Development of a hybrid acousto-inertial microfluidic platform for the separation of CTCs from neutrophil

Abstract

The ability to fast and precise cell separation is a crucial issue for many biomedical applications and diagnoses. Despite several active and passive cell separation methods, high throughput, biocompatible, and label-free techniques are still demanding. High-accuracy acoustic and high-throughput inertial microfluidics can be integrated by combining acoustic and inertial methods. Accordingly, a new solver and two libraries have been developed in OpenFOAM to simulate particle tracking in a two-stage microchannel for focusing and separating particles simultaneously. In the first stage, the different Aspect Ratios (AR) of a serpentine microchannel with four different configurations were simulated in a range of flow rates to achieve the proper particle focusing. The results showed that the square serpentine configuration with AR=0.2 and flow rate of Q=2 ml/min gives a more favorable particle focusing. This channel was then linked to the second-staged straight channel for acoustic separation of breast cancer cells (MCF-7) and neutrophil white blood cells (WBCs). The separation was also compared for standing and traveling surface acoustic waves over a voltage range, and efficiency and purity were obtained for each outlet. At a flow rate of 2 ml/min, which is about four folds higher than the literature, the separation efficiency for MCF-7 cells was 99.3%, and the purity was 93.5% using standing surface acoustic waves (SSAWs). This high-throughput and high-accuracy proposed microfluidic device promises to be used for Lab-on-Chip (LOC) clinical applications for rapid and early detection before cancer metastasis.