Computational Analysis of a Microfluidic Magnetophoretic Device for DNA Isolation

A continuous flow magnetophoretic DNA isolation device was modeled using COMSOL Multiphysics and MATLAB to study and optimize the fluidic flow and geometric parameters of the device. The optimization was performed with the intention of increasing the volumetric flow rate and thus increasing the sample processing capabilities of the device. Key features of the device include oppositely oriented magnets that provide extremely strong magnetic field gradients and improve the capture rate of the magnetic particles. Another feature of the device is a nickel grid arrayed on the bottom surface of the channel to create localized amplified magnetic field gradients, and to provide even spreading and capture of the particles on the bottom surface of the device. These features in conjunction with the optimization of the fluid flow and geometric parameters provide the ability for higher velocity sampling and increased throughput. The simulation was conducted in two steps. First the fluid flow and the magnetic field simulations were performed in COMSOL Multiphysics. Next, the values of velocity fields and magnetic field gradients throughout the computational domain were exported to MATLAB to calculate the motion and trajectory of the particles. The particle trajectory analysis was performed until the particle either reached the bottom of the channel or was not captured within the set length and flowed out to the outlet channel.