Kathleen Stebe
Goodwin Professor of Applied Science and Engineering, Professor of Chemical and Biomolecular Engineering, University of Pennsylvania
This lecture honors the distinguished career of William R. Schowalter, whose accomplishments span seminal research in fluid mechanics, visionary academic leadership as department chair at Princeton and dean of engineering at the University of Illinois at Urbana-Champaign; and high-level international engagement as senior adviser to three presidents at the National University of Singapore and King Abdullah University of Science and Technology.
Reflecting Bill’s broad contributions to chemical engineering, the lecture’s focus will alternate on a yearly basis between fluid mechanics research, broadly understood to include complex fluids and soft condensed matter, and typically delivered by an academic speaker, and topics of general interest to our profession, the latter typically delivered by an industrial speaker.
The William R. Schowalter Lecture will be given by Kathleen J. Stebe, Goodwin Professor of Applied Science and Engineering, Professor of Chemical and Biomolecular Engineering, University of Pennsylvania.
Physically intelligent colloidal systems
Kathleen J. Stebe, Goodwin Professor of Applied Science and Engineering, Professor of Chemical and Biomolecular Engineering, University of Pennsylvania
Active colloids include bacteria which swim by action of flagella and biomimetic self-propelled colloids that move by consumption of chemical fuel. We have been developing the concept of Active Surface Agents, active colloids trapped at fluid interfaces to promote interfacial transport. Fluid interfaces are highly non-ideal, complex domains that impose constraints that alter swimming behavior. We study the bacterium Pseudomonas Aeruginosa (PA01) at interfaces and characterize several distinct swimming behaviors. We measure the flow generated by these swimmers using a recently developed flow visualization method correlated displacement velocimetry. The flow field has unexpected asymmetries whose structure we describe fundamentally using hydrodynamic theory. We explore the implications of our results on mixing in the interface and in the design of biomimetic systems. By understanding how biological swimmers move at fluid interfaces, we can develop design rules for artificial biomimetic systems to promote transport at fluid interfaces with broad implications in chemical engineering processes.
Supported by the AIChE Foundation
