Computer simulations

Computer simulations of bodies deforming in flows: microorganism swimming (top left), viscous erosion (with graduate student Will Mitchell, top right) and membranes in liquid crystals (with postdoc Art Evans, bottom).


Pinpointing how tiny organisms and cells make their way through the body can help unlock mysteries about global human health.

In our group, which includes talented graduate students, post-docs and undergraduates, we use mathematics to examine how biological fluids interact with immersed bodies. Because these fluids are filled with materials such as blood cells and long, flexible molecules, they don’t always behave like water.

For example, blood is easier to move the harder you push on it, and mucus can act like both a fluid and an elastic solid.

My team solves problems ranging from the locomotion of microorganisms to the flow of liquid crystals and we develop methods for accurately computing them.

The goal is to uncover basic physical principles, hoping to help future generations better understand microbial evolution and human health.

For example, many microorganisms swim in mucus, including mammalian spermatozoa in cervical fluid and Lyme disease bacteria in the matrix of our skin. Some swim faster when the environment becomes more elastic and some swim slower, but nobody knew why.

We found mathematically that organisms should enjoy a speed boost in more elastic fluids if the helical shapes of their propeller-like flagella – appendages enabling them to swim – have a large enough radius.

By studying one problem, we usually gain insight into seemingly unrelated questions. We are now using tools developed in our last project to solve problems in geophysics and material science.

Through careful investigation of our physical universe, I am excited to help build the knowledge that supports discovery and real-world application.