Electromagnetic Interference Research Articles

Eliminating electromagnetic interference for RF shielding-free MRI via k-space convolution: Insights from MR parallel imaging advances.

Recent advances in ultra-low field MRI have attracted attention from both academic and industrial MR communities for its potential in democratizing MRI applications. One of the most striking features on those advances is shielding-free imaging by actively sensing and eliminating the electromagnetic interference (EMI). In this study, we review the analytical approaches for EMI estimation/elimination, and investigate their theoretical basis and relations with parallel imaging reconstruction. We provide further understanding of the existing approaches, formulating EMI estimation as convolution in k-space or multiplication in spectrum-space. We further propose to use tailored convolutional kernel to adaptively fit the varying EMI coupling across the acquisition window. These methods were evaluated with both simulation study and human brain imaging. The results show that using tailored convolutional kernel can achieve more robust performance against system and acquisition imperfections.

Space vector pulse width modulation realization for three-phase voltage source inverter

This paper presents the implementation of space vector pulse width modulation (SVPWM) for a three-phase voltage source inverter (VSI). SVPWM is a technique used to control the output voltage of VSIs with improved efficiency and precision. The abstract outlines the key steps involved in implementing SVPWM, including reference signal clarification, sector identification, determination of voltage vectors, and switching state calculation. This proposed system provides improved output voltage of the inverter, minimized voltage stress across the switches and reduced total harmonic distortion and electromagnetic interference. The proposed implementation aims to enhance the performance of three-phase VSIs in various applications, such as motor drives, renewable energy systems, and power converters. The simulation results of proposed system are verified using MATLAB Simulink.

Poly aryletherketone chemically modified multi-walled carbon nanotubes/poly etheretherketone electromagnetic interference shielding foam suitable for high temperature and strong corrosive media

Poly aryletherketone chemically modified multi-walled carbon nanotubes/poly etheretherketone (PAEK-m-CNTs/PEEK) electromagnetic interference (EMI) shielding foams were fabricated using supercritical carbon dioxide (Sc-CO2) foaming technique saturated near-melting point (Tm). The percolation thresholds for conductivity and EMI shielding of PAEK-m-CNTs/PEEK foams were both significantly reduced by the presence of the porous structure, reaching to 0.0457 vol% and 0.123 vol%, respectively. These reductions were observed to be 87.72% and 75.20% of those of PAEK-m-CNTs/PEEK composites. This could be attributed to the heterogeneous nucleation of PAEK-m-CNTs, which are uniformly dispersed in PEEK, in addition to the Sc-CO2 foaming technique saturated near Tm. By comparison, it could be observed that the specific total electromagnetic shield effectiveness (SSETotal) of PAEK-m-CNTs/PEEK foam with a filler content of 0.440 vol% was 687.9% higher than that of PAEK-m-CNTs/PEEK composite with a filler content of 0.496 vol%. Moreover, the introduction of the porous structure transformed the electromagnetic shielding material from reflective to absorptive. In addition, PAEK-m-CNTs/PEEK foams demonstrated the capacity to maintain stable performance even in high temperatures of up to 315 °C and in the presence of strong corrosive media.

Enhancement of liner materials based on nanomaterials to promote sustainability in noise intercourse

Daily usage of devices has had a major influence on lives and existence, which would be unimaginable without them. Due to this, recent gadget dependability concerns need particular attention. PCs, hand mobile phones, and other computerized household gadgets need integrated circuits (ICs). Individual components must work together to accomplish their tasks and make the circuit operate. Hot carrier effect, oxide breakdown, and other system-level problems result from accommodating several devices in a planar IC. Vertical linking active components in one IC to another IC is a common method of three-dimensional IC integration (3D-IC). The main issue with 3D-IC adoption is electrical interference to neighboring through silicon via (TSV) and active transistors, which substantially reduces system performance. The electrical TSV (ETSV) model, which employs solely electrical signal carrying TSV, and the thermal TSV (TTSV) model, which incorporates thermal TSV during simulation, are used in this research to reduce electrical interference. The electrical signal transporting TSV to the substrate and other TSV was investigated for interference. With other models, this study also shows higher frequency regimes up to 1 THz. We found that the suggested methodology improves 3D-IC development by more than 30% by reducing electrical interference from signal-carrying TSV to other TSV.

