CAREER: Transport and collective behavior of microswimmers in porous media

This CAREER award will investigate how bacteria move in porous environments such as tissue, gels, soils, and sediment. Bacteria are examples of microswimmers, a class of particles that can propel themselves through fluid. The investigators will use 3D printing to fabricate porous environments with controlled pore structures, and they will use microscopy to observe how the bacteria move.

These studies will reveal how the motion and self-organization of bacteria depend on the properties of their environment, the properties of the cells themselves, and interactions among the cells. The project will provide new research experiences and educational modules for high school, undergraduate, and graduate students, with a specific focus on students from under-represented groups.

It will also enable new presentations and demonstrations to inspire and engage K-12 students at the Princeton Public Library and at local schools. Finally, it will provide opportunities for discussion forums, workshops, and dissemination of computational tools to the broader scientific community.

This project will develop new experimental techniques and mathematical models to generate a fundamental understanding of microswimmer transport and collective behavior in porous media. The work will focus on bacteria, an archetype of microswimmers that can move through fluid by flagellar propulsion. Two fundamental questions will be addressed.

First, how is single-cell motility altered by pore-scale confinement - specifically, how does motility depend on the properties of the cells and of the porous medium? Second, how do cell-cell interactions guide collective behavior in porous media? By connecting cellular properties, porous medium properties, and motility/collective behavior, this work will generate knowledge to enable prediction and control over bacterial transport and organization.

Results from this project will help practitioners control bacterial behavior in applications such as treating infections, microbial drug delivery, using soil bacteria for agriculture, and bioremediation. More broadly, this work will provide a foundation for future studies of microswimmers in complex environments and will guide the design and use of synthetic microswimmers for applications ranging from drug delivery to chemical sensing.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.