Electromagnetic Interference Research Articles

Multifunctional Nacre-Like Nanocomposite Papers for Electromagnetic Interference Shielding via Heterocyclic Aramid/MXene Template-Assisted In-Situ Polypyrrole Assembly

HighlightsThe large-scale, high-strength, super-tough, and multifunctional nacre-like heterocyclic aramid (HA)/MXene@polypyrrole (PPy) (HMP) nanocomposite papers were fabricated using the in-situ assembly of PPy onto the HA/MXene hydrogel template.The "brick-and-mortar" layered structure and abundant hydrogen-bonding interactions among MXene, PPy, and HA respond cooperatively to external stress and effectively increase the mechanical properties of HMP nanocomposite papers.The templating effect from HA/MXene was utilized to guide the assembly of conducting polymers, leading to high electrical conductivity and outstanding electromagnetic interference shielding performance.

Controlled Distribution of MXene on the Pore Walls of Polyarylene Ether Nitrile Porous Films for Absorption-Dominated Electromagnetic Interference Shielding Materials.

With the increasing application of electronic devices, absorption-dominated electromagnetic interference shielding materials (EMISM) have garnered significant attention for preventing secondary electromagnetic pollution. In this study, polyethyleneimine (PEI)-modified MXene (PEI@MXene) is fabricated and achieved its controlled distribution on the pore walls of polyarylene ether nitrile (PEN) porous films via the phase inversion method (PIM) to obtain a closed porous skeleton of MXene on the pore walls (CPS-MPW). The resulting PEI@MXene/PEN composite film (CFx) exhibited absorption-dominated EMIS efficiency (EMISE). Attributing to the strong interaction between PEI and the hydrophilic segment of amphiphilic Pluronic F127, with its hydrophobic segment anchored by the PEN matrix, PEI@MXene is directionally distributed on the pore walls of CFx. In addition, resulting from the cladding of MXene with PEI and isolating it with closed honeycomb pores, the obtained CFx are insulators without forming aconductive network. As a result, these CFx demonstrate absorption-dominated EMISE with the highest SET of 41.2 dB and coefficient A higher than 0.51. Further continuous hot pressing of CFx results in thinner and denser films with an impressive specific EMISE up to 750 dBcm-1. The successful fabrication of these CPS-MPW-type CFx with absorption-dominated EMISE provides a reference for developing and preparing novel EMISM.

Holographic multiplexing metasurface with twisted diffractive neural network

As the cornerstone of AI generated content, data drives human-machine interaction and is essential for developing sophisticated deep learning agents. Nevertheless, the associated data storage poses a formidable challenge from conventional energy-intensive planar storage, high maintenance cost, and the susceptibility to electromagnetic interference. In this work, we introduce the concept of metasurface disk, meta-disk, to expand the capacity limits of optical holographic storage by leveraging uncorrelated structural twist. We develop a physical twisted neural network to describe the optical behavior of the meta-disk and conduct a comprehensive lateral error analysis, where the meta-disk stores large volumes of information through internal structural multiplexing. Two-layer 640 µm x 640 µm meta-disk is sufficient to store over hundreds of high-fidelity images with SSIM of 0.8. By harnessing advanced three-dimensional (3D) printing technology, optical holographic storage is experimentally demonstrated with Pancharatnam-Berry metasurfaces. Our technology provides essential backing for the next generation of optical storage, display, encryption, and multifunctional optical analog computing.

Scalable ultrastrong MXene films with superior osteogenesis.

Titanium carbide MXene flakes have promising applications in aerospace, flexible electronic devices and biomedicine owing to their superior mechanical properties1 and electrical conductivity2 and good photothermal conversion3, biocompatibility4 and osteoinductivity5. It is highly desired yet very challenging to assemble MXene flakes into macroscopic high-performance materials in a scalable manner. Here we demonstrate a scalable strategy to fabricate high-performance MXene films by roll-to-roll-assisted blade coating (RBC) integrated with sequential bridging, providing good photothermal conversion and osteogenesis efficiency under near-infrared irradiation. MXene flakes were first bridged with silk sericin by hydrogen bonding and then assembled into macroscopic films using a continuous RBC process, followed by ionic bridging to freeze their aligned structure. The resultant large-scale MXene films with strong interlayer interactions are highly aligned and densified, exhibiting high tensile strength (755 MPa), toughness (17.4 MJ m-3) and electromagnetic interference (EMI) shielding capacity (78,000 dB cm2 g-1), as well as good ambient stability, photothermal conversion and bone regeneration performance. The proposed strategy not only paves a feasible way for realizing the practical applications of MXene in the fields of flexible EMI shielding materials and bone tissue engineering but also provides an avenue for the high-performance and scalable assembly of other two-dimensional flakes.

