Hybrid Bio-Mag-MEMS combining magnetophoresis and dielectrophoresis

The design of a new hybrid magnetic MEMS for biology (Bio-Mag-MEMS) is presented. It combines magnetophoresis, dielectrophoresis and microfluidics. These phenomena are used to sort magnetically tagged and non-tagged objects. Magnetic objects are trapped by the use of high gradient magnetophoresis. Thanks to dielectrophoresis these objects, once trapped, can be successfully released in a buffer. Efficient sorting is performed in this hybrid Bio-Mag-MEMS by using magnetic beads. A high sorting efficiency is demonstrated. Magnetic, Stokes and dielectrophoretic forces in the microfluidic channel are simulated with both analytical tools and the finite element method (FEM). The trajectories of magnetically tagged objects are simulated. Finally the fabrication and optimization of this device are detailed.