Effects Of Electromagnetic Interference Research Articles

Synergistic magnetic/dielectric loss and layered structural design of Ni@carbon fiber/Ag@graphene fiber/polydimethylsiloxane composite for high-absorption EMI shielding

Simultaneously achieving excellent shielding effectiveness (SE) and high absorption rate of flexible electromagnetic interference (EMI) shielding materials has become a growing demand for the new generation of highly integrated electronic devices. This study constructed a double-layer polydimethylsiloxane (PDMS) EMI shielding composite film, with the upper layer using Ni-plated carbon fiber (Ni@CF) as the high absorption loss part and the lower layer using Ag-plated graphene fiber (Ag@GF) as the reflection attenuation part. Due to the synergistic magnetic/dielectric loss effect in the upper layer, high electrical conductivity in the lower layer, and the shielding mechanism of “absorption-reflection-reabsorption” induced by the double-layer structure, this composite film achieves efficient EMI shielding performance and high absorption characteristics in the X-band. The EMI SE values of the 2 mm thick film containing 0.03 wt% Ni@CF and 1.2 wt% Ag@GF reach 33.7 dB, while shielding effectiveness of reflection (SER) and absorption (SEA) is 0.8 dB and 32.9 dB, respectively. This result means that the composite film only reflects 17.2 % of the microwaves while shielding 99.9 % and absorbs nearly 82.7 %, exhibiting a significant absorption-dominated shielding mechanism. This flexible and efficient shielding film with a high absorption rate suits portable and wearable intelligent electronic products to reduce secondary electromagnetic pollution.

Structural Design for EMI Shielding: From Underlying Mechanisms to Common Pitfalls.

Modern human civilization deeply relies on the rapid advancement of cutting-edge electronic systems that have revolutionized communication, education, aviation, and entertainment. However, the electromagnetic interference (EMI) generated by digital systems poses a significant threat to the society, potentially leading to a future crisis. While numerous efforts are made to develop nanotechnological shielding systems to mitigate the detrimental effects of EMI, there is limited focus on creating absorption-dominant shielding solutions. Achieving absorption-dominant EMI shields requires careful structural design engineering, starting from the smallest components and considering the most effective electromagnetic wave attenuating factors. This review offers a comprehensive overview of shielding structures, emphasizing the critical elements of absorption-dominant shielding design, shielding mechanisms, limitations of both traditional and nanotechnological EMI shields, and common misconceptions about the foundational principles of EMI shielding science. This systematic review serves as a scientific guide for designing shielding structures that prioritize absorption, highlighting an often-overlooked aspect of shielding science.

3D interconnected graphene nanoplatelets and nickel ferrite based silicone rubber foams for effective electromagnetic interference shielding and thermal insulation performance

In the present study, porous composite foams made of silicon rubber (SR), graphene nanoplatelets (GnP), and nickel ferrite (NiFe2O4) nanoparticles were developed using the salt template approach. SR act as a 3D porous network, the conductive channel provided by graphene nanoplatelets and the magnetic and dielectric loss provided by the NiFe2O4 and the composite foam as a whole showed absorption-dominated EMI shielding due to synergism between GnP and NiFe2O4. Without NiFe2O4, the total EMI SE is 23 dB, while different NiFe2O4 weight percentages (0%, 3%, 6%, & 9%) increase the SET up to 36.7 dB. The thermal conductivity of this prepared sample is found to be 0.0313 Wm−1K−1 for 9 wt% filler content of NiFe2O4. It shows a moderately low value as compared to existing polymer composites. The resulting SR/GnP@NiFe2O4 composite foams, which are lightweight, strong, and multifunctional, have straightforward synthesis procedures and have a myriad of possible uses for EMI shielding systems and thermal insulations in the disciplines of aerospace, military engineering, electrical engineering and electronics.

