Undergraduate Project Reports

Summer 2017 Student Report:

Modeling microorganism swimming using Kirchhoff rod immersed in Stokes flow

Abstract: Many species of microorganisms that live in fluid environments, including certain bacteria and sperm, propel themselves through the fluid using one or more flagella. Our work entails creating a computational model for how mono- flagellated organisms swim by immersing an elastic lament known as a Kirchhoff rod in Stokes flow. In doing so, we successfully replicate the nature of how such microorganisms maneuver through their environment by propagating a wave down the length of the rod, causing it to move forward. We find that by making the oscillations asymmetrical, the rod's trajectory will begin to turn. By precisely controlling the oscillations of the rod, we are able to steer the organism in any desired direction. Using this method of steering, we can model the process of chemotaxis, which many microorganisms use to swim towards regions with a high concentration of certain bene cial chemicals. In this paper, we present two methods for driving the rod to a target point, and two methods for guiding the rod to a maxima of a chemical gradient.

Summer 2016 Student Report:

Breaking Viscoelastic Networks in Stokes Flow

Abstract: Many biological substances exhibit both viscous and elastic properties and are immersed in a highly viscous fluid. These may include blood clots, bacterial biofilms, and mammalian reproductive cells. We have constructed a computational model of such systems based on the previous research by Wrobel, Cortez, and Fauci and incorporated breaking, dynamic elements to describe how these materials break apart when subjected to enough external stress. Our work provided us with new insights into how networks break apart when immersed in different types of flows, and when different parameters such as the stiffness of connections are varied. Using our findings, we have come up with some general hypotheses about several biological applications of our model.