Rapid laminating mixer using a contraction-expansion array microchannel

Abstract

Three-dimensional lamination mixing is demonstrated in a simple and easily fabricated contraction-expansion array microchannel. The abrupt change of the cross-sectional area of the channel curves fluid streams and accelerates the flow velocity especially at the entrance of the contraction region. Centrifugal effects at that region result in Dean vortices that continuously split and redirect fluid streams, thereby enabling appreciable mixing. The presented mixer provides a level of 90% mixing in the relatively large range of Reynolds number from 4.3 to 28.6 by employing the channel with 30 contraction-expansion units.