Microwave absorption performance for Cu, Co, and Ti co-doped SrFe12O19 as a function of incident angle

Microwave-absorbing materials (MAMs) are essential for mitigating the unwanted effects of electromagnetic interference and microwave pollution. MAMs are also used in 5G technology, energy harvesting, information security, and military technology (such as reduced radar cross-section). In this work, SrFe12–2xCux/2Cox/2TixO19 samples, prepared by using a ball mill and heat treatment method, showed their superior microwave dissipation features in both effective absorption bandwidth (EAB) and reflection loss (RL) values for the microwave incident angle of 0°, where EAB and RL values reached 15.90 GHz and −42.86 dB, respectively. The optimum RL values would change with the variation of the incident microwave angle. RL values at a specific oblique angle could exhibit better RL values for both transverse electric (TE) and transverse magnetic (TM) polarization modes, except for the x = 0.15 (SrM15) sample for TE mode. In detail, the x = 0 (SrM0) sample achieved the lowest RL value of −71.28 dB for the incident angle of 20° in the TE polarization mode, which was much better than that of the normal incident. The RL of the SrM15 sample in TM mode was significantly enhanced and reached a value of −66.48 dB for an incident angle of 10°. The increase in the RL values resulted from the superior values of complex permittivity and permeability and their matching. In addition, the improvement in RL values could be attributed to the increase in incident and refraction angles as well as the longer pathway of the microwave inside the samples. These discoveries also illustrate that SrFe12–2xCux/2Cox/2TixO19 samples hold promise for various everyday applications, even when exposed to oblique angle variation.

Heart Rhythm New Zealand consensus statement on the practical management of cardiac implanted electronic devices in the peri-operative environment.

Electrosurgery is commonly used during a range of operations in order to maintain effective haemostasis. This can cause electromagnetic interference (EMI) with cardiac implanted electronic devices (CIEDs), which prevents normal device function. CIEDs include pacemakers (PPM), implantable cardiac defibrillators (ICD), cardiac resynchronisation therapy devices-both pacemakers and defibrillators (CRT-P/CRT-D)-and implantable loop recorders (ILRs). Damage to the generator, inhibition of pacing, activation of asynchronous pacing and ventricular fibrillation can all be induced by electrocautery. An active management plan for CIEDs during electrosurgery is critical to minimise these adverse effects of EMI. Purpose: To facilitate the safe and effective peri-operative management of CIED patients during electrosurgery.

Robust EMI elimination for RF shielding-free MRI through deep learning direct MR signal prediction.

To develop a new electromagnetic interference (EMI) elimination strategy for RF shielding-free MRI via active EMI sensing and deep learning direct MR signal prediction (Deep-DSP). Deep-DSP is proposed to directly predict EMI-free MR signals. During scanning, MRI receive coil and EMI sensing coils simultaneously sample data within two windows (i.e., for MR data and EMI characterization data acquisition, respectively). Afterward, a residual U-Net model is trained using synthetic MRI receive coil data and EMI sensing coil data acquired during EMI signal characterization window, to predict EMI-free MR signals from signals acquired by MRI receive and EMI sensing coils. The trained model is then used to directly predict EMI-free MR signals from data acquired by MRI receive and sensing coils during the MR signal-acquisition window. This strategy was evaluated on an ultralow-field 0.055T brain MRI scanner without any RF shielding and a 1.5T whole-body scanner with incomplete RF shielding. Deep-DSP accurately predicted EMI-free MR signals in presence of strong EMI. It outperformed recently developed EDITER and convolutional neural network methods, yielding better EMI elimination and enabling use of few EMI sensing coils. Furthermore, it could work well without dedicated EMI characterization data. Deep-DSP presents an effective EMI elimination strategy that outperforms existing methods, advancing toward truly portable and patient-friendly MRI. It exploits electromagnetic coupling between MRI receive and EMI sensing coils as well as typical MR signal characteristics. Despite its deep learning nature, Deep-DSP framework is computationally simple and efficient.

