Metamaterials beyond electromagnetism.

Area of Science:

• Physics and Materials Science
• Engineering

Background:

• Metamaterials are artificial structures with properties not found in nature.
• Often associated with optical phenomena like negative refractive index and cloaking.
• The metamaterial concept applies broadly across physics and engineering disciplines.

Purpose of the Study:

• To review the fundamental concepts of metamaterials.
• To explore analogies and differences with electromagnetic metamaterials.
• To provide an experimentalist's overview of current theory and experiments.

Main Methods:

• Review of existing literature and experimental data.
• Analysis of homogeneous and inhomogeneous metamaterial designs.
• Exploration of coordinate-transformation-based approaches.

Main Results:

• Metamaterials have diverse applications in thermodynamics, mechanics (acoustics, elastodynamics, etc.), and quantum mechanics.
• Examples include thermal cloaks, acoustic cloaks, auxetic mechanical metamaterials, and seismic metamaterials.
• Experimental advancements cover various metamaterial types and functionalities.

Conclusions:

• The metamaterial concept offers a unified framework for designing materials with exotic properties across multiple fields.
• Coordinate-transformation techniques are crucial for designing advanced metamaterial architectures.
• The field is rapidly evolving with significant theoretical and experimental progress.