Double negative elastic metamaterial design through electrical-mechanical circuit analogies

Area of Science:

• Solid-state physics
• Materials science
• Acoustics

Background:

• Existing elastic metamaterials with negative bulk modulus and density often exhibit narrow operational bandwidths due to reliance on resonators.
• Applications like invisibility cloaks and sub-wavelength lenses necessitate elastic metamaterials with wider bandwidths for practical implementation.

Purpose of the Study:

• To propose a novel elastic metamaterial design that achieves simultaneously double negative properties (negative bulk modulus and density) without the bandwidth limitations of prior designs.
• To leverage electrical-mechanical circuit analogies and established electromagnetic metamaterial designs for a new elastic metamaterial concept.

Main Methods:

• Adaptation of a well-known electromagnetic metamaterial design.
• Application of electrical-mechanical circuit analogies to elastic systems.
• Theoretical analysis of the resulting elastic metamaterial properties.

Main Results:

• A simultaneously double negative elastic metamaterial design is proposed.
• The new design overcomes the narrow bandwidth constraints inherent in resonator-based approaches.
• An unusual property observed is an effective wavelength that approaches infinity as frequency increases.

Conclusions:

• The proposed elastic metamaterial design offers a pathway to broader practical applications by overcoming bandwidth limitations.
• This work demonstrates the successful translation of electromagnetic metamaterial concepts to elastic systems.
• The asymptotic behavior of the effective wavelength presents unique physical characteristics for further investigation.