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Thermal Stiffening of Clamped Elastic Membranes

Speaker

Duanduan Wan, Wuhan University

Time

2019.04.09 14:00-15:00

Venue

Room 703, No. 6 Science Building

Abstract

Thermally fluctuating flexible elastic membranes are known to be more rigid macroscopically than microscopically due to a renormalization of the microscopic bending rigidity. These flexible elastic membranes includes covalently-bonded two-dimensional atomically thin membranes such as graphene and molybdenum disulfide or soft matter systems such as the spectrin skeleton of red blood cells or diblock copolymers. Recently, we used molecular dynamics to study the vibrations of a thermally fluctuating two-dimensional elastic membrane which was clamped at both ends. The fluctuation of the elastic membrane can be regarded as a superposition of its eigenmodes, which can be extracted from resonant peaks in the frequency domain of the time-dependent height. We then measured the dependence of the corresponding eigenfrequencies on the microscopic bending rigidity of the membrane. The role of thermal contraction in generating a tension when the projected area is fixed had also been taken care of. At finite temperatures we found that the effective (macroscopic) bending rigidity tends to a constant as the bare bending rigidity vanishes, consistent with theoretical predictions. I will review the study.

Bio

Duanduan Wan received her B.S. degree from Wuhan University in 2010, and Ph.D. degree from Syracuse University in 2016, working with Prof. Mark J. Bowick. Then she became a postdoc working with Prof. Sharon C. Glotzer at the University of Michigan. She is currently an assistant professor in the School of Physics and Technology at Wuhan University.