“Rigid-Flexible” structured polyimine/graphite felt composites with excellent fire Resistance, electromagnetic shielding and recyclability

With the development of the electronic information, the conductive polymers with high electromagnetic interference (EMI) shielding effectiveness has become a research point. The polyimine material that forms a cross-linking network can rapidly achieve bond exchange at high temperatures, which is becoming a potential substrate for carbon loaded materials. In this work, a novel composite material is successfully prepared by incorporating cost-effective graphite felt (GF) with excellent electrical properties into a biobased polyimine network. Leveraging the exchange properties of dynamic imine bond (−C = N-), the two substrates can be separated by acidolysis, enabling a recycle of the GF efficiently. The electromagnetic shielding effectiveness (EMI SE) of the composite material in the X-band (8.2–12.4 GHz) reaches approximately 46 dB. Additionally, the introduction of highly fire-resistant graphite material significantly enhances the flame retardancy of the composite by reducing the peak heat release rate (HRR) by 47.1 %, which improves the fire safety in complex electromagnetic environments. Herein, we broaden the application of polyimine/graphite composites in the electronic information field and provide a new strategy for the preparation of environmentally friendly composite materials.

Flexible and durable shape memory EVA/MXene/EVA fiber membrane for programmable EMI shielding

Flexible and lightweight electromagnetic interference (EMI) shielding materials are currently the focus of electromagnetic protection material research. By applying shape memory polymers to the field of electromagnetic shielding, intelligent electromagnetic shielding composites with programmable shielding performance can be prepared. In this study, a flexible EVA/MXene/EVA electromagnetic shielding composite membrane with programmable shielding effectiveness was prepared using electrospinning, vacuum filtration, and hot pressing techniques. Even with a low MXene content, the EMI shielding effectiveness in the X-band still achieved 40.5 dB, and the specific EMI shielding effectiveness was as high as 6.23 × 103 dB cm2 g−1. The composite membrane exhibited excellent shape memory performance, with a shape fixation rate (Rf) of 93.8 % and a shape recovery rate (Rr) of 92.1 %, achieving a programmable shielding effectiveness of 14.1–40.5 dB under 0–30 % tensile strain. Additionally, the composite membrane could serve as a switch for electromagnetic shielding, controlling the reception and shielding of electromagnetic waves. Simultaneously, the composite membrane exhibits excellent hydrophobicity, electrothermal conversion capability, and durability. Importantly, it retains almost the same shielding effectiveness even after undergoing 500 cycles of bending and folding, as well as prolonged exposure to strong acids and alkalis. This work not only offers new insights into the development of multifunctional and intelligent electromagnetic shielding composites suitable for harsh environments but also expands the application scope of shape memory smart materials.

Ag@MXene-cellulose nanofiber composite for electromagnetic interference shielding, sensing, and actuating

With the development of flexible electronic devices, the development of flexible and multi-functional materials becomes increasingly important. In this study, we prepared Ag@MXene-cellulose nanofiber (AMC) multi-functional composites with a three-dimensional (3D) conductive network structure, which can be used for electromagnetic interference (EMI) shielding, pressure sensing, and actuating. AMC has good electrical conductivity (18.04 S cm-1) and EMI shielding effectiveness (37.7dB). The microstructure of the AMC surface gives it the potential to be applied in the pressure sensor. AMC is humidity-sensitive and has excellent electrical/photo-thermal conversion properties. Thus, AMC can be used to fabricate humidity-driven actuators and electrical/light-driven actuators. Finally, three multi-functional devices/systems have been carefully designed to achieve the fabrication of multi-functional devices/systems that rely on only one raw material, which significantly simplifies the preparation of multi-functional devices. We hope this research will open up new ways for artificial muscles, soft robots, and EMI shielding devices.

