Session: SYMP 3-2: Advanced Material Systems

Paper Number: 140491

140491 - Passive Band Gap Enhancement in Piezoelectric Metamaterials via Non-Local Resonance 

We present a new, passive technique to dramatically enhance the bandwidth of resonant band gaps in piezoelectric metamaterials. Locally resonant (LR) band gaps form from the hybridization of a localized, electrical dispersion curve and the underlying elastic dispersion of the piezoelectric waveguide. The bandwidth of the LR band gap is inherently limited by the electromechanical coupling of the system; thus, negative capacitance, which increases the effective electromechanical coupling factor, is typically used to increase the bandwidth of the band gap. In this work, we take a different approach to increase the band gap’s bandwidth: rather than attempt to increase the electromechanical coupling, we strengthen the hybridization by modifying the electrical dispersion curve using non-local shunt circuits. Non-local inductance between unit cells results in an electrical dispersion curve that hybridizes significantly more strongly with the underlying elastic dispersion curve, resulting in a partial, “non-locally resonant” (NLR) band gap that is significantly more broadband than the corresponding LR band gap. If the electrical lattice is designed appropriately, the wave modes available within the partial band gap are predominantly electrical. Thus, the NLR band gap still exhibits significant attenuation of elastic waves, especially in the presence of loss in the electrical lattice, as energy is only able to propagate in the electrical lattice. Importantly, this configuration requires no power input, requiring only passive inductors, and so it does not any potential for instability as in the case of negative capacitance. We present an analytical model for both dispersion and finite-structure analysis of NLR piezoelectric metamaterials, and we show that the NLR band gap yields significant attenuation in the elastic regime. First, we investigate the behavior of the partial NLR band gap, highlighting how the electrical lattice must be designed to avoid propagation in the elastic regime. Second, we show that, like the LR band gap, it is necessary to use a sufficient number of unit cells to observe significant attenuation in the NLR band gap; however, this behavior is made more complex due to the electrical connections between distant unit cells. Next, we illustrate the dramatic influence of damping on the response in the NLR band gap and compare the resulting attenuation to the comparable LR band gap. Finally, we validate the theoretical results using finite-element modeling in COMSOL Multiphysics and discuss plans for experimental validation. We envision that this approach of dispersion engineering using non-local interactions will enable the creation of more broadband band gaps in acoustic metamaterials more broadly.

Presenting Author: Christopher Sugino Stevens Institute of Technology

Presenting Author Biography: Dr. Christopher Sugino is an Assistant Professor in the Department of Mechanical Engineering in the Schaefer School of Engineering and Science at Stevens Institute of Technology. His research focuses on elastic and acoustic wave propagation in smart structures and metamaterials, with applications in noise/vibration control, aerospace engineering, and biomedical ultrasound. He is a recipient of the NSF CAREER Award (2024) in Dynamics, Controls, and Systems Diagnostics. He also received the 2021 Doak Award from the Journal of Sound and Vibration and the 2020 Sigma Xi Best Ph.D. Thesis Award from Georgia Tech. He received his Ph.D. in Mechanical Engineering from the Georgia Institute of Technology in 2019 and his B.S. in Engineering from Harvey Mudd College in 2015.

Authors:

Muhammad Bilal Khan
Christopher Sugino