Electrical and EMI shielding studies of ferrite/MWCNTs/PVDF composites

AbstractIn this work, CFO/MWCNTs/PVDF and BFO/MWCNTs/PVDF composites are prepared and the comparative analysis of electrical properties and electromagnetic interference (EMI) shielding performance of both type of composites are investigated. The dielectric and conductivity characteristics are observed with varying ferrite concentration, frequency, and temperature. Ferroelectric properties are also obtained at 6 kV/cm field and EMI shielding behavior is observed in 8–12 GHz frequency range. Results exhibited that the studied properties of the composite enhances with increasing ferrite concentration that attributed to increased amount of magnetic nanoparticles. Cobalt ferrite (CFO) filled polyvinylidene fluoride (PVDF) composite is showing better properties as compared to barium ferrite (BFO) filled PVDF composites. The mechanism involve for this behavior is discussed herein.

Development of Flexible Hydrophobic Polypropylene/SPCB/GNP Hybrid Nanocomposite Films With Excellent EMI Shielding and Mechanical Properties

ABSTRACTThe demand for effective electromagnetic interference (EMI) shielding materials has driven the development of novel and facile approach for fabrication of conductive polymer nanocomposites. In this study, a polypropylene (PP)‐based hybrid nanocomposite was prepared by incorporating Super P conductive carbon black (SPCB) and graphene nanoplatelets (GNP) via latex technology. A simplistic method of fabrication was adopted where the nanofillers were stirred into the PP latex at room temperature, ensuring the proper dispersion of fillers within the matrix. Hybridizing the nanocomposite by the usage of two different fillers has resulted in a substantial improvement in EMI shielding performance of the material along with its mechanical and thermal properties. The samples were fabricated and tested in three different thicknesses to ensure that EMI shielding effectiveness (EMI SE) is a thickness dependent property and also the studies were carried out over a broad range of microwave frequency. A high electrical conductivity of 7.6 S m−1 was obtained and exceptional EMI SE of 65 dB (X band), 69.76 dB (Ku band), and 72.38 dB (K band) was showcased by 2 mm thickness composites. The optical images of PP latex incorporated with the fillers gave a clear understanding about the formation of conducting networks within the polymer matrix at percolation threshold. The addition of SPCB and GNP also showed a significant increase in hardness and tensile strength of the composite and helped in protecting the polymer matrix against photo radiation. The fillers also aided in the enhancement of the hydrophobicity of the films. The thermal stability, crystallization temperature (TC) and melting temperature (TM) of the composites were also improved when compared to that of neat The works aims at fabricating a hydrophobic and low‐density polymer nanocomposite showing excellent absorption dominant EMI SE.

Investigating Electromagnetic Interference Induced Risks for Autonomous Driving

Abstract. The results of immunity tests on components of self-driving automobiles to radiated high power electromagnetic (HPEM) pulses are presented in this work. It is of particular interest to investigate such automobiles' resilience towards deliberate attacks with electromagnetic interference (EMI). Different types of HPEM capabilities at the Bundeswehr Research Institute for Protective Technologies and CBRN Protection (WIS) in Munster are applied for this investigation. Two types of automotive components have been tested, a two-axis acceleration sensor and an electronic power steering unit. Statistics of errors from the devices under test (DUTs), as well as a characterization of the applied pulses are presented. A correlation can be drawn between the pulse repetition rate or the amplitude of the applied pulses and the severity of the effect on the DUTs.

Development and Evaluation of a Robust UART Communication System with Enhanced Interference Resistance

Interference is a significant issue in UART communication, often causing data jitter and distortion, particularly in industrial environments. This study addresses these challenges by developing an anti-interference UART system that includes the design and implementation of receiving, processing, and sending modules. The system utilizes techniques such as multi-level sampling, synchronization, and cumulative decision-making to enhance data transmission accuracy and reliability. In embedded systems, electromagnetic interference (EMI) poses a major problem, leading to potential data loss and communication failures. Reliable communication is crucial for maintaining the performance and safety of industrial operations. The anti-interference UART system developed in this study aims to improve operational stability by mitigating the effects of EMI. The system’s performance was validated through extensive simulations, demonstrating its ability to maintain stable and accurate data transmission even under various interference conditions. The results show significant improvements in data integrity and communication reliability. This paper presents a comprehensive approach to designing, implementing, and validating a robust UART system that can effectively operate in challenging environments, ensuring reliable data communication and enhancing overall system performance.

