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Adhesive Forces in Droplet Kinetic Friction on Liquidlike Surfaces

Glen McHale1,*, Sara Janahi1, Hernán Barrio-Zhang1, Yaofeng Wang1, Jinju Chen2, Gary G. Wells1, and Rodrigo Ledesma-Aguilar1

  • *Contact author: glen.mchale@ed.ac.uk
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Phys. Rev. Lett. 135, 204003 – Published 12 November, 2025

DOI: https://doi.org/10.1103/ljbc-k193

Abstract

Kinetic frictional forces resisting droplet motion often appear to be separate from surface wettability and adhesive forces. Here we show that such friction arises from a simple combination of the contact angle hysteresis and adhesive force. We show theoretically, and confirm using tilt angle experiments of droplets on liquidlike surfaces, the dependence of the coefficient of droplet-on-solid kinetic friction on system parameters. We also show that a molecular kinetic-type model can describe the observed nonlinear velocity-force relationship. Our findings provide a fundamental understanding of the relationship between droplet-on-solid friction, and wettability and liquid adhesion.

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Phys. Rev. Lett. 135, 204003– Published 12 November, 2025
  • Received 21 June 2025
  • Revised 23 August 2025
  • Accepted 16 October 2025
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.

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