Open Access

ABSTRACT

Chaotic Mixing in a Microfluidic Device

Chih-Chang Chang, Ruey-Jen Yang¹

1 Departmentof Engineering Science, National Cheng Kung University E-mail: rjyang@mail.ncku.edu.tw

The International Conference on Computational & Experimental Engineering and Sciences 2009, 10(2), 77-86. https://doi.org/10.3970/icces.2009.010.077

Abstract

This paper presents a theoretical investigation into chaotic mixing in low Reynolds number electro-osmotic flows. In this mixing system, the primary flow is the plug-like electro-osmotic flow contributed by the permanent surface charge at the wall, and the secondary electro-osmotic flows (or electro-osmotic recirculating rolls) contributed by the field-effect-induced surface charge act as the perturbed flow. By time-periodic switching two different secondary electro-osmotic flows, it makes streamlines to cross at successive intervals and results in chaotic mixing. Dynamic system techniques such as Poincaré map and finite-time Lyapunov exponent analyses are employed to describe the behaviors of particle motion in this mixing system. Finally, the optimum operating condition (e.g. amplitude and time-switching period) for the mixing is identified.

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