(138d) Controlling Dynamic Structures in Linked Colloidal Particle Chains

Semi-flexible filaments in fluid environments move and deform in response to external forces, leading to a rich variety of non-reciprocal orbits, which have significant potential for application in microfluidic scale propulsion and fluid manipulation. In order to harness these phenomena, we must understand the competition of various elastic, hydrodynamic, and external forces on the filament, particularly in the semi-flexible regime. Using a tunable, colloidal particle chain system, driven by an external, rotating magnetic field, we are able to experimentally probe various dynamics. Multiple dynamical regimes are observed, and we focus in particular on two regimes where chains can beat with a periodic deformation, or coil entirely. By pairing these experiments with Brownian dynamics simulations, we elucidate, predict, and begin to optimize semi-flexible fiber behavior as a function of the dimensionless Mason and magnetoelastic numbers of the system.