Alginate-based functionalized, remote, light-responsive hydrogel transducer for synergistic mild photo thermoelectric stimulation for tumor therapy

Photothermal therapy (PTT) is an effective cancer treatment that circumvents the resistance caused by chemotherapy drugs. Conventional PTT has a relatively high temperature, which is better able to kill tumor tissues, but it is also more damaging to normal tissues. Mild PTT avoids these high temperatures, but its corresponding killing ability becomes lower and enhances the heat resistance of cancer cells, causing tumor self-protection and reducing the therapeutic effect of PTT. Here, we reported a new, remotely stimulable, mild-temperature PTT combined with electrical stimulation-induced ionic interference therapy. We introduced MXenes into alginate based thermoresponsive PVA/P(NIPAm-co-SA) hydrogel (PPS) to formulate mechanically reliable hydrogel electrolyte-based supercapacitors as an ion homeostasis perturbator. The artificially controlled duration of near-infrared radiation modulates the PTT cycle temperature, which is controllably maintained at a little under 45 °C to reduce Hsp90 overexpression. Light-induced phase transitions in the hydrogel produce voltages that resemble low-intensity, alternating electric fields. Moreover, chronic piezoelectric stimulation can inhibit cancer cell proliferation by upregulating the expression of genes encoding Kir3.2 inwardly rectifying potassium channels, by interfering with Ca2+ homeostasis, and by affecting mitotic spindle organization during mitosis. In vivo and in vitro antitumor studies on the 4T1 model suggest that this functionalized, remote, light-responsive transducer is an effective and promising tool for the treatment of tumors.

Three-Dimensional Reconstruction of Retaining Structure Defects from Crosshole Ground Penetrating Radar Data Using a Generative Adversarial Network

Crosshole ground penetrating radar (GPR) is an efficient method for ensuring the quality of retaining structures without the need for excavation. However, interpreting crosshole GPR data is time-consuming and prone to inaccuracies. To address this challenge, we proposed a novel three-dimensional (3D) reconstruction method based on a generative adversarial network (GAN) to recover 3D permittivity distributions from crosshole GPR images. The established framework, named CGPR2VOX, integrates a fully connected layer, a residual network, and a specialized 3D decoder in the generator to effectively translate crosshole GPR data into 3D permittivity voxels. The discriminator was designed to enhance the generator’s performance by ensuring the physical plausibility and accuracy of the reconstructed models. This adversarial training mechanism enables the network to learn non-linear relationships between crosshole GPR data and subsurface permittivity distributions. CGPR2VOX was trained using a dataset generated through finite-difference time-domain (FDTD) simulations, achieving precision, recall and F1-score of 91.43%, 96.97% and 94.12%, respectively. Model experiments validate that the relative errors of the estimated positions of the defects were 1.67%, 1.65%, and 1.30% in the X-, Y-, and Z-direction, respectively. Meanwhile, the method exhibits noteworthy generalization capabilities under complex conditions, including condition variations, heterogeneous materials and electromagnetic noise, highlighting its reliability and effectiveness for practical quality assurance of retaining structures.

A Facile Method in Fabricating Flexible Conductive Composites with Large-Size Segregated Structures for Electromagnetic Interference Shielding.

To resist the plastic deformation of polymer particles during hot press molding, high molecular weights, and moduli are required for composites with segregated structures, thus the prepared composites exhibit poor flexibility. Also, larger particle sizes can bring lower percolation thresholds while the ensuing greater deformation destroys the conductive network. Moreover, segregated composites still face preparation complexities. Herein, a facile method for developing flexible composites with large-size segregated structures is proposed. First, silver-coated polydopamine-modified reduced graphene oxide (Ag@PrGO), as conductive fillers, is prepared by electroless plating. Next, polydimethylsiloxane (PDMS)-coated polyolefin elastomer (POE) beads are put into a bag containing the fillers. After a simple shaking, the fillers are adhered to the POE surface as the cohesive property of cured PDMS. Finally, flexible composites with large-size segregated structures are obtained via hot pressing. Benefiting from the 2D structure of the Ag@PrGO and the ability to slip, the conductive networks possess adaptable deformability. The prepared composites exhibit excellent electrical conductivity (203.55 Scm-1) at filler volume fractions of 3.4 vol%. The EMI shielding effectiveness can reach 70dB in the X-band at a thickness of 1.9mm and remains stable after bending and rubbing damage. This work paves the way for constructing large-size segregated structures.

