Toward the Two-Way Coupling between Active Matter and Transport Barriers

University Of Pittsburgh, Pittsburgh PA

Investigators

Abstract

Unsteady flows in natural and engineering systems, such as in the ocean and in industrial processes, play a fundamental role in the transport and mixing of submerged particles and chemical substances. Transport barriers organize flows into distinct regions with large scale coherent structures, and, thus, control the mixing of passive particles and substances. For example, transport barriers can be exploited to predict oil spill patterns. However, less is known about how these transport barriers affect the transport and mixing of active matter and vice-versa. Despite evidence that aquatic organisms, such as fish schools and phytoplankton, could affect transport in the ocean, a systematic understanding of the interplay between activity and transport barriers is lacking. Such understanding is crucial for controlling active matter in unsteady flows, with the potential to impact application areas ranging from aquatic ecology to bio-inspired designs. This award will support research to advance our knowledge of the interplay between active matter and transport barriers.  In order to reveal the two-way coupling between transport barriers and active matter, the PI will conduct experiments in electromagnetically driven laboratory flows with light-guided brine shrimp (Artemia salina). The research plan is structured around two aims: (1) to determine the non-dimensional groups that are most relevant in the coupling of active matter and large scale transport barriers, and divide the corresponding high dimensional space spanned by the non-dimensional groups; (2) to understand how small length scale in active matter percolate through scales to modify the large length scale transport barriers. The results of this research will pave the way for implementable control strategies of active matter in real-world scenarios. 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.