Mixing Optimization in Grooved Serpentine Microchannels

Abstract

Computational fluid dynamics modeling at Reynolds numbers ranging from 10 to 100 was used to characterize the performance of a new type of micromixer employing a serpentine channel with a grooved surface. The new topology exploits the overlap between the typical Dean flows present in curved channels due to the centrifugal forces experienced by the fluids, and the helical flows induced by slanted groove-ridge patterns with respect to the direction of the flow. The resulting flows are complex, with multiple vortices and saddle points, leading to enhanced mixing across the section of the channel. The optimization of the mixers with respect to the inner radius of curvature (Rin) of the serpentine channel identifies the designs in which the mixing index quality is both high (M > 0.95) and independent of the Reynolds number across all the values investigated.

Fundamental Studies of Rapidly Fabricated On-Chip Passive Micromixer for Modular Microfluidics

“…The results of the present study are very promising when compared to other related studies using complex on-chip structures for mixing procedures [ 15 , 23 , 24 , 25 , 26 , 27 , 28 , 29 ]. In some of these studies, external microelectrodes were used and integrated on the chip to generate frequency switching transverse EOF for chaotic mixing [ 15 , 24 ].…”

“…Other studies developed complex on-chip structures of T-, Zigzag, and Serpentine types [ 25 , 26 ]. Finally, some only presented the model design of the micromixer and showed the simulation results [ 27 , 28 , 29 ]. We intend to continue to study application of the described technique and fabrication method; the sequential mixing of nanoliter fluids is especially useful for processing biomedical samples with only nanoliter volumes using a microfluidic chip platform.…”

Fused Filament Fabrication (FFF) for Manufacturing of Microfluidic Micromixers: An Experimental Study on the Effect of Process Variables in Printed Microfluidic Micromixers

“…Thanks to the popularity of surface patterning in the creation of passive micromixers, FFF can be a simple and effective way to fabricate micromixers. Several studies have demonstrated the effect of patterned grooves or ridges on fluidic behavior in microchannels [ 34 , 35 , 36 , 37 , 38 , 39 , 40 ]. Stroock et al [ 34 ] developed one of the first passive micromixers by placing two different groove patterns and showed that mixing could be enhanced in a staggered herringbone mixer (SHM) at a Reynolds number from 1 to 100.…”

“…Johnson et al [ 36 ] developed a slanted groove mixer (SGM) using an excimer laser system to create a series of slanted wells on the microchannel floor to achieve quick mixing by introducing transverse transportation of the fluids. Many other different types of patterned grooves similar to those by Johnson et al and Stroock et al have been studied to show the effects of various micro and macro ridges or grooves on mixing enhancement in microfluidic devices [ 38 , 40 , 41 ]. Yun et al [ 42 ] investigated the geometric effects of fabricated grooves using laser cutting and milling machines on the cross-movement of dye solutions.…”

Surface Response Based Modeling of Liposome Characteristics in a Periodic Disturbance Mixer

“…However, these methods have shown limitations such as low final lipid concentration [16,18] and relatively poor device reliability [19]. Alternatives to such types of devices are Dean forces-based micromixers, which use curvilinear paths to induce centripetal forces, thus speeding up the mixing process [20][21][22]. Multiple micromixer designs using Dean forces have been previously proposed [19,[23][24][25][26][27], showing promising results for lipid-based nanoparticles both in terms of increased yield (by reducing the Flow Rate Ratio (FRR) required to produce nanosized particles) as well as ease of fabrication of the microfluidic devices.…”