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Gradient dynamics model for chemically driven running drops

delete2026-04-06
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PRE
AI
J
Justus Niehoff
F
Florian Voss *
U
Uwe Thiele
DOI:10.1140/epjs/s11734-026-02296-wdelete
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Abstract

Abstract

En 中文
We present a thermodynamically consistent model for chemically driven running drops on a solid substrate with reversible substrate adsorption of a wettability-changing chemical species. We consider drops confined to a vertical gap, thereby allowing us to first obtain a gradient dynamics description of the closed system, corresponding to a set of coupled dynamical equations for the drop profile and the chemical concentration profiles of species on the substrate and in both fluids (drop, ambient medium). Chemostatting the species in the drop and the ambient medium, we then derive a reduced model for the dynamics of the drop and the adsorbate on the substrate. When the externally imposed chemical potentials are distinct, the system is driven away from thermodynamic equilibrium, allowing for sustained drop self-propulsion across the substrate due to a wettability contrast maintained by chemical reactions. We numerically study the resulting running drops and show how they emerge from drift-pitchfork bifurcations.

Journal

T
The European Physical Journal Special Topics
IF:
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Papers:
446
Citations:
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Organization

I
Institute of Theoretical Physics
Scholars:
113
Papers: 93
Citations: 1.7K