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Dan Goldman - Professor
(404) 894-0993
Summary Sentence: Join the School of Physics as they present their Condensed Matter & Physics of Living Systems Seminar featuring guest speaker Andrej Košmrlj.
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Andrej Košmrlj
Wrinkling instability of compressed stiff thin films bound to soft substrates has been studies for many years and the formation and evolution of wrinkles is well understood. Similar wrinkling instabilities also play important role in biology during the development of organs, such as brains and guts, and during the formation of bacterial biofilms grown on soft substrates. In recent years, the wrinkling instability has been exploited to create structures with tunable drag, wetting, adhesion, and to create a template for wire formation. While these studies successfully demonstrated the proofs of concepts, the quantitative understanding is still lacking, because very little is known about how wrinkled surfaces deform in response to interactions with environment. To address this issue, we investigated the linear response of wrinkled structures to external forces. By mapping the problem to the Landau theory of phase transitions, we demonstrated that the linear response to external forces diverges near the onset of wrinkling instability with the usual mean field exponent found in critical phenomena. Interactions with environment also dictate the morphology of wrinkled patterns in growing biological systems.
A discussion on the formation of wrinkling patterns in bacterial biofilms grown on agar substrates, which usually have radial stripe patterns near the outer edge and zigzag herringbone-like patterns in the core. The observed wrinkling patterns result from uneven stress distribution in the biofilm as a consequence form the depletion of slowly diffusing nutrients underneath the biofilm, which are required for the bacterial growth.
Click here for Professor Andrej Košmrlj's Research Group page.
