Numerical and experimental study of the baffle-based split and recombine chamber (B-SARC) micromixers

Abstract Microfluidic technology has garnered growing interest in diverse domains. The efficacy and precision of microfluidic devices are significantly influenced by micromixing processes. Micromixers, comprising microchannels designed to blend fluids within a confined space and limited flow pathway, constitute indispensable components of microfluidic systems. Among these components, the micromixer stands out as a critical element, tasked with achieving maximal mixing efficiency while imposing minimal pressure drop. This paper focusses on the numerical and experimental study the baffle-based split and recombine chamber (B-SARC) micromixers. The models of a curved wavy micromixer (without baffle) and the baffle-based split and recombine chamber (B-SARC) micromixers with three baffles such as square, triangular and teardrop shaped baffles been developed using COMSOL Multiphysics software. The mixing performance analysis has been carried out by studying the mixing index and pressure drop. The influence of baffle shapes i.e. square, triangular and teardrop shaped baffles of aspect ratio 1, 1.5 and 2 on mixing performance analysis has been investigated numerically, for widespread assortment of Reynolds numbers (Re) lies between 0.1 and 90. The polydimethylsiloxane (PDMS) baffle-based split and recombine chamber (B-SARC) micromixers have been fabricated. Further, the experimental analysis has been carried out. The experimental analysis for pressure drop as well as mixing index has been performed. A good agreement has been observed between experimental and computational results which leads to validation of the computational results. The results revel the role of diffusion at lower Reynolds numbers and the production of derivative flows owing to advection at higher Reynolds numbers within the considered range of Re.