Magnetic microbeads trapping using microfluidic and permanent magnet system

Abstract

In Lab-on-Chip (LoC) magnetic system, magnetic microbeads are used in selective binding and separation of targeted biological cells under influence of a magnetic field. Enhancing magnetic trapping efficiency is vital for further biological analyses. In this study, trapping efficiency of 4.5 μm diameter magnetic microbeads under permanent magnet configurations and varying microfluidic flow rates has been investigated. In the experimental studies conducted, neodymium iron boron (NdFeB) permanents magnets and polydimethylsiloxane microfluidics with trapping chamber design were used as a LoC magnetic system. At 5 μl/min microfluidics flow, trapping efficiency of single magnet configuration was 92.06 %. Improved trapping efficiency of 95.24 % was observed with double magnet configuration. On the other hand, the trapping efficiency at greater microfluidics flow rate of 20 μl/min were only 20.63 % and 15.87 % for single and double magnet configuration respectively. Trapping efficiency is greater for double permanent magnets configuration and at the slowest microfluidics flow rate.