Event Detail Information
"Bringing colloids to life" - Colloids are micron-sized particles widely used in industrial processes and everyday products. Agitated by solvent molecules, colloids constantly move in a Brownian fashion. This is in sharp contrast to bacteria, which use internal fuels to actively move around and exhibit intriguing collective, nonequilibrium patterns. To introduce vitality into colloidal particles, I employed time-dependent magnetic and electric fields, to generate active rotation and translation of individual colloids. The external energy supply leads to a rich variety of novel collective phenomena. In one context, Janus particles self-assemble into dynamic tubular structures in which they dance in a synchronized fashion. In another context, particles spontaneously swarm in a pattern similar to animal herds. The overall goal of this talk will be to demonstrate the excitement, surprises, as well as puzzles arising when active motion is introduced into colloidal particles via external excitations.