Three Dimensional, Sheathless, and High‐Throughput Microparticle Inertial Focusing Through Geometry‐Induced Secondary Flows

A novel inertial focusing platform creates a single-stream microparticle train in a single-focal plane without sheath fluids and external forces, all in a high-throughput manner. The proposed design consists of a low-aspect-ratio straight channel interspersed with a series of constrictions in height arranged orthogonally, making use of inertial focusing and geometry-induced secondary flows. Focusing efficiency as high as 99.77% is demonstrated with throughput as high as 36 000 particles s(-1) for a variety of different sized particles and cells.