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The type of multi-component fillers and their spatial distribution in conductive polymer-based composites greatly influenced their electrical properties, electromagnetic shielding efficiency (SE), and absorption capability, which require a deep understanding of how these properties improve with changes in the phase composition, content, and distribution of these fillers in the composite. In this study, three-phase polymer composite materials (CMs) with random (epoxy-based) and segregated (polyethylene-based) distribution of nanocarbon (graphite nanoplatelets GNP and carbon nanotubes CNTs) and magnetic (Fe and Co3O4) fillers have been developed. It was found that permittivity ε r ′ in the frequency range (40–60 GHz) increases sufficiently with the nanocarbon content and their values are slightly higher for random GNP-filled CMs (ε r ′ = 10 – 15 for 3–5 wt. % GNP) compared to CNT-filled CMs and much higher compared to segregated CMs (ε r ′ = 4 – 7 for 3–5 wt. % of nanocarbon). Dielectric loss tangent tan δ is increased with the nanocarbon content (especially for Fe-filled CMs) and sufficiently higher in segregated CMs compared to similar random composites. These enhanced tan δ values correlate with higher electromagnetic shielding efficiency due to absorption of segregated nanocarbon/magnetic/polyethylene CMs, for example, SEAd ≈ 18–23 dB/mm for 5 wt. %GNP. The most preferable for microwave absorption are random and segregated CMs with 2–3 wt. % GNP/30 wt. % magnetic filler: RLmin = −(27–35) dB, effective absorption bandwidth (EAB) Δ f 10 dB = 11.5 – 12.5 GHz at a sample thickness of 0.5–0.7 mm. In CNT-based segregated CMs, | R L min | and EAB values are lower compared with GNP-based CMs. The ability to manipulate these characteristics is important for obtaining good shielding and absorptive properties in the microwave range of electromagnetic radiation. [ABSTRACT FROM AUTHOR]

Electromagnetic shielding is a critical function in various technologies, which is ideally achieved using a metal that reflects all incident radiation below its plasma frequency. Using high-resolution finite difference frequency domain simulations at microwave/RF frequencies, we show that the same efficacy can be achieved using a disordered collection of metal nanoparticles embedded in a flexible material. The mechanism underlying the reflection in the composite material is wave localization, disallowing the propagation of radiation up to the plasma frequency of the metal that constitutes the particles. We realize such a biopolymer composite using DNA–CTMA (deoxyribonucleic acid–cetyltrimethylammonium complex) as a support structure for Ag nanoparticles. This biopolymer composite exhibits an extremely high shielding effectiveness, close to that of a metal slab, because of Anderson localization of the electromagnetic waves. [ABSTRACT FROM AUTHOR]

[Display omitted] The challenge of achieving high-performance electromagnetic interference (EMI) shielding films, which focuses on electromagnetic waves absorption while maintaining thin thickness, is a crucial endeavor in contemporary electronic device advancement. In this study, we have successfully engineered hybrid films based on MXene nanosheets and Fe 3 O 4 nanoparticles, featuring intricate electric–magnetic dual-gradient structures. Through the collaborative influence of a unique dual-gradient structure equipped with transition and reflection layers, these hybrid films demonstrate favorable impedance matching, abundant loss mechanisms (Ohmic loss, interfacial polarization and magnetic loss), and an "absorb-reflect-reabsorb" process to achieve absorption-dominated EMI shielding capability. Compared with the single conductive gradient structure, the dual-gradient structure effectively enhances the absorption intensity per unit thickness, and thus reduces the thickness of the film. The optimized film demonstrates a remarkable EMI shielding effectiveness (SE) of 49.98 dB alongside an enhanced absorption coefficient (A) of 0.51 with a thickness of only 180 μm. The thin films with a dual-gradient structure hold promise for crafting absorption-dominated electromagnetic shielding materials, highlighting the potential for advanced electromagnetic protection solutions. [ABSTRACT FROM AUTHOR]

Expanded graphite (EG) is a desired filler for electrothermal and electromagnetic interference (EMI) shielding because of its easy access, low‐cost, lightweight, high conductivity, and heat sensitivity. Herein, fluffy EG was prepared from natural flake graphite (NFG) by a simple expansive technology and subsequently heat treatment at 800°C for 2.0 h in 5% Ar/H2 atmosphere. EG/silicone films with a filling ratio of 15 wt% were obtained via hot‐pressing, which exhibited sensitive electrothermal and excellent EMI shielding performances. When the applied voltages were 5.0, 10.0, and 15.0 V, the steady‐state temperatures were 54.0, 136.5, and 237.8°C in the 30s, respectively. Meanwhile, their average EMI shielding efficiency was greater than 20 dB in 2–18 GHz at 0.84 mm, which was 6.3 times as much as NFG/silicone film. Therefore, this study offers a simple and effective strategy for preparing excellent electrothermal‐EMI shielding materials. Highlights: Fluffy EG is prepared by a simple expansive method and treatment at 800°C.EG/silicone films exhibit good electrothermal and EMI shielding performances.Steady temperatures of 55.0/136.5/237.8°C are gotten at 5/10/15 V in 30 s.The EMI shielding efficiency is greater than 20 dB at 0.84 mm.Good properties are due to the EG with high conductivity and fluffy structure. [ABSTRACT FROM AUTHOR]

With the advent of 5G/6G for radar and space communication systems, various millimeter‐wave (MMW) components are rapidly innovated for multi‐functional, higher integrated and miniaturized solutions across diverse industries and applications. Polymer composites‐based additive manufacturing (AM), an advanced manufacturing technique, can manufacture MMW components with high fabrication resolution, intricate structural design, adjustable dielectric properties, and functionally gradient distribution characteristics. This paper outlines the state‐of‐the‐art polymer composite MMW components, their design, and manufacturing techniques. An integrated "material‐structure‐manufacturing‐performance" design conceptual framework of polymer composite MMW components is discussed in terms of material design, structure design, and process design. Moreover, multi‐functional polymer composite MMW structures focus on electromagnetic wave absorption and electromagnetic interference (EMI) shielding functions. Moreover, novel applications of MMW polymer composite components enabled by AM on radar/sensing, communication, enclosure, and miscellaneous applications are discussed. Furthermore, future perspectives and current challenges are identified to provide new insights into multi‐functional 3D‐printed MMW products, exploring new possibilities for next‐generation advanced MMW technology. Highlights: The 3D‐printed MMW components and additive manufacturing are reviewed.The integrated "material‐structure‐manufacturing‐performance" concept is introduced.3D‐printed MMW components are discussed on radar, enclosure, and miscellaneous applications.Future perspectives and challenges of 3D‐printed MMW components are addressed. [ABSTRACT FROM AUTHOR]

