CDF Analysis of Particle Magnetophoresis in Multiphase Continuous-Flow Bioseparators

The use of magnetic particles has recently expanded for a process known as detoxification in which different toxins are captured from the bloodstream of septic patients. Due to the laminar flow developed in microfluidic devices, the particle separation after the toxin capture can be carried out in a continuous mode using multiphase microfluidic channels. In this work, the design for a two-phase continuous-flow microseparator and an optimization study for the separation of magnetic beads from blood are presented. The numerical method includes a combination of magnetic and fluidic computational models that were solved using the VOF method with the commercial flow solver FLOW-3D, whereas an external Fortran subroutine was employed for the calculation of the magnetic fields and forces. For optimization purposes, a dimensionless number J is introduced. The results show that complete and safe separation is achieved only for a certain value of J (≈0.3). To the best of our knowledge, this is the first computational study of the interaction between two different fluids flowing simultaneously in the device that takes into account two-way coupled particle-fluid interactions in the flow field and the particle motion effects as they cross the interface between the fluids under various magnetic field intensities.