Numerical Study on Delivery of Micro Particles Hydrodynamically Focused in Micro Channels

Observing phytoplankton can help understand the carbon and nutrient fluxes in marine ecosystems and is an important indicator of how human activities affect coastal marine ecosystems. However, most of the phytoplankton have complex, irregular appearance, internal structure, organic or chemical composition and biological activity, which makes it difficult to detect. Recent years, the rapid development of automatic image systems based on high precision cameras has made it possible to study plankton on fine temporal and spatial scales. In this paper, We focus on the different sample paths and velocities, especially the micro particles of around 20μm, under the change of ratio of sample flow and sheath flow rate, and will theoretically analyze the hydrodynamic focusing process of micro particles in the square channel, and simulating the movement of the sample particles in sheath flow by computational fluid dynamics method to find an appropriate combination of the sheath flow and sample flow for hydro dynamically focusing.