title: 3D nanomolding and fluid mixing in micromixers with micro-patterned microchannel walls.
abstract: Microfluidic devices where the microchannel walls were decorated with micro and nanostructures were fabricated using 3D nanomolding. Using 3D molded microfluidic devices with microchannel walls decorated with microscale gratings, the fluid mixing behavior was investigated through experiments and numerical simulation. The use of microscale gratings in the micromixer was predicated by the fact that large obstacles in a microchannel enhances the mixing performance. Slanted ratchet gratings on the channel walls resulted in a helical flow along the microchannel, thus increasing the interfacial area between fluids and cutting down the diffusion length. Increasing the number of walls decorated with continuous ratchet gratings intensified the strength of the helical flow, enhancing mixing further. When ratchet gratings on the surface of the top cover plate were aligned in a direction to break the continuity of gratings from the other three walls, a stack of two helical flows was formed one above each other. This work concludes that the 3D nanomolding process can be a cost-effective tool for scaling-up the fabrication of microfluidic mixers with improved mixing efficiencies.Graphical abstractIn this paper we show that a micromixer with patterned walls can be fabricated using 3D nanomolding and solvent-assisted bonding to manipulate the flow patterns to improve mixing.
authors.affiliation: Mechanical and Industrial Engineering Department and Center for Bio-Modular Multiscale Systems for Precision Medicine, Louisiana State University, Baton Rouge, LA 70803 USA.|School of Engineering, Texas State University, 601 University Drive, San Marcos, TX 78666 USA.
authors.forename: Bahador
authors.initials: B
authors.lastname: Farshchian
authors.affiliation: Mechanical and Industrial Engineering Department and Center for Bio-Modular Multiscale Systems for Precision Medicine, Louisiana State University, Baton Rouge, LA 70803 USA.
authors.forename: Alborz
authors.initials: A
authors.lastname: Amirsadeghi
authors.affiliation: Mechanical and Industrial Engineering Department and Center for Bio-Modular Multiscale Systems for Precision Medicine, Louisiana State University, Baton Rouge, LA 70803 USA.
authors.forename: Junseo
authors.initials: J
authors.lastname: Choi
authors.affiliation: Mechanical and Industrial Engineering Department and Center for Bio-Modular Multiscale Systems for Precision Medicine, Louisiana State University, Baton Rouge, LA 70803 USA.
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Park
authors.affiliation: School of Engineering, Texas State University, 601 University Drive, San Marcos, TX 78666 USA.
authors.forename: Namwon
authors.initials: N
authors.lastname: Kim
authors.affiliation: Mechanical and Industrial Engineering Department and Center for Bio-Modular Multiscale Systems for Precision Medicine, Louisiana State University, Baton Rouge, LA 70803 USA.
authors.forename: Sunggook
authors.initials: S
authors.lastname: Park
keywords: 3D molding; Advection; Flow patterns; Secondary flow; Surface structures in microchannel