Review of EMC standards for Underwater Vehicles

Electromagnetic Compatibility (EMC) is a critical consideration in the design and manufacturing of any kind of automobile, including underwater vehicles like Remotely Operated Vehicles (ROV) and Autonomous Underwater Vehicles (AUV), to ensure their proper functioning and to prevent Interference with other equipment. The purpose of this paper is to understand the significant importance attached to the Electromagnetic Compatibility (EMC) concept in the design and manufacturing of underwater vehicles such as Remotely Operated Vehicles (ROVs) and Autonomous Underwater Vehicles (AUVs). It critically reviews available standards concerning Electromagnetic Compatibility (EMC) for these vehicles while pointing out some of the many sources of Electromagnetic Interference (EMI) within the surroundings and the geography, such as the sea. This research makes it clear that optimum performance and lack of Interference with other marine systems are only realizable with the use of necessary EMI requirements. This paper comprehensively explores the existing and diverse EMC standards applicable to underwater Vehicles.

MXene@Wood composite with absorption-dominated electromagnetic interference shielding performance through structural modification

Wood-based materials possess unique porous structure that are sustainable and green, showing great potential in many applications. Herein, MXene@Wood composites were prepared for electromagnetic interference shielding and thermal insulation, and their pore structure is monitored by compression of wood. Benefiting from the heterogeneous interface between MXene and the wood surface to enhance interfacial polarization, MXene@Wood presents a superior impedance match in cross-section compared to tangential-section. In the cross-section, MXene@Wood at a 30 % compression ratio achieves an absorption coefficient of 0.73 and a shielding effectiveness of 41.78 dB. After a 30 % compression ratio, MXene@Wood in cross-section achieves an absorption coefficient of 0.73 and a shielding effectiveness of 41.78 dB, it also exhibits wave absorption performance with a minimum reflection loss of −15.11 dB at 2 mm, meeting the commercial requirements. The effect of the pore structure of wood on shielding performance is further verified by finite element analysis. Furthermore, MXene@Wood also demonstrates excellent thermal insulation properties benefit to the reduced gas-phase heat transfer. This sustainable composite with electromagnetic shielding performance and thermal insulation properties largely expands the application area of wood.

Investigation of Electromagnetic Wave Absorption Properties of Ni-Co and MWCNT Nanocomposites.

In recent years, severe electromagnetic interference among electronic devices has been caused by the unprecedented growth of communication systems. Therefore, microwave absorbing materials are required to relieve these problems by absorbing the unwanted microwave. In the design of microwave absorbers, magnetic nanomaterials have to be used as fine particles dispersed in an insulating matrix. Besides the intrinsic properties of these materials, the structure and morphology are also crucial to the microwave absorption performance of the composite. In this study, Ni-Co- MWCNT composites were synthesized, and the changes in electric permittivity, magnetic permeability, and reflectance loss of the samples were evaluated at frequencies of 2 to 18 GHz. Nickel-Cobalt-Multi Wall Carbon Nanotubes (MWCNT) composites were successfully synthesized by the co-precipitation chemical method. The structural, morphological, and magnetic properties of the samples were characterized and investigated by X-ray diffractometer (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Vibrating Sample Magnetometer (VSM), and Vector Network Analyzer (VNA). The results revealed that the Ni-Co-MWCNT composite has the highest electromagnetic wave absorption rate with a reflectance loss of -70.22 dB at a frequency of 10.12 GHz with a thickness of 1.8 mm. The adequate absorption bandwidth (RL <-10 dB) was 6.9 GHz at the high-frequency region, exhibiting excellent microwave absorbing properties as a good microwave absorber patent. Based on this study, it can be argued that the Ni-Co-MWCNT composite can be a good candidate for making light absorbers of radar waves at frequencies 2- 18 GHz.

Structural-Functional Integrated Graphene-Skinned Aramid Fibers for Electromagnetic Interference Shielding.

