Figure 1.

Particle separation with cross flow filtration and laminar flow. (A) Cross flow filtration. Particles smaller than the micro pores on the side walls are continuously extracted into the side channels. The flow in the main channel perpendicular to the micro pores prevents fouling of larger particles on the pores. (B) Asymmetric pinched flow fractionation. Particles introduced from inlet 1 are hydrodynamically aligned against sidewall 1 of the pinched segment, where the centers of mass of the particles are dictated by the radii. Particles are then separated into different trajectories in the diverging section. Reproduced from Takagi et al., 2005 by permission of The Royal Society of Chemistry. (C) Deterministic lateral displacement. In a laminar flow around staggered arrays of posts, small particles stay within a band stream (between two adjacent dashed lines) and come back to the same lateral position every three rows. Large particles, however, are forced to laterally shift after each row as the center of mass needs to cross the boundary of the two adjacent streams. Adapted from Davis et al., 2006, Copyright 2006 National Academy of Sciences, U.S.A.