(4im) Microscopy, Rheology, and Dynamics of Microbial Communities in Complex Environments

Soft and living matter is rich with examples of how microscale organization influences macroscale properties. For instance, the cracking of glass depends on the local packing of grains, the organization of bacteria within the gut affects nutrient absorption, and the network structure of collagen fibers determines the mechanical properties of articular cartilage. Understanding this micro-macro coupling is challenging for many reasons, including the difficulty of imaging through complex geometries and the numerous interactions at play. During my PhD and postdoc, I have made progress in addressing these challenges within different soft matter systems. In my PhD, I developed a mean-field, universal scaling theory for shear thickening suspension viscosity, leading to several suspension-agnostic techniques for tuning viscosity. Currently, as a postdoc, I am interested in the chemotaxis and growth of bacterial communities in complex environments, where we use transparent hydrogel packings as a model system for confined spaces, such as soil and biological tissues.

Building on these findings, in my independent lab, I plan to use a combination of rheology, microscopy, and statistical mechanics techniques to explore how activity-driven microscale interactions affect the emergent function of microbial communities in complex environments. Specifically, I will focus on these three research areas:

1. 1. Active tuning of suspension rheology using bacteria as dopants: Previous research in dense suspensions has led to a "constraint-based" description of suspension rheology and the development of a universal function for passive suspension rheology. I plan to study how the injection of activity at the microscale alters the flow behavior of suspensions. My goal is to develop a suspension mean-field theory to understand this behavior and ultimately create a universal framework for understanding and tuning both active and passive suspensions.
2. 2. Mechanical stability of microbial communities: Microbial communities often inhabit spatially heterogeneous environments characterized by confinement, viscoelasticity, and local stresses. I plan to use a combination of mechanical probes and microscopy to investigate how local heterogeneities and mechanical perturbations influence the stability and growth of microbial colonies in realistic environments resembling the colon.
3. 3. Structured microbial communities for optimal chemical transport: Within microbial communities, the density of microbes is often highly heterogeneous. How does this distribution affect the transport of metabolites? I plan to engineer microbial communities with varying spatial cell distributions and measure metabolite transport through these communities, aiming to design optimal microbial filters for bioremediation applications.

These research directions have implications in understanding the growth and mechanical properties of microbial communities in real-world fluctuating systems like the human gut, and in applications such as designing tunable active suspensions, and engineering biosystems with optimal transport and mechanical stability.

Teaching interests: My background in physics, and my minor in Chemical Engineering has equipped me to teach a number of undergraduate courses including heat and mass transfer, fluid mechanics, thermodynamics, and statistical mechanics. In addition, I would be interested in developing elective courses in soft matter mechanics, or colloids and interfaces.