We work in collaboration with the Procter & Gamble Company to understand the flow and breakup of complex fluids.  In particular, we study the pinch-off dynamics of fluids (e.g. lyotropic surfactants and thermotropic liquid crystals) possessing liquid crystalline order. 

Why do some materials grow near-perfect crystals with mirror-smooth faces whereas others grow rough, bumpy crystals? Our group has recently gotten a glimpse of crystal growth in real time — not by watching individual atoms, but rather by freezing model atoms that can be observed directly with an optical microscope.

Colloidal suspensions – where micro-size or nano-size particles are suspended in a fluid – exhibit various equilibrium structures ranging from face-centered and cubic-centered crystals to binary ionic crystals, and even kagome lattices. When driven out-of-equilibrium by shear, even more diverse colloidal structures can be accessed. These structures lead to unique flow behaviors of suspensions.

Articular cartilage, the soft connective tissue that coats bones in joints, is a highly complex and inhomogeneous material. It is made up of a fluid-saturated, cross-linked network of collagen fibrils whose orientation and porosity vary with depth from the articular surface. Interspersed among the network are cells and highly charged molecules called proteoglycans. Cell shape, cell density and proteoglycan density are all also spatially dependent.