New Sensing and Radar Absorbing Laminate Combining Structural Damage Detection and Electromagnetic Wave Absorption Properties

Abstract

Within the paradigm of smart mobility, the development of innovative materials aimed at improving resilience against structural failure in lightweight vehicles and electromagnetic interferences (EMI) due to wireless communications in guidance systems is of crucial relevance to improve safety, sustainability, and reliability in both aeronautical and automotive applications. In particular, the integration of intelligent structural health monitoring and electromagnetic (EM) shielding systems with radio frequency absorbing properties into a polymer composite laminate is still a challenge. In this paper, we present an innovative system consisting of a multi-layered thin panel which integrates nanostructured coatings to combine EM disturbance suppression and low-energy impact monitoring ability. Specifically, it is composed of a stack of dielectric and conductive layers constituting the sensing and EM-absorbing laminate (SEAL). The conductive layers are made of a polyurethane paint filled with graphene nanoplatelets (GNPs) at different concentrations to tailor the effective electrical conductivity and the functionality of the material. Basically, the panel includes a piezoresistive grid, obtained by selectively spraying onto mylar a low-conductive paint with 4.5 wt.% of GNPs and an EM-absorbing lossy sheet made of the same polyurethane paint but properly modified with a higher weight fraction (8 wt.%) of graphene. The responses of the grid’s strain sensors were analyzed through quasi-static mechanical bending tests, whereas the absorbing properties were evaluated through free-space and waveguide-based measurement techniques in the X, Ku, K, and Ka bands. The experimental results were also validated by numerical simulations.

Enhancing the microwave absorption performance of graphite/Al2O3 composites through manipulating sheet resistance

“…However, the propagation of electromagnetic waves also brings about some hidden problems and dangers, such as electromagnetic wave radiation pollution and electromagnetic wave leakage. [1][2][3][4] Electromagnetic wave absorbers are materials that can effectively absorb electromagnetic waves within a specific frequency range and convert them into thermal energy. They can reduce the reflectivity and transmissivity of electromagnetic waves, thereby reducing the radar cross section of the target.…”

“…In recent years, with the continuous development of wireless communication, radar detection, radio measurement, and other technologies, wireless transmission of electromagnetic waves has become an important way in human life. However, the propagation of electromagnetic waves also brings about some hidden problems and dangers, such as electromagnetic wave radiation pollution and electromagnetic wave leakage 1–4 . Electromagnetic wave absorbers are materials that can effectively absorb electromagnetic waves within a specific frequency range and convert them into thermal energy.…”

Temperature-Controlled and Adjustable Terahertz Device Based on Vanadium Dioxide

“…It has the characteristics of simple structure, high absorptivity, thin thickness, and frequency selectivity. It has great applications in the fields of electromagnetic stealth [8], electromagnetic detection [9,10], biological detection [11], and sensing [12][13][14][15]. However, most metamaterial absorbers only work in a single wave band, with narrow absorption bandwidth, and are unable to achieve dynamic adjustment of absorption efficiency, which has great limitations and cannot be widely used [16][17][18][19].…”