Modal Analysis Of Concentration Information In A Magnetic Micromixer

Abstract

Mixing is one of the most frequently used processes in microfluidic devices and Lab-on-a-Chip applications, therefore subtantial flow field investigation efforts are spent to achieve high performance micromixers. In this work, we revisit a magnetic micromixer experiment, where velocity, concentration and interface investigations had been carried out. The magnetic micromixer exploits a phenomenon called magnetic microconvection, which appears on an interface of miscible magnetic and nonmagnetic fluids. Initial qualitative concentration measurements are improved, both in terms of accuracy and resolution. The improvements in the experimental setup, improved microfluidic channel geometry, more accurate syringe pumps and inclusion of a concentration calibration step resulted in an accurate, time resolved and quantitative description of the concentration information for magnetic microconvection. In the current work we perform a modal analysis of the concentration field using Proper Orthogonal Decomposition (POD). The modal information provides crucial details about the mixing process at the interface for the magnetic microconvection phenomenon, giving a way to characterize and improve such mixers.