Investigation on surface metallization of epoxy resin and its electromagnetic interference shielding performance

In this study, aluminum and aluminum/nickel metal layers with varying thicknesses were deposited on the surface of epoxy resin using electron beam evaporation technology. The research aimed to explore and compare the impact of the thickness and material of the metal layer on electromagnetic interference shielding efficiency. The study revealed that the metal layer on the pre-treated surface of the epoxy resin displays a more complete morphology with uniform coverage and a distinctive stratification in the aluminum/nickel (Al/Ni) metal layer. The application of aluminum and aluminum/nickel metal layers onto the surface of epoxy resin demonstrates effective electromagnetic interference shielding. The investigation reveals that electromagnetic interference shielding efficiency escalates with the thickness of the metal layer within the test frequency range of 4 GHz to 15 GHz. Notably, it attains 70 dB when the aluminum/nickel metal layer achieves a thickness of 1 μm. These findings signify that the aluminum/nickel metal layer displays outstanding electromagnetic interference shielding performance, making it suitable for widespread application in the domain of electromagnetic interference shielding for polymer composites.

Metaheuristic aided structural topology optimization method for heat sink design with low electromagnetic interference

This study investigates the application of the Metaheuristic Aided Structural Topology Optimization (MASTO) method as a novel approach to address the multiphysics design challenge of creating a heat sink with both high heat conductivity and minimal Electromagnetic Interference (EMI). A distinctive 2D layout with elongated fins is examined for electromagnetic traits, highlighting resonance-related EMI concerns. MASTO proves to be a valuable tool for navigating the complex design space, yielding thoughtfully optimized solutions that harmonize efficient heat dissipation with effective EMI control. By merging simulation findings with practical observations, this study underscores the potential of the MASTO method in achieving effective designs for intricate multiphysics optimization problems. Specifically, the method's capacity to address the complex interplay of heat transfer with convection and the suppression of electromagnetic emissions is showcased. Moreover, the study demonstrates the feasibility of translating these solutions into tangible outcomes through manufacturing processes.

Multifunctional syndiotacticity-rich poly (vinyl alcohol)/MXene sediment for multilayered composite films with effective electromagnetic interference shielding and thermal conductivity

Utilizing remarkable polymer matrix and efficient filler to propose an ingenious strategy for designing composite films synergistically with high electromagnetic interference shielding effectiveness (EMI SE) and thermal conductivity. Herein, a novel type of flexible composite film based on syndiotacticity-rich poly (vinyl alcohol) (sPVA)/modified MXene sediment (mMS) is fabricated through an alternating casting approach. The sPVA/mMS multilayered film containing effective noncovalent combining between sPVA layer and mMS layer not only presents a high strength of ∼66.3 MPa but also possesses a superior electrical conductivity of 683 S/m. Notably, the mMS layer with dense conductive and thermal networks endows the 95-μm-thick composite film with the synergy of favorable EMI SE (∼15.8 dB) in the X band and impressive in-plane thermal conductivity (3.31 W/mK, enhanced by ∼2365%). Moreover, this multilayered architecture realizes multiple internal reflection-absorption of microwaves and efficient heat dissipation, while confers the film with advantageable flame retardancy and significant water resistance. Therefore, sPVA-based composite films from MS provide a promising solution for the development of multifunctional polymeric materials tailored for upcoming electronic devices in challenging environments.

SiC skeleton‐reinforced highly oriented graphite with good thermophysical and electromagnetic shielding properties

AbstractThe design of multifunctional materials with good thermophysical and electromagnetic shielding properties is desirable to overcome overheating and electromagnetic interference (EMI) in electronic devices. In this study, three‐dimensional (3D) continuous SiC skeleton‐reinforced highly oriented graphite flake (GF@SiC) composites were fabricated by combining molten salt synthesis, heat treatment, and spark plasma sintering. When the SiC content was higher than 9 vol.%, a 3D continuous SiC skeleton was formed, which effectively constrained the cross‐plane thermal expansion of the GF@SiC composites. Highly oriented GFs endowed the composites with good thermal conductivity (TC) along the basal plane and effective EMI shielding in the X‐band. The composites with SiC concentrations of 9 vol.% exhibited an optimal comprehensive performance with a high TC of 322 W/m/K in the basal plane direction, a low thermal expansion value of 10.5 × 10−6/K in the through‐plane direction, and EMI shielding effectiveness of 36 dB. Our strategy provides a promising and practical approach for realizing graphite‐based composites to meet the current demands for electronic devices.

