CAREER: Collective hydrodynamics within viscous interfaces: activity and assembly in membranes and monolayers

University Of California-Davis, Davis CA

Investigators

Abstract

The cooperative movement of microscopic particles embedded in the interface between two fluids is central to many biological and engineering processes. These dynamics govern the motion of proteins in cell membranes or respiratory particulate matter on lung linings and in-fluence the design of synthetic drug delivery vehicles that mimic natural cells. This award will support the development of new models and simulations to quantify and engineer these complex membrane-like assemblies. This project will describe the activity and dynamics of particles of realistic shapes, develop accurate simulations to efficiently characterize large-scale aggregates, and reveal novel strategies to engineer interactions between particles. In a tightly integrated education plan, this project will develop a cohort program specifically targeting the professional success and STEM participation of underrepresented transfer students from local community colleges via year-long mentorship and training. As part of this program, researchers and trainees will develop and disseminate open-source, interactive, instruction modules for teachers and students, aimed at promoting broad engagement with coding and engineering methods and inspiring a more competitive future STEM workforce. The main goal of this award is to firmly establish the role of large-scale hydrodynamic interactions on particle organization within viscous interfaces in a broad class of biological and biomimetic applications. While the transport of isolated, passive particles in Newtonian interfaces is well established, a rigorous platform to capture large-scale hydrodynamic interactions of realistic particle shapes in complex crowded monolayers or membranes that represent many applications is still lacking. Real systems are particularly challenging due to non-Newtonian surface rheology, the active nature of molecular motors and artificial self-propelled interfacial colloids, and the extended or deformable structure of membrane anchors and synthetic nano-rods. This project will use asymptotic theory to systematically evaluate pair interactions in a wide range of realistic non-Newtonian interfaces, develop efficient computational methods to capture large-scale surface hydrodynamics, extend these insights and tools to complex particle shape and system geometries, and develop mesoscopic mean-field models to explore large-scale structure, stability, and patterns. Put together, the analytical and numerical tools developed in this project will be broadly applicable in the rational and creative design of novel self-assembled materials on bilayers, monolayers, biofilms, and polymer membranes, going beyond the length scales and limitations of traditional interfacial engineering. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.