Enhancing metacomposite properties and electromagnetic interference shielding: exploring the interplay between manufacturing processability of carbon fiber elastomeric composite and permittivity/permeability effects

Enhancing metacomposite properties and electromagnetic interference shielding: exploring the interplay between manufacturing processability of carbon fiber elastomeric composite and permittivity/permeability effects

A Durable Textile With Advanced Thermal Functions and Electromagnetic Shielding.

In the face of increasingly variable cold climates and diverse individual temperature regulation demands, personal thermal management (PTM) textiles with electromagnetic shielding have obtained significant attention. However, the PTM textiles face several challenges, including single heating mode, insufficient durability, and complex preparation processes. Herein, an all-day PTM textile Cotton@PDA/AgNPs (CPANS) with energy-free PRH, energy-saving solar heating, compensatory electricalheating, electromagnetic interference (EMI) shielding, and outstanding durability is fabricated by sequentially growing polydopamine (PDA) and silver nanoparticles (AgNPs) on the cotton fabric (CF). The CPANS exhibits low mid-infrared emissivity (36.6%) and high absorptivity (70.8%), which guarantees the energy-saving heating capability. Moreover, the conductivity of the CPANS is ≈11109Sm-1, enabling an electrical heating temperature of ≈177°C under a low voltage of 1.1V and superb EMI shielding effectiveness (≈60dB). The remarkable adhesive properties of the PDA ensure that the desired durability of the CPANS remains high even after rigorous physical treatments. This innovation shows enormous potential for wearable integrated garments in the future and offers a new ideal for PTM fabrics in the cold.

Hybrid control for capacitor-assisted Z-source inverter in grid-connected photovoltaic system

Renewable energy integration into the power grid is essential for sustainable energy systems, but maintaining efficiency and reliability in such systems remains a key challenge. This study introduces a novel hybrid control topology for a Capacitor-Assisted Extended Boost Z-Source Multilevel Inverter in a grid associated solar photovoltaic (PV) structure. The suggested hybrid technique implies a united implementation of a Gannet Optimization Algorithm and Spiking Deep Residual Network and usually referred as GOA-SDRN technique. Initially, the modelling of the inverter is collected to get the best signal by the proposed controller. The proposed inverter configuration consists of a minimal quantity of diodes, switches, and sources. This configuration also offers advantages like less total harmonic distortion (THD) and reduced electromagnetic interference, making it a favourable choice for PV integration. The GOA is employed to determine the most favourable gain limiting factor based on a variation of power from their regular values. This control method ideally satisfies the load demand while reducing changes in the system limiting factor and external disturbances. The proposed control topology is executed in MATLAB and the concept is contrasted to different techniques. The THD values of existing methods such as Particle Swarm Optimization, Genetic Algorithm, and Grasshopper Optimization Algorithm are 1.36 %,0.89 %, and 1.99 % respectively, while the THD value of the proposedmethod is 0.63 %, demonstrating its optimal performance over existing methods. The proposed GOA-SDRN technique provides an effective solution for enhancing inverter efficiency and reducing distortion in grid-associated PV systems.

Structure‐function integrated design of electromagnetic interference shielding and mechanical properties of 2D carbon fiber reinforced polymer composites based on absorption loss regulation

Structure‐function integrated design of electromagnetic interference shielding and mechanical properties of <scp>2D</scp> carbon fiber reinforced polymer composites based on absorption loss regulation

Gap Analysis of Ambient Electromagnetic Noise Measurements Stored in the ITU Data Banks.