An ultrathin and flexible polymer composite film at a low fraction of reduced graphene oxide for Ku-band electromagnetic interference shielding

The development of effective electromagnetic interference (EMI) shielding materials has turned into an extremely important and urgent challenge. The current study presents an ultrathin and flexible polymer, poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) composite thin film, at a very low loading of reduced graphene oxide (rGO) prepared by a straightforward solvent casting approach for efficient EMI shielding application. The homogenous distribution of rGO sheets throughout the polymer matrix has been verified by applying high-resolution scanning and transmission electron microscopy. To clarify the interfacial relationship between the matrix and filler as well as potential changes in phase, the PVDF-HFP/rGO (PrGO) composite films are further analyzed using X-ray diffraction, Raman spectra, Fourier transform-infrared spectra, and contact angle analysis. The PrGO composite film has a 4.2 GPa Young's modulus and a tensile strength of around 64.8 MPa. The Ku-band frequency has been implemented to evaluate PrGO composite films' EMI shielding ability. The ultrathin PrGO composite film (∼80 µm) revealed an efficient EMI shielding effectiveness (SE) of ∼18.3 dB at a meagre rGO fraction (6.75 wt.%). This efficient EMI SE from ultrathin PrGO composite films is due to the well-connected network of rGO sheets inside the PVDF-HFP matrix. This study demonstrates a scalable and effective way to design an ultrathin, lightweight, and flexible composite film for promising EMI shielding applications in the development of miniaturized electronic devices, and aerospace fields.

Strong Electromagnetic Interference and Protection in UAVs

With the proliferation of unmanned aerial vehicles (UAVs) and the escalating electromagnetic environment in space, there has been growing attention and research focus on the strong electromagnetic effects and electromagnetic protection design of UAVs. This paper aims to introduce the potential strong electromagnetic interference that UAVs may encounter during flight. It specifically concentrates on three crucial subsystems: the datalink system, the flight control and navigation system, and the power system. The goal is to provide an overview of the current state of research on the strong electromagnetic effects of UAVs, along with a discussion of commonly employed research methods. Additionally, this paper introduces various means of strong electromagnetic protection that can be utilized for UAVs. Finally, it concludes with a summary of the research status and development trends concerning the effects of strong electromagnetic interference and the corresponding protection measures for UAVs.

Electromagnetic Susceptibility Analysis of the Operational Amplifier to Conducted EMI Injected through the Power Supply Port.

Operational amplifiers (op-amps) are widely used in circuit systems. The increasing complexity of the power supply network has led to the susceptibility of the power supply port to electromagnetic interference (EMI) in circuit systems. Therefore, it is necessary to investigate the electromagnetic susceptibility (EMS) of op-amps at the power supply port. In this paper, we assessed the effect of EMI on the operational performance of op-amps through the power supply port by a bulk current injection (BCI) method. Firstly, we conducted the continuous sine wave into the power supply port by a current injection probe and measured the change in the offset voltage under EMI. Secondly, we proposed a new method of conducted susceptibility and obtained the susceptibility threshold regularities of the op-amps at the power supply port under the interference of different waveform signals. Our study provided conclusive evidence that EMI reduced the reliability of the op-amp by affecting the offset voltage of op-amps and demonstrated that the sensitivity type of op-amps was peak-sensitive at the power supply port. This study contributed to a deep understanding of the EMS mechanism and guided the design of electromagnetic compatibility (EMC) of op-amps.

