Host: Leo Radzihovsky. Coffee, tea and cookies will be available before regular colloquia beginning at 3:45 p.m. in DUAN G1B31.
Collections of self-propelled entities, from living cells to engineered microswimmers, organize in a rich variety of active fluid and solid states, with unusual properties. For instance, active fluids can flow with no externally applied driving forces and active gases do not fill their container. In this talk I will describe the behavior of such “active materials” and highlight two examples of active phase transitions. The first is the formation of cohesive matter with no cohesive forces in collections of purely repulsive active colloids. The second is a model of epithelial tissues that exhibit a liquid-solid transition at constant density driven by cell motility, contractility, and cell-cell adhesion.