MechE Seminar: Understanding of Solid-Fluid Transitions in Embryonic Tissues by Mechanics Principles


Event details

Date 09.02.2023
Hour 09:0010:00
Speaker Dr. Sangwoo Kim, Department of Mechanical Engineering, University of California, Santa Barbara
Location Online
Category Conferences - Seminars
Abstract: Tissue structure, dynamics, and physical states are tightly controlled by collective interactions at cellular and subcellular scales. To theoretically understand these relations across multiple length scales and time scales, we develop Active Foam Model that incorporates essential cellular features of embryonic tissues, namely the existence of extracellular spaces, complex cell shape, and non-equilibrium tension fluctuations at cell-cell contacts. Active Foam Model recovers two distinct modes of solid-fluid transitions in equilibrium, jamming transition and density-independent transition as limiting behaviors and explains a novel non-equilibrium rigidity transition governed by junctional tension fluctuations. A direct measurement of stress relaxation as well as cell
rearrangement in elongating zebrafish tailbud tissue shows that the observed tissue fluidization is driven by stochastic tension dynamics. We further extend Active Foam Model to study the role of nuclei in tissue architecture and tissue physical states and discover a nuclear jamming transition governed by nuclear volume fraction and nuclear aspect ratio. These results highlight the broad applicability of Active Foam Model to understand embryonic development and tissue morphogenesis.

Biography: Sangwoo Kim is a postdoctoral fellow in the Department of Mechanical Engineering at the University of California, Santa Barbara. He completed his graduate degree in Theoretical and Applied Mechanics at the University of Illinois at Urbana-Champaign where he investigated relations between statistics, geometry, and mechanical states in cellular matters. His current research focuses on theoretical understanding of biological and living systems as well as soft and active matter using mechanics and physics principles. His research interests include embryonic development, tissue morphogenesis, structure and mechanics of soft materials, inherent structure of amorphous materials, and non-equilibrium dynamics of active matter.

Practical information

  • General public
  • Free


MechE Seminar: Understanding of Solid-Fluid Transitions in Embryonic Tissues by Mechanics Principles