Collaborative Research: Dynamic Clustering and Rheology of Magnetic Janus Particles with Shifted Dipoles

University Of Puerto Rico Mayaguez, Mayaguez PR

Investigators

Abstract

The goal of the project is to engineer the flowability of a fluid, i.e., the ease with which a fluid flows, by addition of active magnetic particles with unique magnetic properties. These particles can be manipulated by a combination of an external magnetic field and an internal chemical gradient. Fluids with varying flowability are important for common technologies, such as printers, fluid shock absorbers, fluid property sensors, biomedical devices, and body armor. Control of the flowability will enable longer lifetimes, broader applicability, reduced cost, and increased stability of the fluids and devices. The proposed research will investigate the assembly properties of active magnetic colloids using experimental and computational techniques. Additional benefits of these studies are the creation of a toolbox for the design of fluids that have their flowability tailored to a particular application. The research addresses the need for an in-depth understanding of the assembly behavior of active magnetic Janus particles with shifted dipoles. In systems with shifted dipoles, the magnetic dipole axis is shifted away from the center of mass of the particle, thereby providing additional control over particle orientation and response. In combination with on-board propulsion, particles with shifted dipoles represent a new and exciting class of active materials. The research described will advance our understanding of magnetic particle interaction, active matter, and the rheology of complex magnetic fluids. This work will enable future studies in which, for example, Brownian Dynamics simulations are used to predict long-time dynamics and to discover novel structures that are difficult to accomplish or detect experimentally. More broadly, research described in the proposal will advance our understanding of the intrinsic role of forces and torques in the structure of complex fluids, thus providing important insights into the statistical physics of out-of-equilibrium systems and enabling researchers to better engineer and utilize many body dynamics in the microscopic regime. The educational goals of this proposal will leverage the collaborative environment between the two participating institutions to enhance student education at various stages and thereby strengthen the diversity of the STEM workforce pipeline.