Dresden 2009 – scientific programme

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DY: Fachverband Dynamik und Statistische Physik

DY 16: Fluid dynamics I

DY 16.12: Talk

Wednesday, March 25, 2009, 17:45–18:00, ZEU 255

Interactions of Magnetic Particles in Non-Magnetic Liquids — •Alexander Weddemann, Simone Herth, and Andreas Hütten — Bielefeld University, Universitätsstraße 25, D-33615 Bielefeld, Germany

Magnetic particles on the micro- or nanoscale, so called magnetic beads, have a growing number of different applications in many different physical, chemical or medical fields, e.g. as contrast agents or drug carriers. One of their most important features is the possibility to manipulate them in e.g. microfluidic devices by an external magnetic field. However, external fields also align the magnetic moment vectors, which leads to high forces between particles on short distances inducing very strong fluid flows. Especially, though strong magnetic forces occur in these systems, they eventually do not exceed the hydrodynamic interactions of the particles anymore. To investigate the different force contributions, the behaviour of particles in a rotational or alternating homogenous magnetic field is analysed. We discuss the dependency of particle motion with respect to field frequency as well as the particle properties, e.g. size or saturation magnetization. Furthermore, the contributions of magnetic and hydrodynamic forces are discussed.

The experimental aspects of such systems are discussed in the presentation 'Observation of the Interaction of Magnetic Particles in a Rotational Magnetic Field'.