Particles Focusing and Separation by a Novel Inertial Microfluidic Device: Divergent Serpentine Microchannel

Microfluidic experiments have found wide applications in medical sciences and engineering, such as cell separation and focusing. In the present study, focusing and separation of particles with different sizes and densities were investigated by designing inertial microfluidic devices. The microfluidic channel is designed by analyzing the induced forces on the particles. In the designing process, the objective was to focus and separate the particles in the shortest length of the channel with the lowest possible cycles and high efficiency. The simulation is then used for analyzing the two proposed geometries to evaluate their particle separation and focusing ability, named convergent and divergent serpentine microchannels. Another critical issue is the low number of cycles required to complete the particle separation and focusing process in the proposed geometries, which shortens the channel length and improves the detection speed. Eventually, divergent geometry showed an excellent performance compared to the convergent geometry in focusing and separating particles. Also, it was shown that in the divergent geometry, the separation of the particles with bigger sizes (e.g., circulating tumor cells) or higher densities from the particles of smaller sizes (e.g., red blood cells) or lower densities has high efficiency.