08:40 - 09:25
09:25 - 10:10
10:30 - 11:15
11:15 - 12:00
13:30 - 14:15
14:15 - 15:00
15:20 - 16:05
16:05 - 16:50
Piezoelectric Energy Harvesting: Fundamentals, Nonlinearities, and Metamaterial Concepts
Associate Professor & Woodruff Faculty Fellow, G. W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, USA
This lecture is centered on the fundamentals and recent trends in piezoelectric energy harvesting from dynamical systems, with a focus on effective methods of converting vibrations and structure-borne propagating waves into low-power electricity. After an introduction to piezoelectric energy conversion and linear energy harvesting concepts, leveraging designed nonlinearities and understanding inherent nonlinearities will be discussed with experimental results and model predictions via harmonic balance analysis. Intentionally introduced nonlinearities in the mechanical domain (by design) aim to increase the frequency bandwidth of usable power output. Examples of both monostable and bistable Duffing-type wideband nonlinear energy harvester configurations will be given in this context. Inherently present nonlinearities in piezoelectric energy harvesters are predominantly due to piezoelectric material softening as well as dissipative nonlinearities (due to nonlinear solid damping and/or fluid damping). The nature and manifestation of such inherent material and dissipative nonlinearities will be discussed, and their interaction with designed nonlinearities will also be demonstrated. The discussion of nonlinear energy harvesting will conclude with the combination of these mechanical nonlinearities with basic electrical circuit nonlinearities, in the presence of nonlinear non-ideal circuit components.
Another emerging area in piezoelectric energy harvesting is the leveraging of concepts from phononic crystals (PC) and metamaterials for the effective harvesting of propagating elastic waves in structures. Two PC-based gradient-index lens configurations will be discussed for the spatial focusing and enhanced harvesting of plane waves. Other than the lens designs (based on refractive index tailoring), elastic wave mirror concepts will be discussed briefly to focus and harvest propagating waves (via reflection tailoring) using structurally-embedded reflectors.
About the Speaker
Dr. Alper Erturk is an Associate Professor & Woodruff Faculty Fellow of Mechanical Engineering at Georgia Institute of Technology. His research program is centered on the intersection of smart structures and dynamical systems for various problems ranging from energy harvesting and bio-inspired actuation to metamaterials and wireless acoustic power transfer. He has published around 200 articles in archival journals and conference proceedings, 4 book chapters, and 2 books (total citations ~ 9600 and h-index: 45). Dr. Erturk is a recipient of various awards including an NSF CAREER Award (2013), an ASME Gary Anderson Early Achievement Award (2015) for early career impact in the field of adaptive structures and material systems, an ASME C.D. Mote Jr. Early Career Award (2017) for demonstrated research excellence in the field of vibration and acoustics, and two ASME Energy Harvesting Best Paper Awards (2015, 2017). He is an Associate Editor for Smart Materials & Structures (IOP), Journal of Intelligent Material Systems & Structures (SAGE), Journal of Vibration & Acoustics (ASME), and Journal of Energy Engineering (ASCE). He was an Elected Member of the ASME Technical Committee on Vibration & Sound, the Founding Chair of the ASME Energy Harvesting Technical Committee, and is currently an Elected Member of the ASME Adaptive Structures & Material Systems Branch.
He served on the organization and program committees of various conferences (ASME, SPIE, PowerMEMS, etc.) and is currently the Chair for the 2018 ASME IDETC Mechanical Vibration & Noise Conference, and for the 2018 SPIE Smart Structures/NDE - Active & Passive Smart Structures & Integrated Systems Conference. Dr. Erturk is a Fellow of ASME.