(550c) Separation of Binary Rigid and Deformable Particles with Varying Moduli in Microfluidic Flow

In small, confined channels, particles passively drift towards the wall of the channel, a phenomenon known as margination. In pressure driven flow, drift is due to a combination of effects such as hydrodynamic and shear gradient diffusion as well as wall migration.1 The various phenomenon that determine particle migration also occur in multicomponent systems such as blood, where red blood cells will migrate towards the center of the channel while white blood cells, platelets, and foreign drug carriers marginate towards the wall of a blood vessel.2-4 The drift of drug carriers can be controlled by a multitude of particle properties such as size, shape, and deformability. The effect of size and shape are well understood, with a general consensus that larger micron-sized particles marginate more than their nano-sized counterparts, while non-spherical particles marginate more than spherical particles.5 The effect of particle deformability has yet to be fully characterized. With drug carriers being made from a wide variety of materials, it is important to understand how inherent material deformability affects the cross stream migration of a particle. To quantify particle margination, we measure particle position in steady state flow. In this presentation, we first discuss particle displacement measurements of uniform species in parabolic flow, varying the particle moduli for both nano- and micro-sized particles. We then mix deformable particles with rigid spheres to further determine how deformable particles behave in a multicomponent system. In this work, we aim to formulate a quantitative relationship between particle deformability and margination. We hope this work will improve the understanding of the mechanisms driving deformable particle margination. We also hope this work will help to refine drug carrier design.

1. Henriquez Rivera, R. G.; Zhang, X.; Graham, M.D., Mechanistic theory of margination and flow-induced segregation in confined multicomponent suspensions: Simple shear and Poiseuille flows . Physical Review Fluids 2016, 1.

2. Goldsmith, H. L.; Spain, S., Margination of Leukocytes in Blood-Flow through Small Tubes. Microvascular Research 1984, 27 (2), 204-222.
3. Bagge, U.; Karlsson, R., Maintenance of White Blood-Cell Margination at the Passage through Small Venular Junctions. Microvascular Research 1980, 20 (1), 92-95.
4. Tangelder, G. J.; Teirlinck, H. C.; Slaaf, D. W.; Reneman, R. S., Distribution of Blood-Platelets Flowing in Arterioles. Am J Physiol 1985, 248 (3), H318-H323.
5. Sen Gupta, A., Role of particle size, shape, and stiffness in design of intravascular drug delivery systems: Insights from computations, experiments, and nature. Wiley Interdisciplinary Reviews: Nanomedicine and Nanobiotechnology 2016, 8 (2), 255-270.