Elastic Polarization Control

Elastic metamaterials have long offered a means to control the propagation of elastic waves, much like optical metamaterials manipulate light. However, conventional elastic metamaterials primarily modify wave velocity or direction without directly addressing polarization selectivity—the ability to isolate longitudinal and transverse motion components in solids. This limitation has hindered precise control over how elastic energy propagates through complex structures.

This study introduces a Single Polarization Elastic Metamaterial (SPEM) that fundamentally overcomes this limitation by enabling polarization-selective transmission of elastic waves. The proposed design incorporates orthogonally oriented mass–spring resonators that act as bidirectional polarization filters. Each resonator predominantly interacts with a specific displacement direction, allowing one polarization mode to propagate while effectively suppressing the orthogonal one.

The polarization-resolved dispersion surfaces reveal distinct propagation branches corresponding to each elastic polarization, and finite element simulations confirm the selective transmission behavior. Within the designed frequency range, one polarization mode is clearly transmitted while the other is strongly attenuated—realizing a form of elastic polarization filtering analogous to the function of optical polarizers in photonics.