Out-of-Equilibrium Crystallization and Reconfigurable Colloidal Assemblies Using Light

Field-driven organization of colloidal particles has received significant attention recently for its promise in realizing programmable and reconfigurable microscopic structures. Our group has developed a facile method of organizing colloidal particles into crystalline and amorphous phases using LED light and gold nanoparticles. I will show how the experimental system allows us to answer fundamental questions on crystallization under nonequilibrium conditions for a wide range of particle diameters, from 0.8 μm to 10 μm. I will also discuss our findings on how to design self-limiting, programmable, and reconfigurable assemblies by applying spatiotemporal modulation of light. Since the assembly mechanism is driven by convection flow and hydrodynamic interactions, it can be applied to both polystyrene spheres and soft thermo-responsive microgels, allowing for the investigation of various responsive assemblies.