AN INTEGRATED MAGNETIC PLANAR ACTUATOR REDEFINING MULTILEVEL (3D) MICROFLUIDIC STRATEGIES

Super-paramagnetic micro particles (SMPs) are broadly used in medical and biological applications (from cellular to genomic scales), but the handling tools for those particles remain mostly non-integrated. Since a decade, a few solutions for integrated actuation have been proposed and paved the way to the micro-scale control of SMPs. So far, spiral planar coils showed the best compromises between the available magnetic force and the actuator footprint. Albeit the technology to integrate this type of coils with microfluidic structures exists, it is hard to find examples of dual architectures using those two aspects for concrete applications. We therefore developed a SU-8 dry film lamination technique, which can be used with standard micro technology processes. It allows us to manufacture lab on chip integrating miniaturized electromagnets. Using that system, we achieved to separate a solution of SMPs with an 80% efficiency at a 2.5 µL/min flow rate (4.6 mm/s). It is also possible to perform trapping (all the beads stay on the coils) at lower flow rate.