Open Space Diffusive Filter for Simultaneous Species Retrieval and Separation.

We present a novel method for the local retrieval of surface bound species and their rapid in-line separation using an open space microfluidic device. Separation can be performed in less than 30 s using the difference in diffusivities within parallel microfluidic flows. As a proof-of-principle, we report the rapid and efficient filtration of polystyrene beads from small molecules and surface bound red blood cells from dimethyl sulfoxide for antigen typing.