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Updated: Jun 19, 2026
11:51
Visually Based Characterization of the Incipient Particle Motion in Regular Substrates: From Laminar to Turbulent Conditions
Published on: February 22, 2018
Noisy swimming at low Reynolds numbers.
1Rudolf Peierls Centre for Theoretical Physics, University of Oxford, Oxford OX1 3NP, United Kingdom. jorn.dunkel@physics.ox.ac.uk
Summary
Swimmer size controls the balance between active swimming and passive Brownian motion in microswimmers. This study reveals three distinct movement regimes, crucial for understanding bacterial foraging and designing artificial microswimmers.
Area of Science:
- Physics of soft matter
- Microfluidics
- Statistical mechanics
Background:
- Microorganisms and artificial microswimmers exhibit complex motion from active swimming and Brownian motion.
- Understanding this interplay is key for biological processes and synthetic designs.
Purpose of the Study:
- To investigate how swimmer size influences the dynamics of active and diffusive motion.
- To analyze the behavior of a simplified linear three-sphere swimmer at low Reynolds numbers.
Main Methods:
- Derivation of analytical formulas from the Kirkwood-Smoluchowski and Langevin equations.
- Validation of theoretical results using numerical simulations in three dimensions.
Main Results:
- Formulas derived for orientation correlation time, mean velocity, and mean-square displacement.
- Identified three distinct regimes: Brownian motion (small times), quasiballistic (intermediate), and quasidiffusive (large times).
- Noise-induced rotation drives the transition to quasidiffusive behavior at larger timescales.
Conclusions:
- Swimmer size is a critical parameter regulating active and diffusive dynamics.
- Findings aid in understanding bacterial foraging strategies and developing efficient artificial microswimmers in complex fluids.
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