Colloidal particle electrorotation in a non-uniform electric field

TL;DR

This paper presents a model for colloidal particle behavior in non-uniform electric fields, detailing conditions for Quincke rotation, complex dynamics, and interactions, enabling studies of collective particle behavior.

Contribution

It introduces a new model capturing the dynamics of colloidal particles in non-uniform electric fields, including rotation and interaction effects.

Findings

Threshold conditions for Quincke rotation identified.

Particle dynamics transition from steady spinning to orbiting.

Complex trajectories in particle pairs due to combined effects.

Abstract

A model to study the dynamics of colloidal particles in nonuniform electric fields is proposed. For an isolated sphere, the conditions and threshold for sustained (Quincke) rotation in a linear direct current (dc) field are determined. Particle dynamics becomes more complex with increasing electric field strength, changing from steady spinning around the particle center to time-dependent orbiting motion around the minimum field location. Pairs of particles exhibit intricate trajectories, which are combination of translation, due to dielectrophoresis, and rotation, due to the Quincke effect. Our model provides a basis to study the collective dynamics of many particles in a general electric field.