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Published on: April 19, 2018
Synchronization of rigid microrotors by time-dependent hydrodynamic interactions
Mario Theers1, Roland G Winkler
1Theoretical Soft Matter and Biophysics, Institute for Advanced Simulation and Institute of Complex Systems, Forschungszentrum Jülich, D-52425 Jülich, Germany.
Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics
|September 17, 2013
Summary
Hydrodynamically coupled microrotors exhibit synchronized rotational motion due to time-dependent fluid interactions. This study determines synchronization times and provides an analytical expression for this phenomenon.
Area of Science:
- Fluid dynamics
- Non-equilibrium statistical mechanics
- Micro-robotics
Background:
- Hydrodynamically coupled microrotors are systems of interest in micro-robotics and fluid dynamics.
- Understanding their collective behavior is crucial for designing micro-scale devices.
- Previous studies often used simplified fluid models, neglecting time-dependent interactions.
Purpose of the Study:
- To investigate the emergent dynamical behavior of hydrodynamically coupled microrotors.
- To demonstrate the role of time-dependent hydrodynamic interactions in rotor synchronization.
- To analyze the influence of external torques and rotor separation on synchronization.
Main Methods:
- Modeling two rotors confined in a plane and moving along circles driven by active forces.
- Describing the three-dimensional fluid using linearized, time-dependent Navier-Stokes equations.
- Numerically solving the underlying integrodifferential equations to extract synchronization times.
Main Results:
- Time-dependent hydrodynamic interactions were shown to lead to synchronization of rotational motion.
- The time dependence of the phase difference between the rotors was determined.
- Synchronization times were extracted for various external torques and rotor separations.
Conclusions:
- Time-dependent hydrodynamic interactions are a key factor in the synchronization of microrotor systems.
- The study provides a method for determining synchronization times and an analytical expression for it.
- This research contributes to the understanding of collective dynamics in active matter systems.

