[Paper Review] Cloaking laminate design based on GPT-vanishing structures

Eleanor Gemida, Mikyoung Lim|arXiv (Cornell University)|Jan 25, 2026

Metamaterials and Metasurfaces Applications0 citations

TL;DR

Proposes a near-cloaking laminate design using GPT-vanishing multi-coated structures to achieve enhanced invisibility with isotropic layers and coarser microscale. The approach yields an invisibility order of rho^{d+2N} and allows larger inclusions while maintaining rho^{d} cloaking.

ABSTRACT

We propose a near-cloaking design which is a lamination of a finite number of layers of isotropic materials. The proposed design is an approximation of a cloaking material obtained by pushing forward a multi-coated structure for which the coating cancels the generalized polarization tensors (GPTs) up to several leading orders. The enhanced cloaking effect achieved by the GPT-vanishing structure permits a coarser microscale requirement and reduces the contrast in the constituent isotropic materials, thereby improving constructibility of cloaking laminates compared with designs based on a non-coated structure.

Motivation & Objective

• Motivate and enable practical near-cloaking by replacing anisotropic cloaks with isotropic lamination.
• Leverage GPT-vanishing coatings to cancel leading GPTs and boost invisibility.
• Use homogenization to realize target anisotropic cloaking as a finite-scale laminate.
• Reduce required microscale contrast to improve manufacturability of cloaks.

Proposed method

• Construct a radial laminate in the annulus B_{3/4} /2 with a GPT-vanishing coating embedded in B_{2\u2212\rho}\setminus B_{\rho}.
• Choose coating conductivities to cancel leading GPTs up to order N (GPT-vanishing structure).
• Apply the blow-up transformation to map the GPT-vanishing structure into a cloaking device while preserving the outer boundary.
• Model the cloak as a locally isotropic, multi-layer medium realized by a finite number of isotropic materials.
• Derive a homogenization-based error estimate showing the cloak approximates the target anisotropic cloak with controlled error.

Experimental results

Research questions

• RQ1 How can GPT-vanishing structures be integrated into laminated isotropic configurations to approximate cloaking?
• RQ2 What is the effect of GPT-vanishing order N on the invisibility level and required microscale?
• RQ3 How does homogenization quantify the error between the laminate cloak and the ideal anisotropic cloak?
• RQ4 What are practical parameter choices (layer conductivities, radii, laminations scale) that achieve rho^{d} to rho^{d+2N} cloaking in 2D/3D?
• RQ5 Can the designed laminate cloak tolerate inclusions with arbitrary conductivity within the cloaked region while preserving invisibility level?

Key findings

• A GPT-vanishing multi-coating combined with homogenization yields near-cloaking with invisibility order rho^{d+2N}.
• The pre-transformation inclusion size can be increased to rho^{d/(d+2N)} without losing the higher invisibility order.
• The laminate uses isotropic materials and coarser microscale, improving practical constructibility compared with non-coated structures.
• The enhanced cloaking effect allows a larger inclusion while maintaining rho^{d} cloaking prior to the GPT-vanishing enhancement.
• A rigorous estimate bounds the difference between the cloak DtN map and the homogeneous background DtN map by C rho^{d}.