Study of magnetic microspheres screening in microfluidic chip based on co-simulation method

Magnetic microspheres have been widely applied in DNA determination, bacterial analysis, and information coding. Magnetic microspheres screening is important, as the sizes of the obtained microspheres vary with different manufacturing methods, causing considerable impact on subsequent applications. In this paper, a co-simulation method based on MATLAB and COMSOL was presented to design the magnetic microfluidic chip, which was utilized to separate the magnetic micro-spheres of different sizes efficiently. In order to complete the separation and screening of magnetic microspheres in the microchannel, a movable permanent magnet device was adopted to adjust the magnetic interactions in the separation area, allowing the microspheres to deviate from different distances. A batch analysis of chip model was performed with this method, and an optimal design that showed high efficiency in separating microspheres of different sizes and magnetic properties was also revealed. Moreover, detailed analysis focused on the influence of flow rate, magnetism and arrangement of magnets on the separation effect of the chip. The presented simulation method will not only shorten the chip design time but also have a better understanding of the factors that can affect the separation of particles. This study has shown its potential in the computer-aided design of microfluidic chips for magnetic microspheres screening.