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Updated: Jul 31, 2025
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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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Wettability gradient-driven droplets with an applied external force
Leon Topp1, Lena Haddick1, Dominik Mählmann1
1University of Münster, Institute for Physical Chemistry, Correnstr. 28/30, 48149 Münster, Germany.
The Journal of Chemical Physics
|May 1, 2023
Summary
Droplet sliding velocity under combined forces is nearly constant, primarily influenced by the initial substrate
Area of Science:
- Physics
- Materials Science
- Surface Science
Background:
- Droplet sliding on homogeneous substrates is driven by external forces like gravity.
- Wettability gradients induce internal driving forces, enabling sliding without external input.
Purpose of the Study:
- Investigate droplet sliding dynamics under combined external and internal driving forces.
- Analyze limiting cases with single driving forces for comparison.
Main Methods:
- Molecular dynamics simulations were employed to model droplet behavior.
- Simulations examined droplet motion over substrates with varying wettability.
Main Results:
- Droplet velocity remained nearly constant during much of the sliding process over the wettability borderline.
- Effective mobility was mainly determined by the initial substrate's mobility at the receding contact line.
- Effective force comprised the external force plus a renormalized internal force, indicating enhanced dissipation with wettability gradients.
Conclusions:
- Receding contact line desorption is the rate-limiting step in droplet sliding.
- Wettability gradients introduce significant dissipation effects on droplet motion.
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