Mixing enhancement of novel passive microfluidic mixers with cylindrical grooves

• Published in: Chemical engineering science Vol. 81; pp. 157 - 163
• Main Authors: Wang, Lei, Liu, Danqing, Wang, Xuejing, Han, Xiaojun
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 22.10.2012; Elsevier
• Subjects: Applied sciences; Chemical engineering; Cylindrical groove; Design engineering; Exact sciences and technology; Fluid flow; Grooves; Laminar flow; Microfluidics; Mixers; Mixing; Numerical analysis; Passive mixer; PDMS; Serials; Simulation; Cylindrical groove; Mixing; Passive mixer; Numerical analysis; Laminar flow; PDMS; Fluid mechanics; Reynolds number; Mixer; Design; Groove; Numerical simulation; Microfluidics
• ISSN: 0009-2509; 1873-4405
• DOI: 10.1016/j.ces.2012.07.004

The mixing is difficult but fundamentally important in microfluidic systems. Three simple yet novel passive mixers were designed and fabricated with cylindrical grooves adjoining to the main straight channel. A serial of systematic simulations and experiments have been done with the increase of the groove-depth, ranging from 0 to 3/4-cylindrical groove. All results confirmed the improvement of mixing in these mixers in a short distance (<20mm). Over a wide range of Reynolds number (from 0.1 to 100), the ratios of ‘the percentage of mixing (φ)’ of the mixer with 1/4-cylindrical grooves to that with no grooves increase from 1.23 to 5.11. All designs are very easy to fabricate and have great potential to be integrated into a total microfluidic system. ► Three mixers were fabricated by embedding cylindrical grooves into the main channel. ► Simulated and experimental results confirmed the mixing enhancement of the mixers. ► The effect of cylindrical grooves is more pronounced at greater flow rates. ► Our designs can be easily incorporated into a total microfluidic system.