Kamyar Maleki Bagherabadi - MSc of Mechanical Engineering, Sharif University of Technology, Kish International Campus
Mahdi Sani - Assistant Professor, Sharif University of Technology, Kish International Campus
Mohammad Said Saidi - Professor of Mechanical Engineering, Sharif University of Technology, School of Mechanical Engineering

Micro-mixers are vital components of Lab-on-a-Chip devices. Increasing the mixing quality and reducing themixing time remains as an open challenge in their design. Inthis work, we study some of the effects of the positioning ofthe electrodes on the enhancement of the mixing efficiencyand reduction of mixing time. To approach the real physicsof electro-osmosis and capture the phenomena at the ACelectrodes, we numerically solve inter-coupled PoissonNernst-Plank–Naiver-Stokes equations (PNP-NSE systemof equations) using an in-house code (Rayan). In contrary toother approximate low-cost models like traditional Poisson-Boltzmann (PB) model, PNP-NSE model can captureelectro-migration and ion convection on charge densityredistribution. For the first time in the open literature, wepresent the installation of the electrodes on the verticalwalls of the mixing chamber. Using this vertically mountedelectrodes we were able to reach to a mixing efficiency of99% without increasing mixing time.

Lab-on-a-chip, Active-Micro-Mixer, Electroosmosis,Poisson-Nernst-Planck-Naiver-Stokes Model(PNP-NSE), Vertically Mounted Mixing Electrodes