Axial dispersion of Brownian colloids in microfluidic channels

Inertial and viscoelastic forces on rigid colloids in microfluidic channels.

We perform hybrid molecular dynamics simulations to study the flow behavior of rigid colloids dispersed in a dilute polymer solution. The underlying Newtonian solvent and the ensuing hydrodynamic interactions are incorporated through multiparticle collision dynamics, while the constituent polymers are modeled as bead-spring chains, maintaining a description consistent with the colloidal nature ...

Band Dispersion in Serpentine Channels of Microfluidic Electrokinetic Separation Systems

Dispersion Modeling in Microfluidic Channels for System-level Optimization

Chip-based microfluidic separation systems often use serpentine channels to achieve long separation lengths in minimal area. Such designs suffer from the ‘racetrack’ effect due to the bends in the microchannel. In addition, the skew produced by a bend cannot be undone by an equal and opposite bend due to non-axial diffusion occurring in the inter-turn straight channel. This paper analyzes the n...

Solute Dispersion by Electroosmotic Flow in Nonuniform Microfluidic Channels

Introduction Dispersion is a phenomenon that determines the resolution of several types of liquid phase chromatography, and is an important component of overall transport through electrokinetic flow systems. The severe dispersion of solute as it travels through a U-turn, for example, has attracted recent attention for this reason [1]. In “ideal” electroosmotic flow through uniform, straight cha...

Expansion channels for low-pass filtering of axial concentration gradients in microfluidic systems.

Chemical gradients that run axially in a microfluidic channel often contain undesirable high-frequency concentration variations, or noise, that results from mechanical and thermal fluctuations in the system. In this paper, we describe a passive microfluidic component called an 'expansion channel' (EC), that removes high frequency noise through axial dispersion. We show that the behavior of the ...