Modeling Colloidal Surfaces using Method of Regularized Stokeslets

Bacterial motility can be hindered or enhanced by interactions with different types of surfaces in a fluid environment. To study bacterial motion near a rough surface, we want to simulate a layer of randomly-distributed microspheres to represent a surface constructed of lipids. Our goal is to incorporate physically realistic forces into our simulations to make quantitative predictions of fluid-surface interactions. Using the method of regularized Stokeslets, we validated the Brownian motion of a particle due to thermal energy in the fluid environment. We further included an interparticle force that depends on the distance between two particles to examine how the forces affect the fluid flows. We compared the fluid flows predicted by two models: (1) a regularized Stokeslet point at the center of a particle, and (2) a sphere whose surface is discretized by regularized Stokeslet points. In future work we will compare the viscosity as predicted by the sphere model and the point model.