Contactless magnetic manipulation of magnetic particles in a fluid

Abstract

The objective of this study was to demonstrate contactless magnetic manipulation of a magnetic particle along a designated orbit among other magnetic particles suspended in a fluid at rest or in motion, and also to understand the behaviors of those surrounding particles during the contactless magnetic manipulation. In addition, the possibility of breaking up chains of clustered magnetic particles under such conditions was also studied. We first describe contactless magnetic manipulation of magnetic particles by feedback control in which the feedback signal was the measured coordinates of the tracked particle. By the feedback control monitoring the location of the tracked particle using a high-speed image analyzer, the reach of the dipole magnetic field created by the magnetized magnetic particles could be kept relatively small. As a result, the tracked magnetic particle could be dragged along the designated orbit by magnetic force. Second, we describe the breaking up of chains of clustered magnetic particles using an alternating magnetic force. The results showed that chain-clustered magnetic particles that had been aggregated under the condition of contactless magnetic manipulation could be broken up reproducibly by an alternating magnetic field. These results constitute useful information for advancements in the handling of magnetic micro- or nanoparticles.