Effect of channel height on the critical particle diameter in a deterministic lateral device

Abstract

The separation of biological cells or microorganisms in a liquid based on their size by deterministic lateral displacement is widely used in laboratories. The analytical equation for the critical diameter is derived under the assumption that flow between two posts is better described by flow in a rectangular tube than between parallel plates. The height position of the particle is an additional parameter that affects the critical diameter. Preliminary experiments were carried out on the separation of particles in deep and shallow microchannels. This study shows that the critical diameter is not a constant value for a given design but is different on each plane parallel to the top and bottom of the channel. The theoretical model was used to analyze experimental data on the separation of particles larger than 4.2 µm from particles ranging in size from 2.5 to 7.9 µm.