Active Particles Powered by Quincke Rotation in a Bulk Fluid

Area of Science:

• Soft Matter Physics
• Active Matter Physics
• Fluid Dynamics

Background:

• Dielectric particles in conducting fluids exhibit spontaneous rotation under DC electric fields via Quincke rotation instability.
• Particle rotation near surfaces can be converted to translation, creating model systems for active matter.
• Existing methods often require proximity to surfaces for rotation-to-translation conversion.

Purpose of the Study:

• To investigate the conversion of spontaneous Quincke rotation into spontaneous translation.
• To explore this conversion mechanism in the absence of confining surfaces.
• To utilize geometrical asymmetry as the driving factor for rotation-to-translation conversion.

Main Methods:

• Numerical simulations were employed to model particle behavior.
• Theoretical modeling was used to analyze the underlying physical principles.
• Focus on systems with geometrical asymmetry in the absence of surfaces.

Main Results:

• Demonstrated the conversion of spontaneous Quincke rotation into spontaneous translation.
• Achieved this conversion in a plane perpendicular to the applied DC electric field.
• Showcased the effectiveness of geometrical asymmetry in driving this phenomenon without surfaces.

Conclusions:

• Geometrical asymmetry is a viable mechanism to induce spontaneous translation from Quincke rotation.
• This provides a novel pathway for creating self-propelling particles without surface interactions.
• Opens new possibilities for designing and controlling active matter systems.