Multi-objective optimization of split and recombine micromixer using grey relational analysis method

PurposeThe effective, efficient and optimal design of micromixer is the need in the field of biochemical and biomedical diagnostic systems.Design/methodology/approachIn this paper, multi-objective optimization of split and recombine micromixer (SRM) with different geometrical configurations is carried out. The finite element method-based three-dimensional models are prepared and analyzed using COMSOL Multiphysics 5.0 Software. Taguchi’s design of experiment (DoE), main effect plot analysis, ANOVA and grey relational analysis (GRA) method are used to find out optimum condition. The five geometrical parameters with three levels, namely, angle between inlets, pillar size, pillar shape, aspect ratio and constriction height of SRM are considered as design variables. The mixing index (MXI) and pressure drop (∆P) are considered objective functions.FindingsThe MXI is significantly influenced by pillar shape and aspect ratio, whereas the pressure drop (∆P) by constriction height. Maximum MXI (0.97) with minimum pressure drop (64,587 Pa) is the optimal conditions and obtained at 180 deg angle between inlets, 50 µm of pillar size, 1.5 of aspect ratio, 100 µm of constriction height and ellipse shape pillar cross-section, respectively.Research limitations/implicationsThis optimized SRM can be combined with lab-on-a-chip for biochemical and biomedical analysis.Originality/valueThis work is useful to obtain optimal geometry of SRM for getting efficient performance of micromixer.