In this paper, a frequency selective surface (FSS) for n41, n78, n257, n258, n260, and n261 bands electromagnetic interference (EMI) shielding is proposed using a deep learning method. The size of the FSS unit cell is 4.8 mm (0.071 λ 0 ), where λ 0 is the wavelength corresponding to the cutoff frequency of the −10 dB stopband where the n41 and n78 bands are located. This FSS exhibits three key characteristics. Firstly, it possesses ultrawideband capability, with a stopband frequency range of 23.922–40.023 GHz and a relative bandwidth reaching 50.4%. Secondly, it effectively shields against electromagnetic radiation in multiple 5 G bands, including n41, n78, n257, n258, n260, and n261. Thirdly, it demonstrates high selectivity, with a very narrow transition band of only 0.405 GHz between the passband and the stopband. To validate the designed FSS, a prototype of this structure was first fabricated for experimentation. The experimental results show that the measured S21 is highly consistent with the simulated S21. Secondly, the unit cell array of FSS is placed above the monopole antenna for co-simulation. It can be observed that after placing the FSS, the intensity of electromagnetic radiation propagating in space is significantly reduced by up to more than 90%. Therefore, the proposed FSS can be effectively applied for EMI shielding in 5 G bands. [ABSTRACT FROM AUTHOR]

This study assesses the shielding efficacy of local electromagnetic shield for the thyroid gland. The investigation employed a mechanical model of a thyroid shield gear, integrating it within a high-resolution three-dimensional virtual model (Duke). The simulation environment and biological electromagnetic model were constructed from 1 to 6 GHz, with the Finite-Difference Time-Domain (FDTD) algorithm. The results indicated that the specific absorption rate (SAR) values of the thyroid were significantly elevated under forward irradiation and in the L band (1–2 GHz). In addition, the local electromagnetic shield reduced the SAR values at the thyroid position, with a shielding efficiency ranging from 15 to 40 dB across the evaluated frequency range. Further, the local shielding effectiveness of the thyroid have obvious variety between frequency and polarization. However, the data also indicated a potential increase in SAR values in other tissues, notably the eyes by up to 4 dB. The study determines that local electromagnetic shields markedly reduce radiofrequency radiation to the thyroid, necessitating a balanced design approach that accounts for both protective benefits and side effects on other tissues. The method and result provide a new perspective and quantitative data for thyroid protection, which has important guiding significance for the design and practical application of electromagnetic protection products. [ABSTRACT FROM AUTHOR]

ABSTRACT The recent development of wireless communication technology has increased the risk of electronic equipment malfunctions and information leaks. To address this issue, we developed and evaluated a lightweight and flexible electromagnetic shielding material that can be applied to wearable devices by combining carbon nanotubes and elastomer materials. [ABSTRACT FROM AUTHOR]

With the development of nanotechnology, nano-functional units of different dimensions, morphologies, and sizes exhibit the potential for efficient microwave absorption (MA) performance. However, the multi-unit coupling enhancement mechanism triggered by the alignment and orientation of nano-functional units has been neglected, hindering the further development of microwave absorbing materials (MAMs). In this paper, two typical ZIF-derived nanomaterials are self-assembled into two-dimensional ordered polyhedral superstructures by the simple ice template method. The nano-functional units exhibit distinctive dielectric-sensitive behaviors after self-assembling into two-dimensional ordered arrays. The modified 2D ordered polyhedral superstructures not only inherit the atomic-level doping and well-designed shell structure, but also further amplify the loss properties to realize the multi-scale modulated MA response. Satisfactory MA performance in C, X and Ku bands is finally achieved. In particular, the ultra-broadband microwave absorption bandwidth (EAB) of 6.41 GHz is realized at 1.82 mm thickness. Our work demonstrates the two-dimensional ordered array-induced multiscale polarization behavior, providing a direction to fully utilize the potential of wave-absorbing functional units. This work delves into the effects of orientation of ordered nano-units in 2D arrays on electromagnetic shielding. Polyhedral superstructures allow for good performance in the C, X, and Ku bands, with a bandwidth of 6.41 GHz at 1.82 mm thickness. [ABSTRACT FROM AUTHOR]

Thin films of polyaniline/polyvinyl chloride (PANI/PVC) composites synthesized and irradiated with a nickel ion (Ni7+) beam using flux of 3.125 × 109 particles/cm2/s and fluence ranging between 3 × 1011 and 1 × 1013 particles/cm2 were investigated with respect to their optical, structural, and electrical properties. The photoluminescence (PL) analysis showed that swift heavy ion (SHI) irradiation caused the creation of new color centers, which were diminished at greater fluence. With irradiation, both the direct and indirect band gaps decreased, making the materials more conducive to conduction. However, the direct band gap was smaller than the indirect band gap. Fourier transform infrared (FTIR) analysis showed that the aromatic nature of PANI was not disturbed by SHI irradiation. The variation in capacitance with frequency indicated that the material can be used for electromagnetic interference (EMI) shielding, and the shielding properties are modified by ion irradiation. Scanning electron microscopy (SEM) analysis revealed that irradiation of the polymer with Ni7+ leads to chain scissoring and cluster formation, whereas at higher fluence, smaller parts are rearranged to form micro-clusters. [ABSTRACT FROM AUTHOR]

