Session: VIB-03-01: Dynamics & Waves in Solids and Metamaterials I

Paper Number: 89745

89745 - Dispersion Morphing in Highly-Reconfigurable Rotator Lattices 

We investigate wave propagation in in-plane rotator lattices and demonstrate dispersion morphing and extreme acoustoelastic effects via analytical and numerical means. By changing the angle of the rotator arms attaching the elastic linkage between adjacent rotators, we show that the band structure may morph from a positive/negative-group-velocity passband into a flat band across the whole wavenumber space, and then into a negative/positive-group-velocity passband. A similar process can also occur at certain fixed arm angles when the lattice constant changes, which one may interpret as stretching or compressing the structure along the lattice directions as an analog to the acoustoelastic effect. We analytically investigate both processes and provide closed-form expressions for the occurrence of flat bands, which indicates the transition of the passband property. Further, we explore a chiral rotator lattice design where the oscillation equilibrium position for each rotator may shift upon the change of the lattice constant. This design has a unique advantage that the morphed passband maintains around the same frequency range such that a signal may stay propagating during the process of dispersion morphing. At the end, we present numerical simulations for three potential applications utilizing the aforementioned findings. In these applications, both static and dynamic lattice stretching are considered, resulting in on-demand bi-directional wave-guiding, refraction bending, and time-modulated amplifying. The numerical simulations reach a high-degree of agreement with the theory and yield promising results that may inspire next-generation reconfigurable metamaterials.

Presenting Author: Lezheng Fang Georgia Institute of Technology

Presenting Author Biography: Lezheng Fang is a 4th year Ph.D. student at Georgia Tech. His research focuses on nonlinear periodic structures and metamaterials exhibiting non-reciprocity, negative refractive index, and reconfigurable dispersions.

Authors:

Lezheng Fang Georgia Institute of Technology
Michael Leamy Georgia Institute of Technology