Hydrodynamic lift forces on solutes in a tilted nanopillar array: A computer simulation study

Abstract

We study solute transport in a microfluidic channel, where the walls hold an array of tilted rigid nanopillars. By solving numerically the flow equations in the channel, we show that a combination of hydrodynamic effects with excluded volume interactions between the solute particles and the pillars leads to a hydrodynamic lift effect, which varies with the particle size, and depends in a strongly nonlinear fashion on the flow rate. We show that the lift force can be sufficiently strong to drive the solute accumulation or removal from the pillar region and can be switched to the opposite direction by variation of the shear rate or driving pressure. We also demonstrate that the nanopillar array can be used to selectively attract particles of certain size and enhance solute trapping at the surface.

Endothelial Glycocalyx Permeability for Nanoscale Solutes

“…Therefore, one can assume that the overall permeability should decrease in the presence of the flow. Second, lift forces might appear inside the layer if the flow velocity is high enough inside the EG [40]. Such lift forces in theory may have an impact on the distribution of NPs in the regions close to the interface between the bulk solvent and the polymer chains.…”

“…The NP density as a function of height over the cell membrane samples the distribution of space inside the EG, which can transport the solutes toward the membrane. This method does not include any possible hydrodynamic lift forces [40]. In order to estimate the lift forces and the difference in EG permeability caused by their presence, we also performed simulations with the original MD-lattice Boltzmann setting and found that the size of the effect was negligible.…”

Recent progress on microfluidic devices with incorporated 1D nanostructures for enhanced extracellular vesicle (EV) separation

“…Recently, significant progress has been made on microfluidic-based EV isolation approaches, which offer improved separation efficiency, reduced processing time, and the ability to meet sample volume requirements [29,30]. Previously, the laminar and uniaxial flow in conventional planar substrate-based microfluidic devices commonly resulted in limited interaction between the particles and the device surface [31,32]. Today, non-planar microfluidic devices with incorporated nanostructure substrates have been developed and exhibit promising EV capture performance.…”