Hydrogels, featuring high flexibility and stretchability, have intense wave‐matter interaction in the terahertz (THz) band and high transparency in the visible light band, making them promising materials for transparent THz absorbers in the optical windows of THz devices. However, conventional hydrogels suffer from poor environmental stability, as water evaporation or freezing at subzero temperatures weakens their THz absorption and visible transmittance. Here, An ion‐rich hydrogel film is presented to concurrently boost the THz wave‐ion and intermolecular interactions. The boosted interactions increase the ionic conduction loss and improve the antidrying and antifreezing performance. As a result, with polydimethylsiloxane (PDMS) as the encapsulation layer and antireflection layer, the flexible ionic‐hydrogel‐based THz absorber shows a high maximum reflection loss (RL) of 86.51 dB in the 0.5–4.5 THz range (100% qualified bandwidth) and a high average visible transmittance of 90.87% with a thickness of only 300 µm. Moreover, it still possesses a high average RL of 39.35 dB after 80 days at room temperature and a high average electromagnetic interference shielding efficiency (EMI SE) of 42.30 dB at −10 °C. This work demonstrates the feasibility of transparent ionic THz absorbers, offering inspiration for future ionic THz device designs. [ABSTRACT FROM AUTHOR]

Highlights A simple strategy of hot imprinting was proposed to construct a densified filler network for the preparation of electrospun polyvinylidene fluoride (PVDF) composite film with high thermal conductivity and electromagnetic shielding performance. First, continuous imprints were obtained by hot pressing on the surface of PVDF fiber film using a metal mesh as a stencil. Magnetic Fe3O4‐modified carbon nanotubes (Fe3O4@CNTs) were then loaded onto the surface of the films using an impregnation method. Finally, the Fe3O4@CNTs/PVDF composite film was fabricated by a three‐layer hot pressing process. The mesh size and filler loading cycles have an important effect on the resulting performance of the composite film. Under the optimal conditions of 1 × 2 mesh size and five loading cycles, the thermal conductivity of the composite film with only 5.16 wt% CNTs content, was 1.91 W/mK, which is an improvement of 51.6% compared to that of the non‐imprinted composite film. The electromagnetic shielding effectiveness of the composite film reached 28.6 dB. This strategy provides a feasible approach for the large‐scale production of high‐performance thermal interface materials. Enhancing continuous filler network in PVDF composite film by hot imprinting. Developing carbon nanotube and Fe3O4 hybrid fillers with a heterogeneous structure. Achieving significant improvements in TC and EMI SE of the composite film. Offering large‐scale production methods of high‐performance thermal interface materials. [ABSTRACT FROM AUTHOR]

Flexible sensors hold significant promise for wearable monitoring and rehabilitation training applications. However, current flexible strain sensors struggle to compatible their sensing performance and fabrication with textile substrate and weaving technologies, which limits the practical applications of flexible sensors in commercial markets for electronic wearables. Differing from traditional strategies that rely on sophisticated construction of functional materials, leveraging industrial braiding, and weaving technologies, an all‐textile‐based pseudo‐triaxial mechanosensory textile (PTMT) is designed by engineering the wrapping pattern, yarn twist, and fabric architecture. The switchable hierarchically‐structured morphing of the PTMT enables an ultra‐wide strain detection range (up to 140%) along with desirable sensitivity. Moreover, the PTMT shows outstanding air permeability (1915 mm s−1), moisture permeability (1922 g m−2 h−1), high washability, and electromagnetic interference shielding (20.25 dB). The potential applications of PTMT are also demonstrated, such as in simulating fetal‐movement in pregnant women, proving its effectiveness in fetal‐movement health monitoring. Furthermore, by integrating the PTMT into shoe vamps and combining it with machine learning algorithms (CNN, RF, and PSO‐SVM), it is proved that PSO‐SVM outperformed CNN and RF in accuracy and stability, achieving a combined recognition accuracy of 95.42%. [ABSTRACT FROM AUTHOR]

2D materials and their composites with electromagnetic properties are becoming increasingly popular. Obtaining insight into the nature of electromagnetic (EM) response manipulation is imperative to guide scientific research and technological exploitation at such a critical time. From this perspective, the dielectric genes of 2D material hybrids have been highlighted based on the recent literature. This endows an unlimited possibility of manipulating the EM response, even at elevated temperatures. The definitions and criteria of dielectric genes toward 2D material hybrids and composites are systematically clarified and summarized. The dielectric gene categories are successfully discriminated, including the conduction networks, intrinsic defects, impurity defects, and interfaces in the composite, and their temperature evolution is revealed in detail. More importantly, tuning strategies for microwave absorption, electromagnetic shielding effectiveness, and expanded electromagnetic functions are thoroughly discussed. Finally, significant predictions are provided for multispectral electromagnetic functions, and future applications of multifunctional exploration are anticipated. Dielectric genes will open an unexpected horizon for advanced functional materials in the coming 5G/6G age, providing a significant boost to promoting environmental electromagnetic protection, electromagnetic devices, and next‐generation smart devices. [ABSTRACT FROM AUTHOR]

Combining the merits of battery and supercapacitor into a single device represents a major scientific and technological challenge. From a design perspective, electrode material plays a key role in the device and the fundamental difficulty lies in incorporating a high density of active sites into a stable material with excellent charge transfer kinetics. Here, the synthesis is reported of a nearly full‐oxygen‐functionalized 2D conductive transition metal carbide (Ti3C2Oy) with ultrahigh density of Ti─O/═O redox‐active sites by nucleophilic substitution and in situ oxidation under the presence of a proper electrophilic reagent (K+). The fabricated electrode delivered exceptionally high gravimetric and volumetric capacitance (1,082 F g−1 and 3,182 F cm−3 in a potential window of 0.85 V, approximating the theoretical capacity of many transition metal oxides), fast charging/discharging in tens of seconds across a wide range of temperature (−70 to 60 °C), and excellent structural and chemical stability. These promising results provide avenues for the development of high‐energy, high‐power storage devices as well as electromagnetic shielding, and electronic and optoelectronic devices. [ABSTRACT FROM AUTHOR]

