Numerical investigation of sheathless inertial particle migration and separation approach with a microstructure-patterned channel

Abstract

Microstructure-patterned channels based on sheathless inertial microfluidics have emerged as promising platforms for the migration and separation of multi-size particle mixtures, which is critical for point-of-care testing in the biomedical and environmental fields. This work proposes a quantitative strategy for multi-size particle migration and separation using the microstructure-patterned microchannel. First, we developed a design pattern of the lateral microstructures within a reverse wavy microchannel that enhanced the Dean drag force and inertial lift force. The number of lateral microstructures had a significant impact on the migration positions of small particles where the Dean drag force exceeded the inertial lift force. Next, the mechanism of single-size particle migration positions and multiple-size particle separation dynamics dominated by the enhanced Dean drag force was explored. Moreover, the coupled effects of flow rate, particle size and design pattern within microstructure-patterned microchannels were investigated. The optimal design pattern for the migration and separation of multi-size particle mixtures varied depending on the flow rate. Furthermore, a quantitative strategy was identified and verified for customizing the multi-size migration and separation using a novel explicit scaling factor. This study provides a tuning mechanism and customization strategy for the migration and separation of targeted particles in microstructure-patterned microchannels, which has great potential for practical application in the field of inertial microfluidics.