A design principle for improved 3D AC electro-osmotic pumps

TL;DR

This paper proposes a new design principle for 3D AC electro-osmotic pumps that enhances flow rates by modifying boundary conditions with non-polarizable materials, rather than changing geometry.

Contribution

It introduces a novel approach to improve 3D ACEO pump performance by altering boundary conditions to amplify flow, surpassing previous geometric optimization methods.

Findings

Flow rates can be doubled with boundary condition modifications.

Non-polarizable materials eliminate opposing flows on vertical surfaces.

Enhanced slip velocities increase overall pump efficiency.

Abstract

Three-dimensional (3D) AC electro-osmotic (ACEO) pumps have recently been developed that are much faster and more robust than previous planar designs. The basic idea is to create a ``fluid conveyor belt'' by placing opposing ACEO slip velocities at different heights. Current designs involve electrodes with electroplated steps, whose heights have been optimized in simulations and experiments. Here, we consider changing the boundary conditions--rather than the geometry--and predict that flow rates can be further doubled by fabricating 3D features with non-polarizable materials. This amplifies the fluid conveyor belt by removing opposing flows on the vertical surfaces, and it increases the slip velocities which drive the flow.