Developing high‐performance multifunctional materials is critical for advancing integrated electronics and telecommunication systems. This study presents super‐strong, ultra‐flexible, conductive nanopapers featuring layered architectures, achieved by incorporating cellulose nanofibril‐modified MXene (CM9) and cellulose nanocrystals (CNCs) into an aramid nanofiber (ANF) network and silver nanowire (AgNW) framework through a multi‐stage vacuum filtration. The resulting nanopapers achieve remarkable tensile strength (701.82 MPa), outstanding toughness (101.86 MJ m−3), and a specific tensile strength of 486.67 MPa·g−1·cm3, notably outperforming that of titanium alloys (257 MPa·g−1·cm3). In addition to their mechanical properties, the nanopapers exhibit high electrical conductivity (1139.48 S cm−1), resulting in superior electromagnetic interference (EMI) shielding effectiveness (EMI SE) of 62.28 dB with an ultra‐thin profile of 22.38 µm. The nanopapers also demonstrate excellent durability, maintaining an EMI SE of 60.16 dB after 20% stretching and 57.15 dB after 20 000 folding cycles, along with a tensile strength of 685.59 MPa. Additionally, they exhibit efficient photothermal conversion and electrothermal deicing capabilities, reaching a maximum temperature of 242.78 °C under applied voltage. With their unique combination of mechanical robustness, conductivity, and thermal performance, these nanopapers show great potential for next‐generation electronics, flexible displays, and high‐performance thermal management systems. [ABSTRACT FROM AUTHOR]

The development of electronic fuze has placed higher demands on encapsulation resins, which are required to provide not only insulation and protection, but also higher impact resistance and good electromagnetic shielding performance. A new composite material consisting of hollow glass microspheres (HGM) and modified epoxy resin was developed. This material exhibits significant electromagnetic shielding capabilities for terahertz (THz) waves, as well as superior impact energy absorption properties. Bisphenol A‐type epoxy resin (E‐44) was modified using Al(OH)3, red phosphorus, carbon black, and SiO2, and the material properties were optimized by adjusting the HGM content. The electromagnetic shielding effectiveness and impact energy absorption of the composite material in the THz band were comprehensively tested using THz time‐domain spectroscopy and split Hopkinson pressure bar testing systems. Additionally, a comprehensive evaluation of the mechanical and dielectric properties, thermal conductivity, and thermal stability of the material was conducted. The results showed that the electromagnetic shielding effect of 60 vol.% HGM hybrid‐modified resins was the best, reaching 43.78 dB. The 20 vol.% HGM hybrid‐modified resins not only has a specific absorption energy of 18.51 J/cm3, but also has the best overall performance. This work has advanced the design and development of multifunctional and impact‐resistant potting epoxy resins. [ABSTRACT FROM AUTHOR]

Polymer‐based composites that exhibit a unique nonlinear response to high‐power electric fields have the potential to serve as intelligent electromagnetic shielding materials. The optimization of switching fields (Eb) and nonlinear coefficient (α) of polymer‐based composites is of great interests for nonlinear conductive performance. Based on literature data, the prediction models for Eb and α are first successfully established using machine learning (ML) methods. A stacking ensemble learning (SEL) strategy was used to combine five base machine learning models, showing superior predictive performance. The research focuses on the effect of key process parameters on nonlinear conducting composites. The feature importance analysis shows that the nonlinear properties of the composites are considerably impacted by the mass fraction, filler size, and sample thickness. The parameter optimization method to improve the performance of the composites was explored by using partial dependence plots analysis. By measuring the nonlinear response of CNT/ZnO composites under high electric fields, the effectiveness of the optimization strategy is experimentally verified. This work establishes the intrinsic relationship between composition and performance, which is helpful in designing intelligent self‐adaptive electromagnetic shielding for switchable electronic devices. Highlights: Prediction models for Eb and α using machine learning.Stacking ensemble learning for superior predictive performanceFocuses on the effect of key process parameters on performance.Optimization strategy validated through experimental testing. [ABSTRACT FROM AUTHOR]

This study details the fabrication of a hybrid fabric structure achieved through the utilization of copper-cotton core-spun yarns and a streamlined dip-coating method for the coating of MXene sheets. This fabrication approach results in a substantial enhancement in electromagnetic interference shielding efficiency (EMI SE) in the X-band frequency (8.2-12.4 GHz) while significantly reducing the required number of MXene coating steps. The textile samples fabricated with 0.08 mm diameter copper core filaments and a knitting density of 12 gauge (needle/inch) exhibit a peak EMI SE of 43.9 dB following three MXene coating cycles, utilizing a 1×1 Rib knit pattern. In comparison, employing a Full Milano knit pattern results in an improved EMI SE, reaching up to 45.2 dB. These findings elucidate the substantial impact of knit structure and the effective MXene coating process on improving the EMI SE for hybrid textiles. [ABSTRACT FROM AUTHOR]

Technological development has led to the need for materials able to block electromagnetic waves (EMWs) emitted from various devices. EMWs could negatively affect the working performance and lifetime of multiple instruments and measuring devices. New EMW shielding materials are being developed, while among nanomaterials, graphene-based composites have shown promising features. Herein, we have produced graphene oxide (GO), silver nanowires (AgNWs) composites, by varying the mass ratios of each component. UV-Vis, infrared, Raman spectroscopies, and thermogravimetric analysis proved the establishment of the interactions between them. For the first time, the strength and the nature of the interaction between GO sheets with various levels of oxidation and AgNWs were investigated using density function theory (DFT). The interaction energy between ideal graphene and AgNWs was calculated to be −48.9 kcal/mol, while for AgNWs and GO, this energy is almost doubled at −81.9 kcal/mol. The DFT results confirmed the interfacial polarization at the heterointerface via charge transfer and accumulation at the interface, improving the efficacy of EMW shielding. Our results indicated that AgNWs create a compact complex with GO due to charge transfer between them. Charge redistributions in GO-AgNWs composites resulted in an improved ability of the composite to block EMWs compared to GO alone. [ABSTRACT FROM AUTHOR]

