Enhancement of passive mixing via arc microchannel with sharp corner structure

Abstract

A novel microfluidic device for efficient passive mixing is reported. A series of sharp corner structures designed on side wall of an arc microchannel was utilized to induce three-dimensional vortices, which strongly stretched and folded the interface and significantly increased the interfacial contact area between different fluids. Additionally, the sharp corner structure induced high radial velocity and reduced the diffusion length because of the restricted effect of the geometrical structure. Eventually, the fluid mixing was significantly enhanced, and a mixing efficiency from ∼87% to 92% was achieved at moderate Reynolds number (Re) from 3.0 to 24.2 (10 to 80 μl min−1). The influence of the sharp corner position on the mixing was also investigated by the experiment and the numerical simulation. With single-layer structure and high mixing efficiency, the present device has great potential in the mixing process in variety of lab-chip applications, such as clinic diagnosis and analytic chemistry.

Microreactor-based micro/nanomaterials: fabrication, advances, and outlook

“…Visualization of the interface formed in the channel between the water stream and the ethanol revealed that mixing is a combination of diffusion and fluid agitation. With the cooperation of Xi'an Jiaotong University (China) and the University of Akron (USA), Huang et al 118 proposed a novel microfluidic device for efficient passive mixing, that is, a series of sharp corner structures designed on the side wall of an arc microchannel, as shown in Fig. 10(b).…”

“…(b) Schematic diagrams of arc microchannels, including simple arc microchannels (channel 1), arc microchannels with sharp corners located on external walls (channel 2) and asymmetrically located on both side walls (channel 3). 118 Copyright 2021 IOP, Publishing Ltd. (c) Staggered herringbone mixer (SHM). 119 Copyright 2002, The American Association for the Advancement of Science.…”

A Novel Approach for Visualizing Mixing Phenomena of Reactive Liquid-Liquid Flows in Milli- and Micro-Channels

“…The fabrication technology for micro channels with optical access is available and well established in the field. Aided by CFD and dye shadowgraphs, the 2D (depth averaged) concentration distribution within micro mixers can be determined (Parsa and Hormozi, 2014;Bazaz et al, 2018;Chen et al, 2018;Mariotti et al, 2018;Mariotti et al, 2019;Huang et al, 2021). Confocal laser-induced fluorescence (LIF) allows even deeper insights into stationary flow systems, yielding 3D concentration fields of micro channels with high spatial resolution (Hoffmann et al, 2006;Tsai and Wu, 2011;Hermann et al, 2018;Frey et al, 2021).…”