Microfluidic mixing under low frequency vibration

Abstract

In the laminar flow regime which characterizes the operation of most microfluidic systems, mixing is governed primarily by molecular diffusion. An increase in the interfacial surface between the fluids contained in the system facilitates the mixing process. This can be obtained by active external perturbation, requiring complex systems and complex operation, or passively by clever design over the geometrical constraints. Here, we describe an active micromixer technique based on the excitation of vortices in proximity to sharp corners of junctions, as a result of simple low frequency vibration of the device. Results showing the working principle in both static and fluid through conditions are presented.