Enhancing the Electromagnetic Shielding Effectiveness of Alumina (AL2O4) by Coating with Nano Gold (AuNp)

With the rapid development of Industry 4.0 and 5G technologies, new challenges are emerging and among them is electromagnetic interference (EMI). EMI may not only affect the performance of the devices operating around it but can also harm human health. Therefore, the issue of EMI shielding is becoming increasingly relevant. EMI shielding is most effectively achieved by using materials with high surface conductivity. This theoretical starting point provided the motivation to increase surface conductivity. To achieve this, in this study, electromagnetic shielding effectiveness (SE) of pure alumina (Al2O4) and nanogold-coated alumina is investigated, with the aim of enhancing the understanding of effective EMI shielding strategies.Through a series of carefully designed experiments and in-depth analysis, a significant finding emerges: nanogold-coated Al2O4 exhibits superior shielding performance, surpassing the effectiveness of its pure counterpart. The study evaluates key SE factors, including reflection loss and absorption loss, and highlights the remarkable improvement achieved by applying nanogold coatings to the aluminium oxide surface. In addition, this research also pioneers the combination of SE assessment with material characterization using cutting-edge techniques such as energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM) and X-ray diffraction (XRD). This multidisciplinary approach provides valuable insights into the electromagnetic interaction mechanisms responsible for the enhanced shielding performance of nanogold-coated AL2O4. The results of this study emphasize its potential significance in modern electronic systems, while also highlighting the lack of existing studies that combine SE evaluation with comprehensive material characterization, thereby contributing to the advancement of electromagnetic shielding research.

Synthesis of nickel particles for use in nickel/silicone rubber composites for the application of electromagnetic interference shielding gaskets

The effectiveness of electromagnetic interference (EMI) shielding is valuable for construction materials and can be enhanced by the addition of nickel particles to silicone rubber. This investigation reports the chemical reduction process employed to produce nickel powders. The resulting powders were analyzed through SEM imaging and X-ray diffraction analysis, which indicated the production of crystalline, pure nickel powders with spherical morphology. Subsequently, the study delves into nickel filler content enhances the shielding effectiveness (1.2–2.6 GHz) of gaskets by increasing the absorption loss SEA, due to the increase in electrical conductivity. The experimentation was conducted using three samples, revealing that increasing the weight percentage of filler from 30 to 70 % resulted in a considerable reduction in electrical resistivity to 0.6 Ω cm. Moreover, the shielding effectiveness was observed to increased to above 55 dBm when tested across a frequency range of 1.2–2.6 GHz.

Scalable synthesis of high-quality, reduced graphene oxide with a large C/O ratio and its dispersion in a chemically modified polyimide matrix for electromagnetic interference shielding applications.

High-purity reduced graphene oxide (RGO or rGO) with appreciable conductivity is a desired conductive filler for lightweight polymer composites used in coatings, electronics, catalysts, electromagnetic interference (EMI) shielding, and energy storage devices. However, the intrinsic conductivity and the uniform dispersion of RGO in relatively polar matrices are challenging, leading to poor overall conductivity and performance of the composite material. The reported study improved the RGO intrinsic conductivity by increasing its C/O ratio while also simultaneously enhancing its compatibility with the polyimide (PI) matrix through ester linkages for better dispersion. A two-step reduction method drastically increased the number of structural defects and carbon content in the resulting RGO, corresponding to a maximum ID/IG and C/O of 1.54 and ∼87, respectively. Moreover, the 2D nanosheets with limited hydroxyl (-OH) groups effectively interacted with anhydride-terminated polyamic acid (AT-PAA) through chemical linkages to make high-performance RGO/PI nanocomposites. Consequently, the polymer matrix composites possessed the highest direct current conductivity of 15.27 ± 0.61 S cm-1 for 20 wt% of the prepared RGO. Additionally, the composite material was highly stiff (3.945 GPa) yet flexible (easily bent through 180°), lightweight (∼0.34 g cm-3), and capable of forming thin films (162 ± 15 μm). Unlike most polymer matrix composites, it showcased one of its class's highest thermal stabilities (a weight loss of only 5% at 638 °C). Ultimately, the composite performed as an effective electromagnetic interference (EMI) shielding material in the X-Band (8 to 12 GHz), demonstrating outstanding shielding effectiveness (SE), shielding effectiveness per unit thickness (SEt), specific shielding effectiveness (SSE), and absolute shielding effectiveness (SSEt) of 46 dB, 2778 dB cm-2, 138 dB cm3 g-1, and 8358 dB cm2 g-1, respectively. As a consequence of this research, the high-purity RGO and its high-performance PI matrix nanocomposites are anticipated to find practical applications in conductive coatings and flexible substrates demanding high-temperature stability.