Structural-functional integrated polymer fibers with exciting properties are increasingly important for next-generation technologies. Herein, we report the structural-functional integrated graphene-skinned aramid fiber (GRAF) featuring high conductivity, high strength, and light weight, which is weaved for efficient electromagnetic interference (EMI) shielding. Graphene was self-assembled onto the surface of aramid fibers through a dip-coating strategy using an aramid polyanion (APA) as the binder and the etchant. The molecular dynamics (MD) simulation results show that the binding energy of the APA-modified aramid chain and graphene (1.3 J/m2) is superior to that of the aramid chain and graphene (0.2 J/m2). The APA has a higher surface energy (55.2 mJ/m2) and can etch the fiber surface, forming grooves, which enables effective adsorption and self-assembly of graphene onto the fiber surface. The GRAF exhibits a high conductivity of 1062.04 ± 116.78 S/m, along with excellent strength (4.66 ± 0.16 GPa) and modulus (106.33 ± 8.21 GPa), outperforming most reported conductive composite fibers (e.g., natural fibers, polymer-based fibers, inorganic fibers, etc.). The weaved functional fabric using the structural-functional integrated GRAF shows an EMI shielding efficiency (SE) of up to 67.86 dB in the X-band and can rapidly heat up to 200 °C within 40 s at 12 V voltage. In addition, the GRAF fabric can maintain its electrical conductivity after a long-term washing, showing excellent washing resistance. This study demonstrates an effective method to fabricate structural-functional integrated materials and shows the promise of carbonene fibers for EMI shielding.

Electrical stimulation methods for scoliosis in children: a literature review

Introduction. Scoliosis is one of the most common orthopedic diseases of childhood and adolescence, leading to disability and reducing the child’s quality of life. The prevalence of scoliosis in the structure of pediatric orthopedic pathology reaches 30 %. In 50 % of cases, the disease is characterized by a severe progressive course, especially during puberty. Aim. Studying the effectiveness of electrical stimulation methods for scoliosis in children to develop recommendations for their practical use based on the analysis of systematic reviews and randomized controlled trials. Materials and methods. The search was carried out using the database of evidence-based physiotherapy PubMed, Cyberleninka and eLIBRARY using the keywords: «electrical stimulation», «pulse currents», «scoliosis», «children» for the period from 2008–2024.Exclusion criteria: articles published on this topic before 2008. Main content. The main methods of physiotherapy used in the treatment of scoliosis in children are electrotherapy methods, among which electrical stimulation plays a leading role. The advantage of electrical stimulation for scoliosis in children is to provide training in the strength and tone of the back muscles on the side of the deformity. Electrical stimulation is indicated for scoliosis of I and II degrees. The greatest effect in the correction of scoliotic spinal deformity in children is observed with the combined use of electrical stimulation and exercise therapy. This review provides data on the relevance of medical rehabilitation of scoliosis in children, the mechanism of action of electrical stimulation, data on the effectiveness of using electrical stimulation methods for scoliosis in children: sinusoidal modulated currents, diadynamic therapy, transcutaneous electrical neurostimulation, interference therapy, fluctuarization and functional programmable electrical stimulation. Conclusion. Currently, a wide range of electrical stimulation technologies has been developed for the medical rehabilitation of children with scoliosis, among which sinusoidally modulated currents and diadynamic currents are most often used. Transcutaneous electrical neurostimulation, having a predominantly antinociceptive effect, also has an effect on muscle contractions. Functional programmable electrical stimulation of muscles is a promising technology for medical rehabilitation of children with scoliosis, requiring further study and scientific justification.

Effect of silane-functionalized green synthesized silver nanoparticle, ferrite, and silk microfiber epoxy composite on electromagnetic interference shielding

Effect of silane-functionalized green synthesized silver nanoparticle, ferrite, and silk microfiber epoxy composite on electromagnetic interference shielding

Software Define Wide Area Network (SDWAN) network optimization analysis on radiolink-fiber optic access media migration

The development of technology in radiolink networks has grown rapidly and is suitable to be implemented on wide coverage area networks, but weather and physical environment factors greatly affect signal conditions. The background that has been stated, this study proposes migration to fiber optic access media because it is able to send data faster and is not affected by electromagnetic interference and is stable. Furthermore, this study conducted an optimization analysis on the SDWAN (Software Defined Wide Area Network) network, SDWAN functions as a firewall that can provide connectivity support and infrastructure network development in branch offices with system security in one centralized platform. The test method used in this study is a connectivity test from each remote fortigate located in the branch office. While the analysis method used is Quality of Service (QoS), which is a method to find out data delivery (Packet Loss, Delay and Jitter) using the FortiManager application, which is the analytical and experimental proof of concept of the SDWAN network model using the BGP method for auto failover testing.

