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Tunable colloidal spinners: Active chirality and hydrodynamic interactions governed by rotating external electric
Pavel A Libet1, Egor V Yakovlev1, Nikita P Kryuchkov1
1Centre for Soft Matter and Physics of Fluids, Bauman Moscow State Technical University, 2nd Baumanskaya Street 5, 105005 Moscow, Russia.
The Journal of Chemical Physics
|July 26, 2024
Summary
Colloidal particles in rotating electric fields exhibit tunable rotation, enabling new chiral active soft matter. This research explains particle rotation mechanisms and hydrodynamic forces governing pair precession.
Area of Science:
- Soft Matter Physics
- Colloid Science
- Microfluidics
Background:
- Microparticle rotation in liquids is crucial for microreactors, biotechnology, and understanding chiral active soft matter.
- Chiral active soft matter involves particles with rotational handedness, breaking microscopic mirror symmetry.
Purpose of the Study:
- To investigate the rotational dynamics of individual colloidal particles and particle pairs in rotating electric fields.
- To elucidate the underlying mechanisms of particle rotation and precession.
- To explore colloidal suspensions as a novel class of tunable chiral soft active matter.
Main Methods:
- Utilizing numerical simulations to model particle behavior.
- Conducting experiments with silica particles in a water-based solvent.
- Analyzing the time lag between applied electric fields and particle polarization.
Main Results:
- Individual colloidal particles rotate due to a time lag in polarization response to external electric fields.
- The tunable rotation of individual particles governs the precession of particle pairs and triplets.
- Hydrodynamic forces are key in explaining the observed collective particle motion.
Conclusions:
- Colloidal suspensions in rotating electric fields can be engineered as tunable colloidal spinners.
- The developed theoretical framework and experimental findings open new avenues for soft active matter research.
- These systems offer potential for novel applications in microfluidics and biotechnology.
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