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Events - Weekly

<<   April 2016   >>
Sunday, April 24
Monday, April 25
Tuesday, April 26
Wednesday, April 27
Seminar 4/27/2016 - Sascha Hilgenfeldt, University of Illinois: Cellular Matter: Morphology and Mechanics from Tilings to Tissues
Abstract: The term Cellular Matter is used for materials consisting of separate neighboring domains that fill space in two or three dimensions. Whether ordered or disordered, the domain structure is a crucial factor in understanding overall material properties ranging from mechanical elasticity to long-time aging. Important examples range from foams and emulsions to polycrystals and biological tissues. In all cases, the discrete domain structure provides challenges to both the statistical description of the morphology (under a global space-filling constraint) and to a mechanical description of equilibrium or non-equilibrium material states. Focusing primarily on ordered and disordered biological tissues, this talk presents experimental results and provides insights from simple modeling ideas to attempt answers to a some of these challenges. We show that long-standing empirical correlations in the morphology of cellular matter, such as Lewis’ Law, can be explained analytically with a local description of neighboring domain geometry. Combining these findings with a leading order model of the mechanical energy contributions of the cellular interfaces, a connection emerges between the mechanical properties of the tissue, the statistical description of its structure, and the geometry of individual domains (cells). In epidermal tissue, we show that the equilibrium state found in our experiments corresponds to mechanically relaxed configurations of this material. Potential applications include the non-invasive diagnostics of pathological tissue changes as well as of tissue morphogenetic development, whether in vivo or in regenerative medicine.

Bio: Sascha Hilgenfeldt obtained his diploma degree in physics from TU Munich and his PhD in physics from Marburg University. After a post-doctoral fellowship at Harvard University, he held faculty positions at University of Twente (The Netherlands) and at Northwestern University before joining the University of Illinois at Urbana-Champaign. His research is concerned with the shape and dynamics of interfacial structures, ranging from oscillating micrometer-scale bubbles that drive novel microfluidic flow devices to the investigation of foams and biological cell shapes, the mechanical role of cell-cell adhesion, and the morphological statistics of tissues.

All seminars are held on Wednesdays from 12:00 noon-1:00 p.m. in the Bowen Hall Auditorium Room 222. A light lunch is provided at 11:30 a.m. in the Bowen Hall Atrium immediately prior to the seminar.
Bowen Hall Auditorium  ·  12:00 p.m. 1:00 p.m.
Thursday, April 28
Friday, April 29
Saturday, April 30