Cooperative Behavior and Pattern Formation in Mixtures of Driven and Nondriven Colloidal Assemblies

TL;DR

This study uses simulations to explore how driven and nondriven colloidal particles interact, revealing dynamic pattern formation like string structures influenced by external forces and particle density.

Contribution

It introduces a novel model of collective transport where driven particles induce effective attractions, leading to dynamic string formations in disordered colloidal assemblies.

Findings

Driven particles form intermittent string-like structures.

String velocity increases with the number of driven particles.

Stable string length depends on driving force and particle density.

Abstract

We simulate a disordered assembly of particles interacting through a repulsive Yukawa potential with a small fraction of the particles coupled to an external drive. Distortions in the arrangement of the nondriven particles produce a dynamically induced effective attraction between the driven particles, giving rise to intermittent one-dimensional stringlike structures. The velocity of a moving string increases with the number of driven particles in the string. We identify the average stable string length as a function of driving force, background particle density, and particle charge. This model represents a new type of collective transport system composed of interacting particles moving through deformable disorder.