Quincke oscillations of colloids at planar electrodes

TL;DR

This paper explores the oscillatory behavior of Quincke rollers, showing how micron-scale particles near planar electrodes can exhibit back-and-forth motion, advancing the understanding of active matter and enabling colloidal oscillator design.

Contribution

It reveals the conditions under which Quincke particles oscillate near electrodes, a novel dynamic not previously characterized in this context.

Findings

Quincke particles can oscillate near planar electrodes.

Oscillations depend on particle size and boundary layer thickness.

The work enables design of colloidal oscillators.

Abstract

Dielectric particles in weakly conducting fluids rotate spontaneously when subject to strong electric fields. Such Quincke rotation near a plane electrode leads to particle translation that enables physical models of active matter. Here, we show that Quincke rollers can also exhibit oscillatory dynamics, whereby particles move back and forth about a fixed location. We explain how oscillations arise for micron-scale particles commensurate with the thickness of a field-induced boundary layer in the nonpolar electrolyte. This work enables the design of colloidal oscillators.