General issues of ensuring electromagnetic compatibility of aircraft on-board equipment

The article examines the effect of electromagnetic interference on the electrical components of the aircraft from the point of view of external and internal electromagnetic environments. The external electromagnetic environment consists of high-intensity radiated fields and lightning strikes. Internal threats can be divided into four types: intersystem, intra-system, induced radiated fields of high intensity and internal transients during a lightning strike. On the basis of the considered impact, the article defines the directions of development in the field of providing electromagnetic compatibility for an all-electric aircraft.

Highly effective EMI shielding composites for 5G Ka-band frequencies

Reliable electromagnetic interference (EMI) shielding is essential to secure communications, protect components, and ensure efficient 5G network operation as these technologies expand. In this investigation, we propose a composite material that demonstrates remarkable EMI shielding efficacy, particularly within the Ka-band frequency range (26–40 GHz). This material is practical for industrial fabrication because it can be readily produced by integrating carbonyl iron powder (CIP) and carbon fabric (CF) into a polydimethylsiloxane matrix. It achieves a high shielding effectiveness of at least 120 dB within the Ka-band range, which can be further increased to an ultra-high level of 160 dB by adjusting the CF content. Electromagnetic analyses reveal that this enhanced shielding efficiency is due to the synergistic interplay between multiple reflections of incident EM waves within the CF structure and the excellent EM wave absorption properties of CIP. This composite material not only enhances EM shielding efficiency but also provides enhanced mechanical strength and thermal conductivity, rendering it a practical choice for EM shielding applications in the 5G Ka-band frequency range.

Investigation on high EMI shielding effectiveness and shielding mechanism of spherical Ti3C2Tx microfilm prepared by spray-freezing

Due to the explosive growth of the number of miniature electronic devices in the 5 G era, higher requirements have been raised for electromagnetic pollution protection materials. The production of effective electromagnetic (EM) interference (EMI) shielding materials is still challenging. In this research, Ti3C2Tx microspheres were successfully synthesized by the self-developed spray freezing technology and 43 µm-thick spherical Ti3C2Tx microfilm was prepared by vacuum filtration. The spherical film can block 5 G communication signals and its EMI shielding effectiveness (SE) is 51 dB, which is 50% higher than that of the 2D Ti3C2Tx film of approximately the same thickness. Additionally, the effects of transmitting X-band EM waves through a 43 µm-thick spherical Ti3C2Tx sheet were simulated employing Comsol Multiphsics. It is found that an annular current traveling perpendicular to the direction of electromagnetic wave propagation will be induced in the spherical Ti3C2Tx, which leads an extra larger EM loss. This discovery provides a novel avenue for the structural design of EMI shielding materials.

Analysis of Electromagnetic Interference Effect on Semiconductor Scanning Electron Microscope Image Distortion

Most electronic devices are susceptible to electromagnetic interference (EMI); thus, it is necessary to recognize and identify the cause and effect of EMI as it can corrupt electronic signals and degrade equipment performance. Particularly, in semiconductor manufacturing, the equipment used for image capturing is subject to various noises induced by EMI, causing the image analysis to be unreliable during the image recognition and digitization process. Thus, in this research, we aim to detect and quantify the influence of EMI on semiconductor SEM (scanning electron microscope) images. For this, we apply several useful denoising and edge detection techniques to find a clearer distorted shape from EMI-generated images and then compute five shape-related measures to evaluate the distortion. From a comprehensive experimental analysis and statistical tests, it is found that the medians of all the extracted shape-related measures of high-EMI SEM images are higher than those of both medium- and weak-EMI SEM images, and also all the p-values of the statistical tests are close to 0, and thus we can conclude that all the measures are good quantification metrics for assessing the impact of EMI on semiconductor SEM images.