Microfluidics: Three Dimensional, Sheathless, and High‐Throughput Microparticle Inertial Focusing Through Geometry‐Induced Secondary Flows (Small 5/2013)

The process of single‐stream microparticle inertial focusing in a single focal plane without sheath fluids and external forces, all in a high‐throughput manner, is described on page 685 by D. Di Carlo and co‐workers. The proposed design consists of a low‐aspect‐ratio straight channel interspersed with a series of constrictions in height arranged orthogonally, making use of two inertial effects: inertial microparticle focusing and geometry‐induced secondary flows. A focusing efficiency as high as 99.77% is demonstrated, with a throughput as high as 36 000 particles s −1 for a variety of different sized particles and cells. Cover illustration by Marc Lim.