Trajectory of particles exposed to a tilted-angle washboard potential: application to high-throughput acoustophoresis in microchannels

Wei Wang; Jia Zhou; Antoine Riaud

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arXiv · 1902.08892

Trajectory of particles exposed to a tilted-angle washboard potential: application to high-throughput acoustophoresis in microchannels

Wei Wang·Jia Zhou·Antoine Riaud

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Abstract

A wide variety of tilted washboard potentials based on acoustic waves, electric fields, optical patterns and so on have been applied to sort particles in microchannels. In this paper, we present a theoretical analysis of the particles trajectory in a washboard potential making a tilt angle $\theta$ with the flow. Depending on the sorting to drag force ratio $\epsilon$, we identified a transition threshold $\epsilon = \cos(\theta)$ between two distinct regimes of particles motion: drift and locked modes. In drift mode, the particles follow an oscillating trajectory which slope is given by $\frac{\epsilon^2}{2}\tan(\theta)$, while in locked mode the trajectory slope is given by $1/\tan(\theta)$. These theoretical predictions agree quantitatively well with previously published experimental data and may help in the design of high-performance microfluidic sorting devices.

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Wei Wang, Jia Zhou, Antoine Riaud. 2019-02-24. Trajectory of particles exposed to a tilted-angle washboard potential: application to high-throughput acoustophoresis in microchannels. https://arxiv.org/abs/1902.08892

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