In this paper, electromagnetic shielding properties of reduced graphene oxide (RGO) composites with cerium-doped lanthanum ferrite, La 0.9 Ce 0.1 FeO 3 (LCFO), are studied. The synthesis procedure adopted is incipient wetness impregnation with SBA-15 as a template for LCFO and modified Hummer's method for graphene oxide (GO). The composites are synthesized by in-situ reduction of GO in the presence of LCFO, which acts as a magnetic filler in the weight ratios 1:0, 1:1, 2:1, 3:1 and 1:2 of LCFO and GO. X-ray diffraction (XRD), Fourier Transform Infrared spectroscopy (FT-IR), Field emission scanning electron microscopy (FE-SEM) and nitrogen absorption/desorption isotherm are used to investigate the structural properties. Vector network analyzer (VNA) is used to ascertain the shielding and dielectric properties. The La 0.9 Ce 0.1 FeO 3 -reduced graphene oxide (LCFG31) composite shows appreciable electrical conductivity of 81.43 S/m and an effective BET surface area value of 23.93 m2g-1. It attenuates >99.99 % of electromagnetic waves, and a shielding effectiveness (SE) value of 41.82 dB at a thickness of 2.36 mm in the Ku frequency band (12.4–18 GHz) has been achieved. The heterogeneous interfaces in the composite structure result in orientational and space charge polarization. The inclusion of magnetic ferrite as filler in composite incurs eddy current loss and magnetic losses. All these factors collectively make the composite material a good choice for electromagnetic shielding which can be further used for commercial applications. [ABSTRACT FROM AUTHOR]

Flexible paper‐based electronics are trending currently for its biodegradability, light weight, and compactness. A flexible film with 10, 20, 30 wt% of BCST‐CNF multiferroic filler is systematically investigated by initially simulating electromagnetic interference (EMI) shielding parameters using CST Studio Suite Software. Nicolson–Ross wire algorithm is used to estimate the EM parameters of PVDF/(Ba0.945Ca0.055Sn0.07Ti0.93)O3–Co0.9Ni0.1Fe2O4)(BCST‐CNF) (PBC) films. By adaption of PBC on mulberry paper, the shielding effect of the screen‐printed EMI shielding material with 30 wt% of multiferroic filler reveals over 65.24 dB, which is the highest value of shielding effect for X‐band compared to other tested films. Moreover, it shows enhanced microwave absorption of 63.48 dB. This study opens up an effective avenue for designing strong microwave absorption materials to satisfy the increasingly demanding requirements of advanced and integrated electronics. [ABSTRACT FROM AUTHOR]

Multifunctional electromagnetic wave (EMW) absorbing materials are attracting attention because of their potential applications in medical, livelihood, and military. In this study, a pomegranate‐like nanolayer featuring a core‐shell architecture (PNCS) is prepared using a confinement strategy. Introducing metal atoms into this unique pomegranate‐like design (M‐PNCS, M = Mn, Fe, Co, Ni, and Cu) effectively tuned the electromagnetic response and improved the electromagnetic functions. The Mn‐PNCS composite exhibited the highest electromagnetic absorption. Its reflection loss (RL) reached −62.39 dB with an effective absorption bandwidth (EAB) at 1.8 mm of 6.0 GHz. As the charge transport capacity of the Mn‐PNCS increases, its absorption can be transformed into shielding, with a green shielding index of up to 3.54. On this basis, Mn‐PNCS is used to fabricate a multifunctional film and a new design of strain sensor. This multifunctional film integrated electromagnetic absorption, thermal insulation, hydrophobicity, flexibility, and sensing, thus showing potential for use in wearable electromagnetic protective clothing. In addition, the sensors in the simulation design achieved strain sensing through the coupling effect between the Mn‐PNCS patterns. These findings demonstrate that Mn‐PNCS is an excellent multifunctional material with potential applications in the technical fields of EMW absorption, electromagnetic shielding, and wearable devices. [ABSTRACT FROM AUTHOR]

Highlights Electromagnetic shielding properties of conductive polymer composites (CPCs) are dependent on the content of conductive fillers. In this study, electromagnetic shielding effectiveness (EMW SE) of poly(ε‐caprolactone) (PCL) filled with different content of multi‐walled carbon nanotubes (MWCNTs) were prepared to systematically discuss content‐dependent electromagnetic shielding mechanism via a simulation and experimental study. At low MWCNT loadings, the composites have high absorption coefficients because the MWCNT particles are separated by PCL chains. The shielding performance mainly comes from the polarization loss and conduction loss. However, the composites with high content of MWCNT can form conductive networks which leads to high reflection values, suggesting a reflection‐dominant shielding mechanism. In addition, a conductive mesh model is first introduced to simulate the effect of filler loadings on electromagnetic shielding performance. For electrical conductivity, there is no obvious platform being found in the samples at a high content of MWCNTs. The formation of a denser conductive network within the composites reduces inter‐filler gaps and promotes closer contact. However, according to the experimental and simulation results, upon exceeding the percolation threshold of MWCNT loadings, the EM SE value slightly increases leading to a plateau region. The results are ascribed to the formation of stable shielding networks at high content of MWCNTs. The sample has a high absorption coefficient at a low content of MWCNTs. All the samples exhibit a reflection‐dominant shielding mechanism. No obvious platform of conductivity is found at high content of MWCNTs. Obvious platform of EMW SE values is found in the high content of MWCNTs. High EMW SE values for CPC only require relatively dense conductive networks. [ABSTRACT FROM AUTHOR]

Hydrogels/organohydrogels show promise for flexible, intelligent electromagnetic interference (EMI) shielding, yet simultaneously achieving absorption‐dominated shielding performance, excellent mechanical properties and multi‐mode intelligent responsiveness remains challenging. This study presents a microcapacitor network strategy as an alternative to the traditional conductive percolation network for EMI shielding materials. Paraffin‐nanoclay/MXene core‐shell microspheres are uniformly integrated into the hydrogel matrix via in situ polymerization, forming a microcapacitor network where the microsphere shells and hydrogel serve as capacitor plates and dielectric layers, respectively. Microcurrents and interfacial polarization at capacitor plates, along with dipole polarization within dielectric layer, significantly promote EM wave attenuation for absorption‐dominated EMI shielding (absorption coefficient >0.7). Meanwhile, the abundant hydrogen bonds and paraffin phase synergistically enhance mechanical strength (≈0.64 MPa) and stretchability (elongation at break > 1000%). Due to the solid‐liquid phase transition of the paraffin phase in microspheres, organohydrogel exhibits a unique ability to retain high‐temperature shielding performance at room temperature. This feature enhances room‐temperature shielding effectiveness and enables multi‐mode intelligent responsiveness. Under the same room‐temperature deformation mode, it exhibits programmable shielding performance regulation in response to different external stimuli, following room‐temperature changes or simulating high‐temperature changes. [ABSTRACT FROM AUTHOR]

