Conformal cubical 3D transformation-based metamaterial invisibility cloak

Area of Science:

• Electromagnetics and Metamaterials
• Computational Physics
• Applied Mathematics

Background:

• Metamaterial cloaks enable invisibility by guiding electromagnetic waves around an object.
• Previous cloaking designs often lack conformal shapes or require mesh discretization, limiting practical application.
• Accurate full-wave analysis of complex metamaterial structures is computationally intensive.

Purpose of the Study:

• To present and verify a conformal cubical transformation-based metamaterial invisibility cloak.
• To demonstrate a novel numerical technique for analyzing such cloaks without discretizing material profiles.
• To explore the applicability of the methodology for developing advanced perfectly matched layers.

Main Methods:

• A conformal cubical transformation-based metamaterial cloak was designed.
• A rigorous full-wave numerical technique using higher-order, large-domain finite element method (FEM) was employed.
• Anisotropic, continuously inhomogeneous generalized hexahedral finite elements were utilized, avoiding discretization of permittivity and permeability profiles.

Main Results:

• The invisibility cloak was successfully verified in both near and far fields.
• The analysis using the presented FEM approach required approximately 30 times fewer unknowns compared to commercial software.
• This represents the first conformal cubical cloak and the first full-wave computational characterization of a cloaking structure with sharp edges.

Conclusions:

• The developed conformal cubical cloak is a significant advancement in transformation optics.
• The presented higher-order FEM methodology offers a highly efficient and accurate approach for analyzing complex metamaterials.
• The methodology holds potential for the development of conformal, transformation-based perfectly matched layers for electromagnetic wave absorption.