Grzegorz Szamel of Colorado State University is supported by an award from the Chemical Theory, Models and Computational Methods program in the Chemistry division to study active matter. Active matter systems consist of objects that take in energy from their environment and use it to execute directed motion. Examples include bacteria and Janus colloidal particles, particles with two distinct sides with different properties. Janus particles can move due to a chemical reaction that is catalyzed on one of these sides. Because active matter systems are constantly consuming and dissipating energy, they are never in equilibrium. They are driven internally, at the level of individual components. Active matter systems exhibit fascinating macroscopic structure and dynamics, for example spontaneous self-assembly or pattern formation. The fundamental understanding of the relation between the activity and the macroscopic behavior may lead to practical applications, e.g. the design and assembly of new materials. Grzegorz Szamel and his group develop new methods to study how active matter systems flow and the role of fluctuations in these systems.
The motivation for this research comes from the combination of the absence of a general theoretical framework to describe active matter, the increasing sophistication of experimental results in this area and the practical importance of active matter systems in chemical, biological and materials science settings. Szamel and his research group derive and test new methods to study the viscoelastic properties of athermal active fluids. Building on recent advances in out-of-equilibrium small thermal systems, they are developing stochastic thermodynamics of small active matter systems. Finally, they are studying the non-equilibrium features of active glassy fluids. They are investigating effective temperatures, microscopic currents and entropy production rates in these systems. The long-term goal of this research is to develop a fundamental understanding of the properties of active matter.
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.