With the rapid development of the electromagnetic (EMI) industry, EMI pollution has become a serious problem. In this work, the effect of filler content on electromagnetic shielding performance was studied by heat-induced polymerization of acrylamide (AM) and gelatin (Gel) to form double-mesh hydrogel (PAM-Gel), and then, different contents of carbon nanotubes (CNTs) and reduced graphene oxide (RGO) were added. Finally, a one-dimensional/two-dimensional (1D/2D) PAM-Gel/CNTs-RGO heterostructured van der Waals hydrogel was prepared by mixing CNTs with RGO. The experimental results showed that compared with PAM-Gel/CNTs hydrogel or PAM-Gel/RGO hydrogel, the mixed PAM-Gel/CNTs-RGO hydrogel showed the best EMI shielding performance. In general, the EMI shielding effect of PAM-Gel/CNTs-RGO-1 : 1 in the X-band with a thickness of 4 mm was as high as 45.14 dB, compressive stress–strain was 18.45 MPa and 95.90%, water content was 75.74%, and conductivity was 1.12 s m−1. [ABSTRACT FROM AUTHOR]

We embedded cobalt ferrite (CoFe 2 O 4 , CFO) nanoparticles on carbon nanotubes (CNTs) through oxidation and wet chemical methods to prepare CNT@CFO. Subsequently, aramid nanofiber (ANF)-reinforced aerogel films CNT@CFO/ANF were prepared by vacuum-assisted filtration and freeze-drying. CNT@CFO is evenly interspersed in the ordered ANF layers, giving the aerogel film excellent flexibility and stretchability. In electromagnetic interference shielding (EMI SE) applications, electromagnetic coupling and rich heterogeneous interfaces alleviate impedance mismatch and improve the attenuation of electromagnetic waves. The CNT@CFO/ANF film with a thickness of 30 μm exhibits an EMI SE value of 35 dB in the X-band. The absorption coefficient of CNT@CFO/ANF exceeds 0.9, which effectively reduces secondary reflection pollution compared with CNT/ANF. In photothermal conversion applications, the dual light absorption of conjugated CNTs and semiconductor CFO enables the composite film to exhibit rapid and stable photothermal heating. At AM 1.5G intensity, the stable temperature of CNT@CFO/ANF is 60.1 °C, which is higher than that of CNT/ANF. In addition, the CNT conductive network enables films to achieve rapid response, adjustable, and long-term stable joule heating capabilities. These results indicate that CNT@CFO/ANF aerogel films prepared by a simple and efficient method have great application potential in the field of multifunctional flexible devices. [Display omitted] [ABSTRACT FROM AUTHOR]

Electromagnetic interference (EMI) poses significant challenges to the reliable operation of communication systems, medical devices, and electronic equipment, often resulting in signal degradation, data loss, and equipment failure. To mitigate these issues, this study investigates the development of barium hexaferrite (BHF)/polyvinylidene fluoride (PVDF) composites, synthesized via compression molding, to optimize their electrical and magnetic properties for high-frequency EMI shielding applications. Through comprehensive characterization, including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), vibrating sample magnetometry (VSM), and vector network analysis (VNA), we demonstrate that increasing the BHF content within the composites enhances their complex permittivity, impedance matching, and attenuation coefficients, making them highly effective for EMI shielding. Notably, the composite containing 20 wt% PVDF achieved a reflection loss (RL) of −42 dB at a thickness of 2 mm, indicating superior shielding effectiveness. These results underscore the potential of BHF/PVDF composites as a viable solution for advanced EMI suppression in high-frequency electronic and military applications, combining economic feasibility with robust performance. [ABSTRACT FROM AUTHOR]

Highlights With the wide application of modern electronic devices, the problem of electromagnetic pollution is becoming more and more serious, and the demand for efficient electromagnetic shielding materials is becoming more and more urgent. To address this problem, we homogeneously mixed polyacrylonitrile (PAN), polyvinylpyrrolidone (PVP), and triiron tetraoxide (Fe3O4) nanoparticles by solution blending, and prepared composite precursor membranes by taking advantage of the magnetic properties and good electromagnetic loss characteristics of Fe3O4, as well as the high thermal stability and film‐forming properties of PAN and PVP. Subsequently, carbonized PAN‐PVP/ Fe3O4 composite films with different Fe3O4 contents were successfully prepared by carbonization under high temperature inert atmosphere to convert PAN and PVP into carbon materials. It was found that the PAN‐PVP/ Fe3O4 porous carbon film with 3 wt% Fe3O4 addition had a conductivity of 3.99 S·mm−1 at a thickness of 0.42 mm, and an average EMI SET of 78.9 dB, SEA of 64.8 dB, and SSEt of 1838 dB/(cm2·g−1) in the X‐band, which is a typical wave absorbing material and can meet commercial electromagnetic shielding requirements. This work provides new ideas and methods for the research and development of polymer‐based porous carbonized film as electromagnetic shielding materials. The carbon films with rich porous structure were prepared. Fe3O4 was successfully embedded into the carbon film. Carbon films have an efficient conducting network. Carbon film has excellent electromagnetic shielding performance. The main shielding mode of carbon film is absorption. [ABSTRACT FROM AUTHOR]

