Title: How Does Rigidity Emerge and Disappear in Soft Matter?

Author (Invited): Xiaoming Mao, University of Michigan

Abstract:

Rigidity is a central theme in soft matter as it controls how materials deform and flow under stress. Due to their complicated, disordered structures, characterizing rigidity of soft materials poses a grand challenge for theory. Classical theories of rigidity percolation and jamming are wonderful examples of understanding rigidity in disordered soft matter. However, new questions arise when we examine rigidity in more varieties of soft matter: Why colloidal gels have rigidity at volume fractions far below classical thresholds for rigidity? When soft materials fail under stress do they behave differently from crystals? We will discuss these questions in this talk, introduce mathematical frameworks for understanding rigidity, and explore scenarios where we can we use what we learn to control how soft matter solidify and flow.