We are interested in the mechanics of complex fluids and soft materials, and the interesting dynamical phenomena that they exhibit. Examples of the systems we study are dry granular materials, particle-fluid suspensions, viscoelastic fibers such as hair, and suspensions of bacterial cells. The challenges in understanding these materials are several: their rheology is complex, anisotropic, and often history dependent; they are typically multi-phase mixtures, that are prone to spontaneous segregation and kinematic inhomogeneity; the continuum theories that describe them are far more complex than the Navier-Stokes equations that describe Newtonian fluids such as air and water. We employ a combination of tools in our research, such as experimental rheometry and flow imaging, continuum-mechanical theories, and detailed particle dynamics computations.

We work in the following fields:

Granular Materials

Granular or particulate materials are the second most widely used materials in industry (after water). Examples range from fine grains such as cement and pharmaceutical powders to coarser grains such ores and food grains. Our group focuses on building rheological models and understand kinematics of granular systems that can explain their phenomena. Read More

Particle-Liquid Suspensions

In our group, we study the rheology and dynamics of hard, soft and active particle suspensions via analytical, computational and experimental techniques. We confine ourselves to the viscous dominated regime of Stokes flow (Re << 1). Read More

Soft Solids

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Bacterial Communication

We work on the emergence of collective behavior in bacteria, with Vibrio fischeri as the model system. By making quatitative measurements, we try to understand the effect of chemical signalling and physical crowding on the phenotypes such as luminescence, motility, and biofilm formation. Read More