Highlights The plain weave fabric made of special fibers was characterized by low density, lightness, ease of co‐planarity, and strong designability, widely used in the production of radar covers, stealth fighter skin, and shielding walls, among other complex electromagnetic shielding components. However, high‐performance fibers, influenced by weaving processes and the interlacing patterns of yarns, possess significant flexibility. Under external loads, fibers are prone to relative slippage, leading to uncertain geometric distortions. Furthermore, changes in their electromagnetic wave transmission properties make it difficult to accurately predict the electromagnetic performance of fiber radar covers. This study primarily focuses on the macro deformation behavior of plain weave fabrics, establishes the geometric mapping relationship for covering curved surface radar covers using plain weave fabrics, and ultimately develops a predictive model for the electromagnetic wave transmittance performance of plain weave fabrics. The research examines the impact of macro and micro geometric structural parameters of plain weave fabrics on electromagnetic wave transmission properties, ultimately enabling quantitative analysis of the electromagnetic wave transmission properties of woven radar covers. The conclusions indicated that changes in the plain weave fabric's pitch directly affect the fiber volume fraction, thereby affecting the transmittance. The greater the shear deformation of plain weave fabric laid on a curved surface, the thicker the fabric and the higher the fiber volume fraction. At the higher curvature ends of curved surfaces, the transmittance was lower than at the lower curvature base. Explained the deformation behavior of plain weave fabric. A wave transmission model for radome made of plain weave fabric was established. The influence mechanism of fabric deformation on wave transmission was revealed. [ABSTRACT FROM AUTHOR]

This study examines the structural, microstructural, magnetic, and dielectric properties of Cr3+-substituted ferrites, specifically Mg0.5Cu0.5Fe1.5Cr0.5O4 and Mg0.5Zn0.5Fe1.5Cr0.5O4, synthesized using the solid-state reaction method. Structural and phase purity assessments were conducted via x-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier Transform Infrared (FTIR) spectroscopy, and Vibrating Sample Magnetometry. XRD patterns confirmed the formation of a single-phase cubic spinel structure in both ferrites, with derived lattice parameters (8.402 and 8.497 Å) and crystallite sizes (44.70 and 30.05 nm) supporting consistent structural integrity. SEM analysis in association with ImageJ software showed grain sizes between 732 and 324 nm, while FTIR spectra revealed characteristic tetrahedral and octahedral vibration bands. Notably, the saturation magnetization increased significantly with Cu2+ concentration, from 38.67 to 60.45 emu/g, indicating an enhancement in magnetic properties. The dielectric behavior, analyzed over a 100–105 Hz range, exhibited Maxwell–Wagner interfacial polarization and electron hopping effects between Fe2+ and Fe3+ ions, contributing to typical dispersion patterns. This improvement in magnetic and dielectric properties, particularly in the Cu-doped samples, underscores the effectiveness of Cr3+ substitution in tuning material characteristics. The findings suggest that these modified ferrites hold promise for high-frequency electronic applications, such as inductors, transformers, and electromagnetic interference shielding materials, where both magnetic stability and efficient dielectric performance are critical. This research contributes valuable insights into the development of advanced ferrites for multifunctional electronic devices. [ABSTRACT FROM AUTHOR]

The ongoing global shift towards sustainability in electrical engineering necessitates novel materials that offer both ecological and technical benefits. Biomass‐derived carbon materials (BCMs) are emerging as cornerstones in this transition due to their sustainability, cost‐effectiveness, and versatile properties. This review explores the expansive role of BCMs across various electrical engineering applications, emphasizing their transformative impact and potential in fostering a sustainable technological ecosystem. The fundamentals of BCMs are investigated, including their unique structures, diverse synthesis procedures, and significant electrical and electrochemical properties. A detailed examination of recent innovations in BCM applications for energy storage, such as batteries and supercapacitors, and their pivotal role in developing advanced electronic components like sensors, detectors, and electromagnetic interference shielding composites has been covered. BCMs offer superior electrical conductivities, tunable surface chemistries, and mechanical properties compared to traditional carbon sources. These can be further enhanced through innovative doping and functionalization techniques. Moreover, this review identifies challenges related to scalability and uniformity in properties and proposes future research directions to overcome these hurdles. By integrating insights from recent studies with a forward‐looking perspective, this paper sets the stage for the next generation of electrical engineering solutions powered by biomass‐derived materials, aligning technological advancement with environmental stewardship. [ABSTRACT FROM AUTHOR]

Electromagnetic waves (EMWs) have become an integral part of our daily lives, but they are causing a new form of environmental pollution, manifesting as electromagnetic interference (EMI) and radio frequency signal leakage. As a result, the demand for innovative, eco-friendly materials capable of blocking EMWs has escalated in the past decade, underscoring the significance of our research. In the realm of modern science, the creation of new materials must consider the starting materials, production costs, energy usage, and the potential for air, water, and soil pollution. Herein, we utilized biowaste materials generated during the distillation of fruit schnapps. The biowaste from apple and quince schnapps distillation was used as starting material, mixed with KOH, and carbonized at 850 °C, in a nitrogen atmosphere. The structure of samples was investigated using various techniques (infrared, Raman, energy-dispersive X-ray, X-ray photoelectron spectroscopies, thermogravimetric analysis, BET surface area analyzer). Encouragingly, these materials demonstrated the ability to block EMWs within a frequency range of 8 to 12 GHz. Shielding efficiency was measured using waveguide adapters connected to ports (1 and 2) of the vector network analyzer using radio-frequency coaxial cables. At a frequency of 10 GHz, carbonized biowaste blocks 78.5% of the incident electromagnetic wave. [ABSTRACT FROM AUTHOR]

The present paper proposes a dual-band frequency selective surface for 5G and 6G shielding applications. The design evolves from a fractal circular patch etched from the metallic square patch to achieve wideband, angular stability, and polarisation insensitivity up to incident angles of 45°. The proposed FSS unit cell has a dimension of 0.2λ0 ×0.2λ0, where λ0 is the free space wavelength corresponding to the resonant frequency. The FSS shield provides dual stopbands centred at 3.5 GHz and 5.9 GHz with fractional bandwidths of 13.4% and 5.08%, respectively. A prototype was fabricated on an FR4 substrate to validate the design, which includes 6 × 6 elements with dimensions of 108.8 mm × 108.8 mm × 1.6 mm. Measurements have shown a consistent shielding effectiveness of 35 dB at the lower band and more than 27 dB at the upper band, which are in good agreement with simulation results. The compact size, simple geometry, and descent shielding effectiveness are the unique features of the proposed design which may be a good choice for 5G and 6G communications. [ABSTRACT FROM AUTHOR]

