Simulation and fabrication of a three-dimensional microfluidic mixer in a monolithic glass substrate

We present a three-dimensional (3 D) microfluidic mixer made in a monolithic glass substrate, which comprises a microchannel structure with multiple bends either in plane or out of plane of the substrate and with varying cross-section. The microfabrication of the mixer is achieved using a photosensitive elastomer as mask and powder blasting as the erosion technique for the glass. Numerical simulation by Comsol Multiphysics is used to simulate the fluid flow in the mixer. It is found that the mixing operation is governed by chaotic advection and multiple vortices, as induced by the multiple channel bends and the strongly varying microfluidic cross-section. We demonstrate very efficient and rapid mixing of parallel laminar flow streams that enter the mixer (C) 2015 The Authors. Published by Elsevier Ltd.