Trampoline metamaterial: Local resonance enhancement by springboards

TL;DR

This paper introduces the trampoline metamaterial, where pillars on a patterned plate act as springboards, significantly amplifying local resonance and enlarging subwavelength band gaps, enabling broader frequency control.

Contribution

It demonstrates a novel trampoline effect in elastic metamaterials, enhancing local resonance and expanding subwavelength band gaps through structural design.

Findings

Subwavelength band gaps increase up to 4 times in size.

Solid regions act as springboards for resonance amplification.

Broad frequency ranges for metamaterial properties are achieved.

Abstract

We investigate the dispersion characteristics of locally resonant elastic metamaterials formed by the erection of pillars on the solid regions in a plate patterned by a periodic array of holes. We show that these solid regions effectively act as springboards leading to an enhanced resonance behavior by the pillars when compared to the nominal case of pillars with no holes. This local resonance amplification phenomenon, which we define as the "trampoline effect", is shown to cause subwavelength band gaps to increase in size by up to a factor of 4. This outcome facilitates the utilization of subwavelength metamaterial properties over exceedingly broad frequency ranges.