A novel passive micromixer: lamination in a planar channel system

A novel passive micromixer concept is presented. The working principle is to make a controlled 90° rotation of a flow cross-section followed by a split into several channels; the flow in each of these channels is rotated a further 90° before a recombination doubles the interfacial area between the two fluids. This process is repeated until achieving the desired degree of mixing. The rotation of the flow field is obtained by patterning the channel bed with grooves. The effect of the mixers has been studied using computational fluid mechanics and prototypes have been micromilled in poly(methyl methacrylate). Confocal microscopy has been used to study the mixing. Several micromixers working on the principle of lamination have been reported in recent years. However, they require three-dimensional channel designs which can be complicated to manufacture. The main advantage with the present design is that it is relatively easy to produce using standard microfabrication techniques while at the same time obtaining good lamination between two fluids.