For any radio frequency (RF) sensor (receiver) to function optimally, the ambient noise field strength, converted to electrical power by the transducer (antenna), must be lower than the in-ternal noise of that sensor. Therefore, knowledge of the expected ambient noise level is essential for the design of sensors for earth observation, atmospheric research, radio astronomy or navigation. The International Telecommunication Union (ITU) provides a model that predicts ambient man-made noise levels, differentiated by frequency, origin and environment. This is entirely empirical model is based on data from the 1960's and 1970's. In recent years, 90,205 noise measurements have been collected to update the model. The analysis of that data set presented here is essential as it shows a pitfall to avoid: despite to size of the data set it is sparce over the parameter space, and unacceptable biases occur when a purely empirical model is based on them. The paper proposes another approach: to create a mathematical model based on physics that can be fine-tuned and validated using these collected measurements, without producing the biases. A revolutionary side effect of such a model would be the linking of two currently isolated domains, that of spectrum management and electromagnetic compatibility.

Biomimetic Ambient‐Pressure‐Dried Aerogels with Oriented Microstructures for Enhanced Electromagnetic Shielding

AbstractOriented aerogels, emerging as a new generation of lightweight electromagnetic interference (EMI) materials, often face complex synthesis processes. While creating an orderly oriented microstructure for EMI aerogels through ambient pressure drying (APD) shows promise, it remains a significant challenge. Here, inspired by the directional grown structure of the plant, a new strategy that employs rapid precursor orientation followed by slow cross‐linking to achieve the APD of directional EMI aerogels is proposed. This approach demonstrates that low‐temperature oriented polymerization of polyaniline enables strong cross‐linking with poly(3,4‐ethylenedioxythiophene) and alginate, forming a robust conductive directional skeleton and mitigating surface tension issues during mild drying. The resulting aerogel features high conductivity (48.84 S m−1), excellent flame retardancy, and impressive compressive strength. Notably, its sturdy frame allows for further enhancement with other functional materials, such as Mxene, through re‐processing and re‐drying. The tree‐branch‐like aerogel achieves a significantly improved EMI shielding effectiveness of 50.3 dB across an ultrawideband range of 8.2–40 GHz. This strategy offers a new idea for the straightforward preparation of functional aerogels with programmability and oriented microstructures using ambient drying.

Pearl‐Inspired Colored Carbon Fibers with Electromagnetic Interference and Optical Camouflage Properties

Carbon fibers (CFs) are widely used in cutting‐edge and civilian fields due to their excellent comprehensive properties such as high strength and high modulus, superior corrosion and friction resistances, excellent thermal stability, light weight, and high electrical conductivity. However, their natural ultra‐black appearance is difficult to meet the aesthetic needs of today's civilian sector and the need for optical stealth in the military field. In addition, conventional coloring methods are difficult to effectively adhere to CF surfaces due to high crystallinity and highly inert surface caused by their graphite‐like structure. In this work, inspired by the nacre structural color of pearls, colored CFs with 1D photonic crystal structure are prepared by cyclically depositing amorphous (Al2O3 + TiO2) layers on the surface of carbon CFs through atomic layer deposition (ALD). The obtained CFs exhibit brilliant colors and excellent environmental durability in extreme environments. Moreover, the colored CFs also exhibit high EMI shielding effectiveness (45 dB) and optical stealth properties, which can be used in emerging optical devices and electromagnetic and optical stealth equipment.

Degradation of crystalline silicon solar cells caused by lightning induced impulse surge

Abstract Crystalline silicon (c-Si) solar cells are connected in series to form photovoltaic modules, which are installed in wide-open areas. They are exposed to lightning electromagnetic (EM) interference at high risk. The lightning EM field can induce an impulse surge in the loop of the solar-cell string, and c-Si solar cells are prone to damage. To study the effect of lightning surge on monocrystalline silicon cells and polycrystalline silicon cells, impulse voltage tests are conducted. Semiconductor structures of c-Si solar cells after testing are observed using scanning electron microscopy. The results indicate that the lightning surge will generate some cracks and defects in the P–N junction. Under a strong electric field, the N-type emitter layer and the grain boundary can be destroyed, which contributes to the degradation of the c-Si solar cell. Compared to monocrystalline silicon cells, polycrystalline silicon cells can withstand greater forward lightning surge; however, their maximum reverse lightning surge is relatively low.

Measurements of Stray Radiation from Medical Devices in Hospitals

The main objective of this study was to look for the electromagnetic interference produced by medical devices in hospitals and to evaluate its impacts on the proper functions of such devices. However, the present study encountered other important problems with regard to CT scanner and X-ray Imaging systems. Such problems demand fast responses in order to secure health safety for the patients and the operators of such systems. ORIGINAL RESEARCH ARTICLE | Oct. 23, 2024