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arXiv · 2601.11424

Confinement-induced motion of ciliates

G. C. Antunes·C. Obst·H. Stark
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Abstract

The time dynamics of flagellar and ciliary beating is often neglected in theories of microswimmers, with the most common models prescribing a time-constant actuation of the surrounding fluid. By explicitly introducing a metachronal wave, coarse-grained to a sinusoidal surface slip velocity, we show that a spatial resonance between the metachronal wave and the corrugation of a confining cylindrical channel enables a ciliate to swim even when it cannot move forward in a bulk fluid. Using lubrication theory, we reduce the problem to the Adler equation that reveals an oscillatory and ballistic swimming regime. Interestingly, a ciliate can even reverse its swimming direction in a corrugated channel compared to the bulk fluid.

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BibTeXRIS

G. C. Antunes, C. Obst, H. Stark. 2026-01-16. Confinement-induced motion of ciliates. https://doi.org/10.1103/c9nx-h2jk

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