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Colloidal swimmers near curved and structured walls
1Department of Chemistry, Columbia University, 3000 Broadway, New York, NY 10027, USA. ac2822@columbia.edu.
Soft Matter
|October 17, 2019
Summary
Colloidal swimmers near curved walls exhibit altered movement and broader angular distributions due to increased thermal fluctuations. This study details their behavior near curved and crystalline surfaces.
Area of Science:
- Physics
- Soft Matter Physics
- Fluid Dynamics
Background:
- Colloidal swimmers are microscale agents with self-propulsion.
- Their hydrodynamics near surfaces are critical for understanding collective behavior.
- Previous theories often simplified wall geometry.
Purpose of the Study:
- To investigate colloidal swimmer dynamics near arbitrarily curved walls using numerical simulations.
- To quantify hydrodynamic effects related to wall curvature.
- To explore swimmer behavior near colloidal crystalline surfaces.
Main Methods:
- Systematic numerical simulations based on lubrication theory.
- Extension of theoretical models to include arbitrary wall curvatures.
- Analysis of swimmer trajectories and angular distributions.
- Simulation of swimmer interactions with crystalline walls (free vs. locked rotation).
Main Results:
- Wall curvature significantly affects swimmer incident angles and broadens angular distributions.
- Increased curvature enhances the role of thermal fluctuations, altering swimmer motility.
- Backwards motion observed in pushers is also seen in pullers under specific conditions.
- Puller-like swimmers exhibit stochastic run-and-tumble dynamics near colloidal crystals.
Conclusions:
- Wall curvature is a key factor influencing colloidal swimmer behavior and motility.
- Thermal fluctuations play a more significant role with increasing wall curvature.
- Colloidal crystals induce complex dynamics, including run-and-tumble-like motion, in swimmers.
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