Three-Dimensional Multihelical Microfluidic Mixers for Rapid Mixing of Liquids

• Published in: Langmuir 2008-03, Vol.24 (5), p.2248-2251
• Main Authors: Verma, Mohan K. S, Ganneboyina, Sambasiva Rao, Rakshith, Ghatak, Animangsu
• Format: Article
• Language: English
• Subjects: Chemistry; Colloidal state and disperse state; Equipment Design; Exact sciences and technology; General and physical chemistry; Microfluidics - instrumentation; Microfluidics - methods; Surface physical chemistry
• ISSN: 0743-7463; 1520-5827
• DOI: 10.1021/la702895w

Rapid mixing of liquids is important for most microfluidic applications. However, mixing is slow in conventional micromixers, because, in the absence of turbulence, mixing here occurs by molecular diffusion. Recent experiments show that mixing can be enhanced by generating transient flow resulting in chaotic advection. While these are planar microchannels, here we show that three-dimensional orientations of fluidic vessels and channels can enhance significantly mixing of liquids. In particular, we present a novel, multihelical microchannel system built in soft gels, for which the helix angle, helix radius, axial length, and even the asymmetry of the channel cross section are easily tailored to achieve the desired mixing. Mixing efficiency increases with helix angle and asymmetry of channel cross section, which leads to orders of magnitude reduction in mixing length over conventional mixers. This new scheme of generating 3D microchannels will help in miniaturization of devices, process intensification, and generation of multifunctional process units for microfluidic applications.