Origami Acoustics and Mechanical Metamaterials: Recent Discoveries with Adaptive Structural and Material Systems for Elastic and Acoustic Wave Propagation Control
Speaker: Dr. Ryan L. Harne, The Ohio State University
Date: Oct 27, 2017; Time: 2:30 pm Location: UTEB 175
Abstract: As form follows function, so shape governs the properties of structural and material systems. Recent studies on adaptive structures have capitalized on these connections to realize unprecedented tunability of system properties and functionality by passive or active transformations of system configuration. This two-part presentation describes integrated theoretical and experimental research efforts that advance these principles to deliver large control over wave propagation properties of adaptive structural and material systems. In the first part, a method is presented that broadly enhances capabilities for acoustic transducer arrays to guide wave energy via harnessing foldable, origami-based tessellations. The foldable arrays enable orders of magnitude change in acoustic energy delivery to points near and far from the surface of the tessellation using shape transformations and without resorting to digital control, and may find future application for instance for medical ultrasound therapy devices transported and deployed in the human body. In the second part of the presentation, strategies to leverage cellular architecture within elastomeric material systems are described that give rise to unusually large elastic wave damping properties. Using this concept, shock energy into the elastomeric metamaterials is found to be dramatically dissipated by tuned pre-compression constraint, and dampened more effectively than the heavier solid elastomer material. This concept is prime for future applications of lightweight personal protective equipment and recoverable shock absorbers. All together, these results encourage ongoing study to probe relations between shape and properties in adaptive structural and material systems to capitalize on potentials for large wave propagation control.
Biographical Sketch: Ryan L. Harne is an Assistant Professor in the Department of Mechanical and Aerospace Engineering at The Ohio State University where he directs the Laboratory of Sound and Vibration Research. Dr. Harne received the Ph.D. degree in Mechanical Engineering at Virginia Tech in 2012. From 2012 to 2015, Dr. Harne was a Research Fellow at the University of Michigan. His research expertise falls in the areas of vibration, acoustics, mechanics, and nonlinear dynamics. The outcomes of his research efforts have included several patents pending, one book, over 40 journal publications, and over 40 conference proceedings, alongside numerous students mentored and guided through their academic programs. Dr. Harne is active in ASME, ASA, and SPIE, where he serves in several elected and appointed roles. Dr. Harne was awarded a 2017 Air Force Research Lab Summer Faculty Fellowship from the Air Force Office of Scientific Research, the 2017 ASME Best Paper Award in Structures and Structural Dynamics, the 2016 Haythornthwaite Young Investigator Award from ASME, and the 2011 ASA Royster Award. He currently serves as an Associate Editor for The Journal of the Acoustical Society of America, Proceedings of Meetings on Acoustics.