MSE Talk: Mark Paul

Speaker: Professor Mark Paul, Virginia Tech

Title: Small Elastic Beams in Fluid as a Testbed to Explore Physics from the Continuum to Molecular Scales

Abstract: The multimodal dynamics of macroscale beams are central to many important and familiar technologies. If the dimensions of a beam are uniformly reduced, the effective spring constant  decreases while the natural frequency increases.  These favorable trends continue to drive the development of micro and nanotechnologies with unprecedented sensitivities. However,  in this talk I focus on how measurements of the dynamics of small elastic objects in fluid have also paved the way for fundamental studies of interesting and important physics.  This has provided new insights into the interactions of fluids and solids when the dynamics range from linear to nonlinear, deterministic to stochastic, and continuum to molecular. In particular, the multimodal dynamics of a small elastic beam will be explored for a wide range of conditions when the beam is driven externally or by Brownian motion alone. The beam dynamics will be quantified as the deflections become large and nonlinearity becomes significant.  The fluid motion caused by an oscillating elastic object yields an important frequency dependence on the dynamics and provides insight into the role of nearby surfaces and the subtle correlations that occur between arrays of elastic objects.  

Bio: Mark Paul is Professor and Associate Department Head of Faculty Affairs for the Department of Mechanical Engineering at Virginia Tech. Paul received a PhD in Mechanical Engineering from UCLA and was a postdoctoral scholar at Caltech in theoretical physics prior to joining Virginia Tech in 2004. Paul's broad research interests are centered on fundamental questions that are investigated using approaches based in computational science and engineering. Paul's recent research has focused on the thermal fluctuations of small elastic objects, coupled dynamics of oscillating objects in a viscous fluid, emergence and significance of nonlinearity at the nanoscale, chaotic dynamics of large systems, and the pattern formation of Rayleigh-Benard convection.