A simple three-dimensional vortex micromixer

We demonstrate rapid homogenous micromixing at low Reynolds numbers in an easily fabricated and geometrically simple three-dimensional polystyrene vortex micromixer. Micromixing is critically important for miniaturized analysis systems. However, rapid and effective mixing at these small scales remains a persistent challenge. We compare our micromixer's performance against a two-dimensional square-wave design by examining its effectiveness in mixing solutions of dissimilar concentration as well as suspension solutions comprised of microparticles. Numerical simulations confirm our experimental observations and provide insights on the self-rotational mixing dynamics achieved with our simple geometry at low Reynolds numbers. This rapid, robust, and easily fabricated micromixer is amenable readily to large scale integration.