Multilayer cylindrical invisibility cloak at microwave frequencies built from polymer and carbon nanotubes

Abstract

We present a multilayered invisibility cloak effective at microwave frequencies based on carbon nanotubes (CNT) and polymer foam. The structure deflects transverse magnetic (TM) waves at 6GHz to reconstruct the incoming wave front beyond an obstacle. This is achieved with the help of nested cylindrical arrangements of anisotropic conductive films and insulating foam spacers, which provide the correct gradient of effective permittivity in the radial direction. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:65–69, 2017

Smart Nanocomposites for Nanosecond Signal Control: The Nano4waves Approach

“…Periodic or gradient structuration of isotropic or pre-oriented nanocomposites has been achieved by stacking multiple layers of films ( Figure 2a) alternating insulating dielectric polymer and conductive nanocomposite films. Stacks arranged in a gradient of conductivity are predicted to favor the penetration and progressive absorption of electromagnetic waves inside a nanocomposite material (Figure 2b), which has been confirmed experimentally [5]. A simple method based on chain matrix conversion [11] simulates the scattering parameters (S-parameters) and absorption index if the physical parameters of each layer are known.…”

“…[1], artificial or composite materials dedicated to the control of wireless propagation of signals (popularized over the last decade under the term "metamaterials" in the scientific community) are multi-functional materials tailored to display electromagnetic (EM) properties not found in nature, through a nonconventional modification of their macroscopic effective permittivity and/or permeability, sometimes reaching negative values [2]. Superlensing beyond the diffraction limit [3], invisible cloaking of objects [4,5], left-handed propagation reducing the size of devices to one tenth of their operating wavelength [6], frequency selective surface (FSS) [7,8] or electromagnetic bandgap (EBG) structures [9][10][11][12] are some of the outstanding developments in progress over various frequency ranges, going from GHz to optics.…”