Porous biodegradable polybutylene adipate terephthalate (PBAT)‐based material, used in wearable electronics for sensing human motion, is beneficial for environmental protection. Although PBAT demonstrates good elongation at break and impact performance, specific studies on its processing, modification, and porous structure are needed. Therefore, PBAT/single‐walled carbon nanotube (SWCNT) porous material was prepared via a salt‐templating method. It was found that part of the SWCNT was embedded in the walls of the pores in the PBAT substrate, while another part was exposed on the pore surface. PBAT served as the structural framework, and SWCNT functioned mainly as the active component, especially the SWCNT exposed on the surface. This unique microstructure imparted the porous material with desirable piezoresistive properties and effective electromagnetic interference (EMI) shielding capabilities. When the material was compressed, the exposed SWCNT was forced into closer contact, increasing the number of electrical transport pathways and further enhancing conductivity. The resulting porous sensor exhibited a notable response to strain up to 100% and demonstrated high sensitivity (1.25) while maintaining robust cyclic stability after 1000 cycles. Human pulse and finger flexion were successfully recorded using the fabricated porous sensor. Moreover, the porous material displayed EMI shielding capabilities, primarily through the absorption of electromagnetic (EM) waves, a phenomenon associated with the rough surface of the pores created by the exposed SWCNT. The overall electromagnetic shielding effectiveness was around 60 dB. Given these advantages, the green biodegradable material PBAT shows significant potential for application in piezoresistive sensors and electromagnetic interference shielding with appropriate modification and preparation. [ABSTRACT FROM AUTHOR]

With the growing penetration of microwave applications in modern society, exposure to electromagnetic waves (EMWs) may become an important public health problem. In addition, the coexistence of radio-frequency (RF) devices and systems induces Electromagnetic Interference (EMI) leading to electromagnetic perturbations and lifetime reduction. Consequently, shielding materials capable of blocking EMWs are highly required. In this paper, composite materials using graphene oxide (GO) and silver nanowires (AgNWs) were studied as potential EMW shielding materials. Both GO and AgNWs were synthesized and used to obtain GO-AgNWs composites with different mass ratios of GO and AgNWs (from 1:9 to 3:1, respectively). The sheet size of GO was between 150 and 2000 nm and the thicknesses of flakes in the range of 2–5 nm. UV–Vis spectroscopy proved the successful production of AgNWs and the establishing interaction of NWs with GO sheets in the produced composites. The changes in the surface hydrophilicity/hydrophobicity showed that the selected eco-friendly reduction with ascorbic acid as a reducing agent was efficient in inducing the lowering in the hydrophilicity of the GO surface, while in the case of reduced GO (rGO) functionalized with AgNWs, the contact angle was 73.6° which between rGO and GO due to AgNWs hydrophilic character. The average thickness of free-standing films was around 14.8 μm. We studied the ratio between these nanomaterials to modulate shielding efficiency in a broad microwave frequency of up to 18 GHz. The shielding efficiency of around 6.5 dB was measured for the rGO free-standing film. [ABSTRACT FROM AUTHOR]

There has been a recent transition from conventional textiles to smart and electronic textiles, mostly due to the rise of wearable technology. Functional yarns have been created to fulfil the varied application needs in various environments. Conductive yarns have attracted considerable interest because of their exceptional softness, comfort, and diverse capabilities, such as electromagnetic shielding and soft sensors. This paper presents a comprehensive examination of spinning techniques utilized for the production of conductive yarns, incorporating a range of conductive additives, conductive fabrics, and conventional electrical elements. The text emphasizes that the performance of conductive yarns is significantly affected by their structure, which is dictated by the geometrical configurations of their elements, and the spinning geometry, commonly known as the twisted triangle. The performance of conductive yarns is primarily determined by the concentration of conductive components in their structure. Moreover, this paper examines the possible uses of conductive fabrics in several technical domains. The mentioned applications encompass antistatic packaging, heating elements, wearable electronics, smart membrane technology, data storage and transmission, sensors, actuators, and protection against electromagnetic interference and electrostatic discharge. Conductive textiles possess a versatile character that presents a wide range of opportunities for progress in multiple industries. To summarize, this review thoroughly examines the spinning methods used to create conductive yarns, with a particular focus on the significance of yarn structure in influencing their performance. Furthermore, it emphasizes the wide range of technological applications in which conductive textiles can be utilized. [ABSTRACT FROM AUTHOR]

Objective: To propose a deep learning-based low-field mobile MRI strategy for fast, high-quality, unshielded imaging using minimal hardware resources. Methods: Firstly, we analyze the correlation of EMI signals between the sensing coil and the MRI coil to preliminarily verify the feasibility of active EMI shielding using a single sensing coil. Then, a powerful deep learning EMI elimination model is proposed, which can accurately predict the EMI components in the MRI coil signals using EMI signals from at least one sensing coil. Further, deep learning models with different task objectives (super-resolution and denoising) are strategically stacked for multi-level post-processing to enable fast and high-quality low-field MRI. Finally, extensive phantom and brain experiments were conducted on a home-built 0.2 T mobile brain scanner for the evaluation of the proposed strategy. Results: 20 healthy volunteers were recruited to participate in the experiment. The results show that the proposed strategy enables the 0.2 T scanner to generate images with sufficient anatomical information and diagnostic value under unshielded conditions using a single sensing coil. In particular, the EMI elimination outperforms the state-of-the-art deep learning methods and numerical computation methods. In addition, 2 × super-resolution (DDSRNet) and denoising (SwinIR) techniques enable further improvements in imaging speed and quality. Discussion: The proposed strategy enables low-field mobile MRI scanners to achieve fast, high-quality imaging under unshielded conditions using minimal hardware resources, which has great significance for the widespread deployment of low-field mobile MRI scanners. [ABSTRACT FROM AUTHOR]