Physics
Document Type
Article
Abstract
We investigate the low-Reynolds-number propulsion of a slender elastic filament with a dipolar magnetic head actuated by an oscillating magnetic field in a viscous fluid by studying its strokes and net forward motion. To capture these dynamics, we employ an elastohydrodynamic (EH) framework that couples Euler-Bernoulli beam mechanics with resistive force theory. Unlike prescribed-kinematics models, filament shapes here emerge self-consistently from the actuation and the force and torque boundary conditions (BCs). We demonstrate that viscous boundary contributions are crucial for quantitative agreement and show that the swimming dynamics are governed by the EH length and a magneto-viscous-elastic stroke amplitude introduced here. The swimming speed is nonmonotonic with increasing ratio of the swimmer length to the EH length and is shown to reach a maximum when the swimmer length is on the order of the EH length. We further discuss the analytical limit in which the tail BCs can be described as free, and the limitations that arise when viscous contributions to the BCs are ignored. Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. https://creativecommons.org/licenses/by/4.0/
Publication Title
Physical Review Research
Publication Date
2026
Volume
8
Issue
4
ISSN
2643-1564
DOI
10.1103/gd8c-4t3q
Keywords
Elastohydrodynamic lubrication, elastohydrodynamics, filaments (lamp), viscosity, viscous flow
Repository Citation
Kapadia, Sohum; Chopin, Julien; and Kudrolli, Arshad, "Elastohydrodynamic propulsion of a magnetically actuated filament" (2026). Physics. 175.
https://commons.clarku.edu/faculty_physics/175
Cross Post Location
Student Publications
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Copyright Conditions
Kapadia, S., Chopin, J., & Kudrolli, A. (2026). Elastohydrodynamic propulsion of a magnetically actuated filament. Physical Review Research, 8(4), 043032.
