfaces for thermal applications.
Main Methods:
- Proposed that asymmetric spreading is governed by the Coanda effect or inertia, dependent on the drop and curvature diameters.
- Developed a contact time model based on scaling analysis.
- Validated the model against experimental measurements across various impact velocities and curvature diameters.
Main Results:
- Identified the key factors influencing asymmetric spreading on curved superhydrophobic surfaces.
- The proposed scaling analysis-based model accurately predicts measured contact times.
- The model demonstrates success across a wide range of experimental conditions.
Conclusions:
- The study elucidates the mechanism of asymmetric spreading on curved superhydrophobic surfaces.
- The developed contact time model offers a robust tool for predicting drop-surface interaction.
- The findings support the optimized design of superhydrophobic surfaces for enhanced thermal management.
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