Rapid and controllable microfluidic mixing via magnetically functionalized PDMS micropillar arrays

B. Zhou, W. Xu, X. Zhang, W. Wen
Hong Kong University of Science and Technology,
Hong Kong

Keywords: mixing, microfluidics, magnetically functionalized pillar

Summary:

In this study, magnetically functionalized PDMS micropillar arrays were successfully designed, fabricated and implanted in microfluidic channel for rapid and controllable mixing. The arrangement of PDMS micropillar arrays inside the microchannel can be flexibly regulated by an external magnetic field (generated from a permanent magnet). As a consequence, the flow fields inside the microfluidic channel can be regulated at will via the magnetic activation conveniently. When a microchannel is implanted with such micropillar arrays, two microstreams with different concentrations can be mixed easily and controllably upon the simple application of an on/off magnetic signal. Mixing efficiencies based on micropillar arrays with different densities were investigated and compared in this work. Our microfluidic system is capable of generating highly reproducible results within many cycles of mixing/non-mixing conversion. We believe that the simple mixing–triggering method together with rapid and controllable mixing outcome will be extraordinarily valuable for various biological or chemical applications in the future.