Tracking Rotational Diffusion of Colloidal Clusters

TL;DR

This paper introduces a new method for tracking the rotational motion of colloidal clusters, combining rigid body transformations with existing particle tracking techniques, validated through simulations and real microscopy data.

Contribution

The paper presents a novel approach to measure rotational dynamics of colloidal clusters by extending conventional tracking methods with rigid body transformations.

Findings

Validated method with simulated Brownian clusters

Successfully tracked real colloidal cluster motion

Facilitates study of rotational dynamics in colloidal systems

Abstract

We describe a novel method of tracking the rotational motion of clusters of colloidal particles. Our method utilizes rigid body transfor- mations to determine the rotations of a cluster and extends conventional proven particle tracking techniques in a simple way, thus facilitating the study of rotational dynamics in systems containing or composed of colloidal clusters. We test our method by measuring dynamical properties of simulated Brownian clusters under conditions relevant to microscopy experiments. We then use the technique to track and describe the motions of a real colloidal cluster imaged with confocal microscopy.