We study how matter moves, organizes, and remembers in complex environments.

From microbes navigating soil to water freezing through permafrost, motion in complex environments is rarely governed by flow alone. Transport and mechanical response are shaped by disorder, confinement, gradients, moving boundaries, and feedback. Chemical gradients redirect particles and microbes, freezing fronts reorganize soft materials, and flows reshape the networks that carry them, leaving a memory of their history. Combining microfluidic and tabletop experiments, numerical simulations, and theory, we connect microscopic mechanisms with macroscopic transport and collective dynamics.

Chemical-gradient transport in complex media: A concentration gradient, set up by a little dissolved salt, sugar, or CO₂, can carry colloids and drug-laden particles through a material with no flow at all. We investigate how diffusiophoresis and diffusioosmotic flows move colloids relative to the surrounding fluid, and how chemotaxis guides bacteria through transient chemical landscapes. We ask how flow, disorder, and confinement shape the resulting dispersion, retention, and delivery in porous media, governing how contaminants are flushed from soil, how drugs reach tissues and biofilms, and how microbes locate nutrients.

Freezing-mediated transport and organization: We study how moving freezing fronts redistribute solutes and particles, reorganize soft and porous materials, and reshape transport through freeze–thaw cycles, i.e., processes at work in permafrost, frost damage to soils and structures, cryopreservation of cells, and the freeze-casting of porous materials.

Memory and learning in fluidic networks: We design nonlinear fluidic elements whose response depends on their history, so that flow itself can store and process information without any electronics. We study how linking such elements into networks can give rise to collective switching, memory, and even learning. Such networks point toward soft machines and lab-on-chip devices that sense and compute on their own, echoing how living networks such as slime molds and fungi route flow and adapt to their dynamic environments.

We organize a weekly seminar series on soft, fluid, living matter at Yale (link).