Modeling and Simulating Particle Motility and Transport in Microfluidics

Gess Kelly, Computational Researcher and PhD Candidate, Brandeis University

Hopeman 224

In this talk, I will discuss two collaborative projects, first on modeling colloidal deposition in a network of beads and later, polymerization-based active matter. Experiments on transport of colloidal particles in pressure-driven systems of packed beads have shown that at lower fluid pressure drop, particles deposit locally at the inlet, while at higher fluid pressure drop, they deposit uniformly along the direction of flow. Our network-based approach, mathematical model, and agent-based simulations capture these essential qualitative features observed in experiments. We show that two global parameters, fluid pressure and shear stress, control the outcome for the deposition profile. In the second part of the talk, I will discuss challenges and progress on an ongoing project in modeling actin comet tails. Organisms such as the bacterium Listeria monocytogenes exploit actin polymerization to gain motility. Similarly, self-organized motility has been realized in vitro through colloidal systems that use actin polymerization to self-propel. We aim to model the flocking behavior observed experimentally involving these active beads by numerically solving a set of reaction-diffusion-based differential equations. The goal of the project is to use simulations to further test hypotheses on how system parameters such as actin concentration, particle number density, and particle-to-system size ratio control the collective behavior of these active beads.