2025 AIChE Annual Meeting

Kinematics and Navigation of Active Granular Media

Granular media exhibits complex behaviors, where the particles can often behave as both solids and fluids. This project explores the motion of magnetically-responsive microrollers of 44 micron PMMA particles that are half-coated with 100 nm of iron oxide. After fabrication, the particles respond to oscillating magnetic fields and are capable of directed flow through complex geometries, such as mazes and spirals. Our experiments demonstrate how microrollers self-organize into dynamic patterns, are guided toward the center of the magnetic field, and exhibit well-defined fronts of transport. The results provide new insights into active particle systems and can further be applied to drug-delivery systems and microscale transport.