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.