Reconfigurable Elastic Metasurfaces for Anomalous Wavefront Shaping

with Serife Tol, assistant professor
Department of Mechanical Engineering
University of Michigan

rescheduled to Nov. 16, 3:00 pm
440 Goodwin Hall

Architected materials are periodically engineered materials designed with specific unit structures or architectures. As a result of their internal structures, they exhibit unique characteristics compared to traditional homogeneous materials and enable unprecedented mechanical properties. Well-known examples of architected materials include metamaterials and phononic crystals, which are designed to control the propagation of mechanical waves and used for applications such as invisibility cloaks, superlenses, and waveguides. Emerged more recently, metasurfaces offer new alternatives for wave control with the most compact footprint, which is especially desired for low-frequency applications. Their anomalous control over mechanical waves makes metasurfaces valuable tools in fields ranging from acoustics and structural engineering to medical imaging and energy harvesting. This talk will highlight reconfigurable elastic metasurfaces for tunable wavefront control without the need for irreversible structural modifications.  We will theoretically and experimentally demonstrate how to tailor the desired phase modulation and achieve wavefront manipulation by tuning either the structural elements of the passive metasurface or the external electrical stimuli on the electromechanical metasurface. We will discuss distinct design approaches by taking inspiration from origami art to create a folded metasurface, adopting locally resonant metasurface elements based on threaded rods and nuts, and implementing piezoelectric-shunted metasurface units.

Serife Tol is an Assistant Professor in the Department of Mechanical Engineering at the University of Michigan (UM), Ann Arbor. She received her Ph.D. (2017) from Georgia Institute of Technology and her M.S. (2012) and B.S. (2009) degrees from Middle East Technical University (METU, Ankara, Turkey), all in mechanical engineering. Dr. Tol’s research interests revolve around smart materials and dynamical systems with an emphasis on phononic crystals, metamaterials, and metasurfaces for interdisciplinary applications such as energy harvesting, sensing, vibration mitigation, waveguiding, and filtering. Her research has been funded by the National Science Foundation (NSF), the Defense Advanced Research Projects Agency (DARPA), and the Department of Energy (DoE). She recently received the John F. Ullrich Education Excellence Award from UM College of Engineering.