Spatial Temporal Anisotropic Transport of the Microalgae Chlorella Vulgaris in the Microfluidic Channel

Abstract

Transport of biomaterials in confined geometry exhibit complex dynamics, both in spatial and temporal scales. In this work, we examined the transport behavior of microalgae Chlorella Vulgaris inside the microfluidic channel under pressure-driven Poiseuille flow environment. The microalgae system is treated as the spherical naturally buoyant particles. The algae particles trajectories are visually traced using particle imaging techniques and the sample paths are resolved in stream wise (flow) and perpendicular directions. In order to understand boundary wall effects on the flow, we partitioned the microfluidic channel into three different regions, namely the center region and two near-wall boundary regions based on the velocity flow profile. Time-averaged mean square displacement (MSD), probability density function (PDF), skewness, and kurtosis of finite ensembles of particle trajectories are determined for these regions. In addition to the spatial dependencies, we also examined the transient characteristics of the algae transport at early-time and long-time. We found the existence of the mixed types for transport dynamics irrespective of flow region separation often assumed in many laminar flow simulations. This finding will be useful for optimization of mixing of algae culture in micro-scale photobiore actor as the productivity of cell growth depends critically on the cell dispersion or transport