ELASTO-INERTIAL FOCUSING AND MIGRATION OF PARTICLES FOR HIGH-THROUGHPUT SEPARATION

In this work, we report particle focusing at dynamic range of flow rates and particle migration and separation using single inlet high aspect ratio straight microchannels.Our experimental work covers a wide range of dimensionless numbers (0.05 < Reynolds number < 85, 1.5 < Weissenberg number < 3800, 5 < Elasticity number < 470) and our results show that particle size plays a dominant role, and by tuning the parameters, particle focusing can be achieved at Reynolds number ranging from 0.2 -85.As a proof of principle, we demonstrate separation of 5 m, 7 m and 10 m particles in a sheath-less flow at a throughput of 150 L/min.The presented work sheds light on the complex particle transport in elasto-inertial flows for applications in high-throughput and high-resolution particle separation.Although there is considerable interest in the field of elasto-inertial microfluidics owing to its potential applications, research on particle focusing has been mostly limited to low Reynolds numbers (Re<1) [1], especially in flow through straight rectangular cross-section channels, and particle migration towards equilibrium positions is not well studied.In addition, the particle separation applications in the previous studies using straight channels all considered two inlets where one inlet carries the sample flow and the second inlet carries a sheath flow [2].The utilization of the sheath flow decreases the overall throughput.To overcome these issues, we present a high aspect ratio (AR, height>width) microfluidic channel with a single inlet, which initially focuses all particles and then separates them by size exploiting the difference in their migration speed.