Flagellated micro-swimmers in a viscous fluid

Thursday, May 31, 2018 - 11:10am - 12:00pm
Lind 305
Sookkyung Lim (University of Cincinnati)
Swimming bacteria with helical flagella are self-propelled micro-swimmers in nature, and the swimming strategies of such bacteria vary depending on the number and the position of flagella on the cell body. In bacterial flagella-based propulsion, the major driving force comes from a rotary motor that is embedded in the cell body and is connected to the flagellar filament via a universal joint ‘hook.’ We will introduce two microorganisms, multi-flagellated E. coli and single-flagellated Vibrio A. The Kirchhoff rod theory is used to model the elastic helical flagellum together with the hook and the penalty method is employed to describe the dynamics of the rigid cell body. The hydrodynamic interaction between the fluid and the cell is represented by the regularized Stokes formulation. In this talk, we will focus on (1) how polymorphic transformation of the flagellum affects the dynamics of E. coli and (2) how hook’s buckling reorients swimming bacteria Vibrio A in new directions.