Combination of inertial focusing and magnetoporetic separation in a novel microdevice

摘要

Separation of microparticles is of great importance in diagnostic, chemical, and biological analysis, as well as food processing and environmental assessments. In the present work, a novel microfluidic device is designed to focus microparticles based on inertial and magnetophoretic impacts. Three permanent magnets are mounted in the vicinity of the microchannel to separate the diamagnetic particles suspended in a ferrofluid by applying a negative magnetophoretic force. Polystyrene particles with three sizes of 5, 10, and 15 mu m are separated from each other using the proposed device with 100% separation efficiency. The results show that high purity of particle collection can be achieved using Halbach array of magnets at Reynolds numbers of 100 and 110. The influence of inlet flow velocity, magnets' configuration, and their distance from the microchannel is investigated and the optimal situations are determined.