Analysis on micro-mixing enhancement through a constriction under time periodic electroosmotic flow

Abstract

Numerical analyses of the recently proposed micro mixer based on periodic electroosmotic flow through a constriction were conducted. The validity and accuracy of the numerical model developed were verified experimentally. The model allows the prediction of operating parameters such as alternating current (AC) amplitude and frequency for optimum mixing. For accurate simulations of flow behavior such that optimum operating conditions could be determined, the electromigration effect of charged fluorescent dye added to the fluid stream must be considered. This effect, which is generally ignored, can be incorporated in the convection diffusion equation. Important factors that govern the mixing efficiency of the mixer, such as the contact area between the two fluids and the amplitude of fluid interface oscillation were quantified based on experimental and numerical results. Detailed error analyses were performed to investigate the sensitivity of simulation results to the variability of constriction width, diffusion coefficient, and fluorescein ion mobility. This also provides an understanding on the fabrication requirement for efficient mixing.

An active microfluidic mixer utilizing a hybrid gradient magnetic field

“…Lots of micromixers based on different working principles have been proposed and can be generally categorized into two types: 1) passive micromixers by the use of specially designed microchannel configurations [10][11][12], 2) active micromixers by the use of external energies (such as mechanical stirrer [13], thermal [14,15], pressure [16,17], and electrokinetics [18][19][20] acting on the fluids. Compared to the active mixers, the passive mixers are simply easier to integrate in microfluidic systems and there are no problems of power consumptions in active mixers such as high temperature due to the Joule heating and high electrical potentials generated by electrodes.…”

Mixing Enhancement of Electroosmotic Flow in Microchannels under DC and AC Electric Field

“…The flow is essentially laminar and hence efficient turbulent mixing is absent (Ansari et al, 2012;Lee et al, 2016). Therefore, the mixing of two different solutions within a microchannel is achieved only by diffusion mechanisms and it will take a very long time (Lim and Lam, 2012). Many microfluidic devices attempt to overcome this disadvantage by passive method or active method (Shamloo et al, 2017;Matías et al, 2018).…”

Tuning the dispersion of reactive solute by steady and oscillatory electroosmotic–Poiseuille flows in polyelectrolyte-grafted micro/nanotubes

“…2013; Hoshyargar et al. 2018) and the intensification of mixing processes using alternating current (AC) electrokinetic pumps (Lim, Lam & Yang 2010; Lim & Lam 2012; Alipanah & Ramiar 2017).…”