Designing microfluidic channel that separates elastic particles upon stiffness

Using three-dimensional computer simulations, we model the movement of soft, elastic particles in microfluidic channels with periodic constrictions formed by diagonal solid ridges. Our simulations reveal that when the gap between ridges is smaller than the particle diameter, particles with dissimilar compliance follow distinct paths and segregate to opposite sides of the microchannel. This simple microfluidic method can be useful for continuous stiffness-based sorting and separation of biological cells and synthetic microcapsules.