Control of Interparticle Spacing Using Structured Microfluidic Channels

We report a technique for controlling interparticle spacing and position for inertially-focused particles at high concentrations using structured microfluidic channels. Particle control in flow holds many applications in the development of more efficient microfluidic platforms such as in particle encapsulation for droplet microfluidics, particle separation techniques, and high-throughput flow cytometry. We have evaluated how channel structures, or localized changes to channel width, affect particle behavior and report the following modes of control: expansion and contraction of interparticle spacing, improved accuracy of focusing, and shift of equilibrium positions towards the channel walls.