Numerical investigation of centrifugal passive mixing in Omega shaped microchannel and comparison with fixed platform

Abstract

The extraction of DNA from isolated cells is crucial for diagnosing and treating various diseases, including cancer, which has become a leading cause of death in recent years. Circulating tumor cells (CTCs) in the blood can be separated from other blood cells, allowing for DNA extraction and analysis for further research. Microfluidic methods are more cost-effective than conventional DNA extraction techniques and have significant potential for high-throughput mixing in lab-on-a-chip (LOC) and lab-on-a-disk (LOD) devices without damaging DNA. Chemical methods for cell lysis, where the mixing of reagents is essential, are particularly efficient on these platforms due to the generation of secondary flows. This is especially true in microchannels with a serpentine design, which enhances mixing quality—a critical parameter for cell lysis efficiency. This study presents and compares the mixing capabilities of the two microchannel platforms (LOC and LOD). Additionally, we introduce a new Omega-shaped serpentine microchannel that combines features of both straight and curved serpentine channels. The mixing quality across all geometries and both platforms has been investigated. Our findings indicate that the centrifugal platform is the most effective for mixing at low inlet velocities. Furthermore, we examine the number of stages in the Omega channel and conclude that 7 Ω stages are sufficient for achieving high mixing quality (∼100 %).