NSF-BSF: Dynamics of flowing particles in soft confined systems

University Of California-Riverside, Riverside CA

Investigators

Abstract

This award will investigate how particles flow in complex compliant microscale systems, in which deformation of either the particles or the confining environment affects particle transport. Many biological and engineered structures at the microscale, such as cell membranes, biofilms, and microfluidic devices, are soft and thus easily deformed by fluid flow. Red blood cells deform when flowing in narrow capillaries, and swimming microbes and flowing microparticles can cause cell membranes to bend and deform. These deformations modify the motion of the suspended entities (e.g., cells or microorganisms) as a result of interactions with the carrying fluid. The project will quantify these interaction mechanisms, which are important to understand microscale biological transport, and to build biomimetic systems that use compliant structures to manipulate suspensions of particles or cells for biomedical applications. Furthermore, this award will foster education and outreach activities by engaging, or exposing undergraduate and graduate students, as well as middle and high-school teachers, to its research. As a collaboration between the University of California, Riverside and Tel Aviv University, it will also serve to enhance the participation of under-represented groups, including women, in both Riverside County and Tel Aviv (Israel). This award will investigate the dynamics of particulate suspensions confined by flexible elastic membranes, which are ubiquitous in biological environments at the microscale. The researchers will develop a fundamental understanding of hydroelastic mechanisms of suspension transport in microscale systems, using a combination of analytic theory, numerical simulations, and experiments. Over the course of the project, the international team will develop (i) novel theoretical and reduced-order models of hydroelastic interactions between particles near membranes, (ii) a new nonlinear hydroelastic mobility framework, complemented by numerical simulations, of many-particle dynamics in proximity to membranes, and (iii) new experimental studies to visualize, characterize, and quantify particle-membrane interactions in macroscopic and microscopic settings. Finally, the fundamental insights obtained from these studies will be used to develop a microfluidic device to manipulate and sort vesicles and soft particles based on their mechanical and geometric properties. 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.