Real-time observation of Brownian motion and cluster movement of ferro- and non-magnetic particles in magnetic fluids

Cluster movements of ferro- and non-magnetic particles in magnetic fluids were investigated using optical microscope system and image processing system. Real-time visualizations of the Brownian motion of particles and the chain-like cluster movement of both types of particle were performed under a magnetic field. The principal objectives of this study were to clarify the applicability of the optical microscope system and image processing system, and to analyze the growth process of the cluster under magnetic field. The analysis of particle image was done using Particle Tracking Velocimetry (PTV). The results clarified that the real-time observation of Brownian motion and cluster movement of ferro- and non-magnetic particles in magnetic fluids can be carried out using the optical microscope system and the PTV image measurement. Independent continuous measurements with changing positions and velocity of the minute particle were made possible. The study concluded that the system can obtain satisfactory results on growth process measurement of cluster under a magnetic field.