Design and Simulation of Microfluidic Passive Mixer with Geometric Variation

Microfluidic designs are advantageous and are extensively used in number of fields related to biomedical and biochemical engineering. The objective of this paper is to perform numerical simulations to optimize the design of microfluidic mixers in order to achieve optimum mixing. In the present study, fluid mixing in different type of micro channels has been investigated. Numerical simulations are performed in order to understand the effect of channel geometry parameters on mixing performance. A two dimensional “T shaped” passive microfluidic mixer is restructured by employing the rectangular shaped obstacles in the channel to improve the mixing performance. The impact of proper placement of obstacles in the channel is demonstrated by applying the leakage concept. It has been observed that, the channel design with non-leaky obstacles (i.e. without leaky barriers) has presented better mixing performance in contrast to channel design with leaky obstacles (i.e. leaky barriers) and channel design without obstacles. The mixing occurs by virtue of secondary flow and generation of vortices due to curling of fluids in the channel on account of the presence of obstacles. This passive mixer has achieved complete mixing of fluids in few seconds or some milliseconds, which is certainly acceptable to utilize in biological applications such as cell dynamics, drug screening, toxicological screening and others.