Bioparticle separation in non-Newtonian fluid using pulsed flow in micro-channels

Abstract

Micro total analysis system (lTAS) devices frequently need to deal with bio-particle suspensions in solution and separation of certain bio-particles is often desirable. Separation of plasma from the whole blood has become increasingly popular in clinical diagnostics. Using the coupled volume of fluid (VOF) and the discrete phase (DP) governing equations for multiphase flow, the effect of Newtonian viscosity of water and the non-Newtonian shear-thinning viscosity of blood on particle separation under pulsed pressure condition is determined. It is observed that the red blood cells (RBC) accumulate at the front of the blood column while the opposite is observed in water. For the selected parameters, 20% of the plasma observed is to be separated from the whole blood, while in contrast, for a 98% diluted blood, 45% of the plasma can be separated. The present calculations can be adopted to design the flow parameters necessary for the instantaneous separation of plasma from the whole and the diluted blood for lTAS; thus reducing the number of experimental studies.

Pressure sensor positioning in an electrokinetic microrheometer device: simulations of shear-thinning liquid flows

“…As we are interested here primarily in how the pressure profile changes with different k and n values, we have selected a typical flow profile at k = 3, n = 0.5, which serves to illustrate the features of the flow including the velocity, viscosity, and electric field profiles. These values are within the typical range of those for non-Newtonian flows, e.g., for blood, k = 3.313, n = 0.3568 (Devarakonda et al 2007). The applied electric potential distribution in the T-junction is shown in Fig.…”

“…For example, human blood (Devarakonda et al 2007), mayonnaise, and dilute polyethelene glycol solutions (Guillot et al 2006) and dilute linear polystyrene solutions (Tanner 2002) all satisfy the Carreau model and have viscosity ratios in the region 10 -5 B l à 1 B 10 -2 . The ranges of the Carreau parameters were chosen to include a broad range of fluids.…”

Design Principles for Microfluidic Biomedical Diagnostics in Space

“…3(a) demonstrates the utility of simple bifurcations to extract pure plasma (Yang et al, 2006). Processing time could be reduced by adding pulsatile flow (Devarakonda et al, 2007), but the increased complexity and fouling potential may be of concern for space diagnostics. Another design option is to send the entire fluid stream through a constriction followed by an expansion.…”

Microfluidic high viability neural cell separation using viscoelastically tuned hydrodynamic spreading

“…Viscoelastic is an interesting phenomena existing in fluid due to the elastic component of the liquid and it has also attracts the attention from the microfluidic community (Squires and Quake 2005), e.g. for mixing (Gan et al 2006), focusing (Leshansky et al 2007) and particle fractionation (Devarakonda et al 2007). However, to our understanding this is the first study of viscoelasticity tuning of the hydrodynamic spreading in a microfluidic channel.…”