Soft matter is the field of science concerning soft and deformable materials: such as liquids, gels, and foams. Active matter is a sub-field of soft matter that considers systems that contain active agents or particles that consume energy for self-propulsion or to exert mechanical stress on the surrounding system. In this dissertation, I present and study mathematical models for three separate systems within soft and active matter. First, I derive a continuum model for a two-dimensional suspension of active spinners by coarse-graining the equations of motions for discrete spinners. I discuss the emergence of multiple phenomena including: phase separation, formation of steady traffc lanes, and turbulent-like fluid flow for small but finite Reynolds numbers. Second, I present a phenomenological model for cell motility observed in substrate based Eukaryotic cells. I study the case of rotational motion in these substrate-based cells, driven by rotating lamellipodia waves that travel about the cell periphery. I derive the dynamics for the emergence of rotating waves and the competition between multiple different rotating waves. Finally, I consider lipid bilayer vesicles and the method of fluctuation spectroscopy, a non-invasive technique of measuring physical properties of a vesicle by analyzing its thermally-driven fluctuations. I derive higher accuracy methods for measuring the bending modulus and the membrane tension of vesicles that are within thermal equilibrium. I also discuss the use of detailed balance analysis to quantitatively study fluctuating vesicles that are out-of-equilibrium.

Creator

• Reeves, Cody Jordan

DOI

• https://doi.org/10.21985/n2-3gr1-vp50

Subject

• Applied mathematics

Language

• en

Alternate Identifier

• etdadmin_upload_772543
• http://dissertations.umi.com/northwestern:15339

Keyword

• Spinners
• Models
• Dynamics
• Soft Matter
• Cell Motility
• Active Matter

Date created

• 2020-01-01

Resource type

• Dissertation

Rights statement

• In Copyright