Summarized effects of particle size, shape, and deformability on inertial focusing equilibrium behaviors. (a) Images of particles of different sizes equilibrating at different distances from a wall, with plots of these positions and associated rotation rates of spherical particles (38). (b, left) Photolithographic images of particles of different shapes focusing in a straight channel. (Reprinted with permission from Reference 74. Copyright 2011, AIP Publishing LLC.) (right) Oblong particles—made by melting and stretching spherical particles—focusing in a straight channel (75). (c) Droplets of different ratios of internal to surrounding fluid viscosity demonstrating the effect of deformability on inertial focusing in a straight channel. (Panel reproduced from 76 with permission from The Royal Society of Chemistry.) Abbreviations: FSG, shear gradient lift force; FWI, wall interaction force; ω, angular velocity; UP, particle velocity.