numerical study on low reynolds mixing oft-shaped micro-mixers with obstacles

micromixers are one of the most crucial components of lab-on-a-chip devices with the intention of mixing and dispersion of reagents like small molecules and particles. the challenge facing micromixers is typically insufficient mixing efficiency in basic designs, which results in longer microchannels. therefore, it is desirable to increase mixing efficiency, in order to decrease mixing length, which enables miniaturization of lab-on-chip devices.  this study investigates two different designs of a passive t-shaped micromixer employing several rectangular obstacles and grooves to monitor mixing efficiency with geometry change, while keeping the reynolds number under 2. the mixing performance of these geometries is studied by numerical study and it was implemented in comsol multiphysics environment. it was clarified that t-shaped micromixer with obstacles and grooved micromixer improved mixing efficiency of the basic design by 37.2% and 43.8%, respectively. also, it was shown that this increase in mixing efficiency was due to the development of transversal component of flow caused by the obstacles and grooves.