Particle Separation Based on Size in A Spiral Microfluidic Device

Micro and nanoparticle size separation is of great importance in many medical and environmental applications# # in this study, the concentration and separation of micron particles (hundreds of nanometers) with a diameter equivalent to viruses from larger particles with a diameter of white and red blood cells in a spiral microchannel using the viscous drag forces on the particles in these channels in addition to the inertial forces in the direct channels are shown# the magnitude of these two forces depends largely on the size and density of the particle, the fluid velocity, and the radius of curvature of the spiral microchannels# smaller particles are trapped in the dean vortices formed in these channels and concentrate on the outer wall of the microchannel whereas large particles are balanced by the inertia lift force and drag force within the inner wall of the microchannel# based on comsol software simulations, the spiral microchannel 180 μm wide and 60 μm high with the smallest and largest radius of 3#6 mm and 5#03 mm and 5 loops, the distance between two consecutive loops is 0#36 mm, is capable of separating 250 nm particles (diameter equivalent to viruses) from 7 μm and 12 μm (diameter equivalent to red and white blood cells)# to achieve the ideal separation with the lowest possible pressure drop, the optimum speed 84#6 mm s-1 and flow rate of 54#8 ml min-1 was considered#