Session: SYMP 3-4: Programming and Modeling

Paper Number: 139348

139348 - Bandgap Enhancement Leveraging Analog Time Modulated Piezoelectric Metasurfaces 

This presentation reports on the simulation and experimental testing of a linear time-modulated piezoelectric metasurface facilitating tunable multi-resonant bandgaps formation for applications in vibration suppression and elastic wave control. Owing to their two-way electromechanical coupling between material strain and electric change, piezoelectric transducers have facilitated novel schemes for vibration control through various shunt configurations including analog circuitry, active control, digital switching, non-local interactions, and synthetic impedances. Among the most common configurations is the LC-shunt, whereby the inherent capacitance of the piezoelectric element interacts with an inductor to form a locally resonant unit cell. The existence of this coupled resonance alters the dispersive characteristics of the host material, leading to the formation of a transmission bandgap which restricts the propagation of elastic waves at matched frequencies. A significant advantage of this approach is that, by adjusting the inductance value, the operating frequency of the transmission barrier can be shifted without physical alteration of the metasurface geometry.

In this work, the inductance value is continuously updated via a digitally modulated integrated circuit embedded in a traditional synthetic impedance converter. This implementation offers precise and rapid control of an otherwise passively stable analog circuit, enabling the inductance value to take on custom time-periodic profiles with pre-specified amplitudes, frequencies, and offsets. The interaction of this periodic inductance within the locally resonant circuit dynamics redistributes the energy of the LC-oscillator into incrementally spaced sidebands, contributing to a multi-resonant band structure for the piezoelectric metamaterial. Through a combined adjustment of periodic waveform and the three associated control parameters the strength and positions of these sidebands are determined, enabling a high degree of adaptivity and programmability in the implementation of local transmission barriers. This research aims to (1) develop an analytical framework for evaluating the effect of a time-modulated impedance on the band structure of a locally resonant piezoelectric metasurface, (2) characterize the relationship between the three control parameters with the strength and frequency of the corresponding sidebands, and (3) experimentally demonstrate its feasibility for programmable, multi-modal vibration suppression.

            The presentation of this research proceeds as follows. First, the metasurface and shunt configuration is described and modeled using a lumped parameter approach with periodic boundary conditions. The additional eigenvalues introduced by the time-modulated inductance are used to pinpoint the sideband frequencies and illustrate the formation of additional bandgaps. A numerical study incorporating MATLAB Simulink and Cadence’s PSpice circuit simulation software is used to confirm the theoretical results while further investigating the relationship between the periodic control parameters and the strength of sideband formation. The experimental setup, including limitations and implementation challenges, is then discussed, followed by results demonstrating the programmable formation of multiple transmission bandgaps and frequencies for vibration suppression. The findings support and highlight the applicability of this novel approach to multi-modal vibration suppression without the added complexity of multi-branch resonator circuits or the limitations associated with more direct methods of active control. The proposed device is programmable and adaptive, allowing the local resonance and associated sidebands to be shifted to various frequencies in order to suppress tonal noise. Built from commercially available integrated circuits, the periodic inductance is relatively simple to construct and scalable to large unit cell arrays. The implications of this work may extend to several fields in smart materials for achieving tunable control of energy harvesters, elastic waveguides, and vibration absorbers.

Presenting Author: Joshua Dupont University of Connecticut

Presenting Author Biography: Joshua Dupont received his B.S. degrees in mechanical and electrical engineering from the University of Connecticut, Storrs, CT, in 2020. He is currently working on a Ph.D. degree in mechanical engineering at the University of Connecticut.

He is currently a Graduate Research Assistant with the University of Connecticut Department of Mechanical Engineering in Storrs, CT. He is a recipient of the Nation Science Foundation’s 2021 Graduate Research Fellowship Program (GRFP) and conducts his research in the University of Connecticut’s Dynamics Sensing and Controls Laboratory. His research interests include elastic metamaterials, waveguiding, vibration isolation, and energy harvesting.

Authors:

Joshua Dupont
Ting Wang
Jiong Tang