Events Daily

Thursday, April 27, 2023

Equity & Inclusion Committee
Event Type: Other
Time: 12:30 PM - 2:00 PM
Location: 726 Broadway, 901, Sm Conf

Investigating Gravitational Effects on Large and Small-Scale Structures of the Universe
Ekapob Kulchoakrungsun
Event Type: Oral Defense
Time: 1:00 PM - 3:00 PM
Location: 726 Broadway, 902, Lg Conf
Abstract: COMMITTEE: Professor Anthony Pullen (Thesis Advisor) Professor Michael Blanton Professor David Grier Professor Matthew Kleban Professor Roman Scoccimarro

Mechanical Phase Transitions and Elastic Anomalies in Fibrous Networks
Fred MacKintosh, Rice University
Event Type: Physics Dept Colloquium
Time: 4:00 PM - 5:15 PM
Location: 726 Broadway, 940, CCPP Seminar
Abstract: The mechanics of cells and issues are largely governed by scaffolds of filamentous proteins. Particularly common examples of these are the collagen fiber networks of extracellular matrices. There is now increasing evidence that the mechanics of such fibrous structures are governed by underlying mechanical phase transitions reminiscent of the rigidity transition identified by Maxwell for macroscopic engineering structures: networks of struts or springs exhibit a continuous, second-order phase transition at the isostatic point, where the number of constraints imposed by connectivity just equals the number of mechanical degrees of freedom. By contrast, fibrous networks in 3D exhibit a line of critical transitions as a function of strain rather than connectivity. These transitions have shown remarkable richness, including non- mean-field critical behavior. We will present recent theoretical predictions and experimental evidence for such strain-controlled mechanical phase transitions in biopolymer networks, as well as some of the elastic signatures and anomalies such as unexpectedly large Poisson ratios and inverse Poynting effect governed by these transitions.