Microfluidics is a multidisciplinary field which finds various applications and contributes profoundly to healthcare, diagnostics and lab-on-chip applications. Microfluidic devices and chips mostly employ micromixers. The main purpose of microfluidic mixing is to achieve a full, complete and rapid mixing of several samples in the microchannels of microfluidic devices. In such devices, sample mixing is fundamentally accomplished by proper designing of the microchannels. In active micromixers, there is an application of external energy force to disturb the sample species. In passive micromixers, the contact area of the fluid samples is increased by changing the structures of the microchannels. Many mixers have been suggested to facilitate mixing. In this paper, we see an overview of passive microfluidic mixing devices and then the performance of different designs of micromixers are compared based on the concentration at the outlets. The micromixer design and simulations have been carried out using COMSOL Multiphysics® software. Simulations are implemented using flow rates of 1nL/min and 1µL/min with different diffusivities. The microfluidic channels have been fabricated and the simulation results have been verified experimentally. The results obtained can be used for design of efficient micromixer for integration with micro total analysis systems, lab-on-chip and healthcare applications

Microfluidics; Micromixers; Microchannel; Passive micromixer; Mixing