Soft Materials in Complex Environments: from Porous Rocks to the Human Body
Tremendous progress has been made in understanding the bulk behavior of soft materials. However, diverse applications rely on how these materials behave in complex environments—where environmental factors alter material microstructure, the material itself alters the environment, and these dynamical processes give rise to emergent effects. These coupled interactions pose new challenges to our understanding. In this talk, I will describe two examples, in two very different settings, of how we disentangle the interactions between soft materials and their environments. First, I will describe how we visualize single-phase and multi-phase flow within a disordered 3D porous medium, over length scales ranging from smaller than a pore to that of the entire medium. This enables us to elucidate the physical origin of fluctuations and fluid instabilities in this complex system. Second, I will describe how we combine biological imaging and thermodynamic modeling to probe the mucus hydrogel that lines and protects the gut. We find that this biological barrier responds dynamically to polymers in its environment; moreover, this behavior can be modulated by microbes, revealing an unexpected interplay between polymer content, microbiota, and the biological structures that protect us. Ultimately, this research stimulates new findings and questions at the interface of Engineering, Physics, Materials Science, and Biology.