Frustration and non-equilibrium assembly in soft condensed matter: confined crystals, aging glasses, drying drops, and more

While we would like to avoid frustration in our daily lives, frustration in condensed matter produces novel phenomena with important consequences. Materials that are geometrically frustrated cannot minimize the energy of every particle-particle interaction, even in their ground state; materials that are kinetically frustrated are trapped out of equilibrium, i.e., they cannot reach their ground state. In this talk I will review a series of experiments I have performed investigating the role of frustration in the assembly and phase behavior of colloidal systems. By tuning particle size, shape, and confinement, I systematically varied the degree of frustration in each experiment. This controlled approach enabled me to create geometrically frustrated colloidal "antiferromagnets," to observe the competition between crystallization and vitrification, and to learn how glasses age. These concepts also appeared in other non-equilibrium soft condensed matter experiments, from materials assembled on the surface of drying drops, to the directed assembly of protein-based structures.