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Updated: Mar 2, 2026

Measuring the Interaction Force Between a Droplet and a Super-hydrophobic Substrate by the Optical Lever Method
Published on: June 14, 2019
van der Waals interaction between a moving nano-cylinder and a liquid thin film
René Ledesma-Alonso1, Elie Raphaël, Thomas Salez
1CONACYT - Universidad de Quintana Roo, Boulevar Bahía s/n, Chetumal, 77019, Quintana Roo, Mexico. rene.ledesma@uqroo.edu.mx.
Abstract:
We study the static and dynamic interaction between a horizontal cylindrical nano-probe and a thin liquid film. The effects of the physical and geometrical parameters, with a special focus on the film thickness, the probe speed, and the distance between the probe and the free surface are analyzed. Deformation profiles have been computed numerically from a Reynolds lubrication equation, coupled to a modified Young-Laplace equation, which takes into account the probe/liquid and the liquid/substrate non-retarded van der Waals interactions. We have found that the film thickness and the probe speed have a significant effect on the threshold separation distance below which the jump-to-contact instability is triggered. These results encourage the use of horizontal cylindrical nano-probes to scan thin liquid films, in order to determine either the physical or geometrical properties of the latter, through the measurement of interaction forces.
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