Abstract

In this seminar I will be talking about various results from my PhD.

I will begin with an APS -style 10 minute presentation of my work on the active versus passive bundling of flagella. In this work we categorise the various physical effects that contribute to the formation of a flagellar bundle, and derive a minimal model that gives us an understanding of their respective importance in the bundling process. We find that passive effects, ie. those due to the fact that a finite cell body is translating, dominate over hydrodynamic interactions for most parameter configurations.

Next I will briefly present some mathematical results that emerged as a byproduct of this project. Specifically, we derived new expressions for the flow due to rotlet singularities near a no-slip sphere, that are more useful in numerical calculations and physically intuitive than existing formalisms.

Finally I will present to you some recently finished work on the irreversible hydrodynamic entrapment of cargo particles by surface rollers that was done in collaboration with Soichiro Tottori in the Cavendish Laboratory. We analysed an irreversible hydrodynamic trapping effect, analogous to deterministic lateral displacement, by which microscopic rollers can transport cargo near an interface. Our work features a phase diagram for feasible parameter configurations, as well as two theoretical models explaining the physical mechanism.