  In the field of biomedicine magnetic beads are used for drug delivery and to
treat hyperthermia. Here we propose to use self-organized bead structures to
isolate circulating tumor cells using lab-on-chip technologies. Typically blood
flows past microposts functionalized with antibodies for circulating tumor
cells. Creating these microposts with interacting magnetic beads makes it
possible to tune the geometry in size, position and shape. We develop a
simulation tool that combines micromagnetics, discrete particle dynamics and
fluid dynamics, in order to design micropost arrays made of interacting beads.
For the simulation of blood flow we use the Lattice-Boltzmann method with
immersed elastic blood cell models. Parallelization distributes large fluid and
particle dynamic simulations over available resources to reduce overall
calculation time.
