Daniel Beller

2020 Hellman Fellow


Asssistant Professor Physics
UC Merced

Project title: Modeling 3D Active Nematics Through their Topological Defects

Project description: This project will develop models to understand and predict the complex motions of three-dimensional active liquid crystals. These are materials that behave like fluids, but with an elasticity that resists deformations as well as other internal forces that amplify deformations—a competition that results in flows of a chaotic and continually shifting nature. Active nematic behavior has recently been identified as underlying motion and development in a wide variety of biological and synthetic systems, including growing bacterial colonies, bacterial swarms, epithelial layers, neural stem cells, cytoskeletal biofilaments, and rod-shaped granular particles. The intricate structures found in active liquid crystals are characterized by a specific kind of topological defect, which in this case is a string-like concentration of deformation. Through this project we will understand the dynamics of the chaotic flows by finding laws governing the motions of these topological defects, generalizing previous work on two-dimensional monolayers to fully three-dimensional materials. The physical principles of the modeling approach we use apply at a wide range of size scales and material properties, so the results are expected to apply generally to a diverse set of systems.