Weaving microscale transport via symmetry and geometry principles

Dr. Bin Liu is an Associate Professor of Physics at the University of California, Merced.

Abstract: Symmetry and geometry are principles that have been used to understand motion and structures across disciplines and to robustly approach distinct phenomena. By applying these symmetries and geometries to microscale flows, we can reveal surprising transport behaviors in fluids and their entrained microorganisms. In this talk, I will first demonstrate that geometry can be an unexpected factor in determining bacterial transport in structured media, introducing an anomalous dependence on cell size: short cells are often trapped, while long cells navigate smoothly through structures. Additionally, I will present the use of symmetry principles, including symmetry groups, to separate fundamental functions of microfluidic flows, such as trapping and displacing particles. This separation of functions introduces new capabilities in microfluidics, enabling accurate and multiplexed manipulation of microscale particles without perturbations, as orthogonal to traditional trap-based micromanipulation methods.

About: Dr. Bin Liu is an Associate Professor of Physics at the University of California, Merced. He received his Ph.D. in Physics, followed by a postdoctoral stay at the Courant Institute of Applied Mathematics at New York University. Before joining UC Merced, he conducted his postdoctoral research at Brown and Cornell University, studying a variety of biology-inspired physics problems. His research interests focus on the underlying geometric, topological, and symmetry-based principles in complex mechanics, especially those involved in bacterial transport and cell-environment interactions. Dr. Liu is a Hellman Fellow and a recipient of NSF CAREER Award in 2020.