Overview of Key Techniques for In Situ Tests of Electromagnetic Radiation Emission Characteristics

With the growing number of electronic devices loaded and increasing influence from electromagnetic interference, large-scale systems or platforms are confronted with increasingly severe electromagnetic compatibility challenges. Due to the vast size of these systems and the multitude of electronic devices they contain, standard laboratory environments are often inadequate for meeting test requirements. This paper reviews the state-of-art in the area of field measurement techniques related to the checking of electromagnetic compatibility, and the key technologies of electromagnetic interference filtering and wide-bandwidth, large-dynamic, and rapidly transient signal extraction in the measurement field are analyzed. The research status of electromagnetic interference suppression, transient and broadband measurement, and environmental interference suppression combined with time-domain fast measurement and other technologies are summarized and analyzed. Based on a comparative analysis of the aforementioned technologies, the future development trends of field measurement technology are also discussed.

Zeolitic Imidazolate Frameworks Derived Magnetic Nanocage/MXene/Nanocellulose Bilayer Aerogels for Low Reflection Electromagnetic Interference Shielding and Light‐to‐Heat Conversion

AbstractTo cope with the increasingly serious electromagnetic pollution, the demand for electromagnetic interference (EMI) shielding materials with low electromagnetic wave reflection ability has become urgent. Controlling electrical components, magnetic components, and designing the EMI material structure can effectively improve electromagnetic shielding performance, but this remains a significant challenge. Besides, extreme cold weather conditions also do considerable potential damage to the normal work of outdoor electronic equipment. Integrated light‐to‐heat conversion capability on electromagnetic shielding materials can further improve the stability and reliability of the equipment. Herein, the novel bilayer aerogels composed of zeolitic imidazolate frameworks derived hollow CoNi carbon nanocage/MXene Ti3C2Tx/nanocellulose (BZMN) are prepared by a two‐step freezing method. BZMN aerogels exhibit good EMI shielding effectiveness (SE) with low reflection coefficient (R coefficients): 35.1 dB (R coefficient = 0.28) and 21.2 dB (R coefficient = 0.25). The unique structures of bilayer aerogels demonstrate the ability to absorb more electromagnetic waves through interfacial polarization and multiple scattering. The green shielding index (gs) of BZMN aerogels can reach 2.88. Moreover, BZMN aerogels show remarkable and unique light‐to‐heat conversion performance on different surfaces. Under 2.0 sun intensity, temperatures can reach 109.3 °C in the upper layer and 102.3 °C in the lower layer. Under 0.8 W cm−2 near‐infrared (NIR) laser intensity, the temperatures can rise to 234.1 °C in the upper layer and 167.4 °C in the lower layer. In addition, the size and shape of BZMN aerogels can be customized according to the mold. These features present BZMN aerogels as advanced potential low reflection EMI shielding device candidates, useful for future telecommunication and electronic equipment protection.

Regulating the Conductive Network of Graphene/Ni Composite Films toward Tunable Electromagnetic Shielding Efficiency.

Smart electromagnetic interference (EMI) shielding materials with adjustable shielding efficiency (SE) hold immense importance in the field of wearable and switchable EMI shielding. However, existing materials often suffer from a constrained tunability range and inadequate stability. In this study, a highly stretchable conductive framework is fabricated by integrating Ni-doped laser-induced graphene (LIG/Ni) with silicone. Through meticulous manipulation of the LIG scanning trajectory and Ni nanoparticle (NP) deposition parameters, ordered and dense conductive pathways were formed. This ordered structure preserves the graphene's structural coherence and conductivity along the axis perpendicular to stretching, while graphene parallel to the stretching direction forms random connections, resulting in the effective regulation of electrical conductivity. Under a 200% strain, the electrical conductivity dropped to a minimum of 1.07 S/cm, and the average SE in the X-band was reduced to 2.33 dB. Upon strain release, the conductive network rapidly reconfigured, boosting conductivity to 63.6 S/m and an enhanced SE of 68.12 dB. With its highly reversible conductive network, this composite exhibits exceptional cycling stability and an expansive range of adjustable SE, thereby holding immense practical value for versatile electromagnetic protection applications.

Carbonized Apples and Quinces Stillage for Electromagnetic Shielding

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.

The Breakthrough Listen Search for Intelligent Life: Galactic Center Search for Scintillated Technosignatures

The search for extraterrestrial intelligence at radio frequencies has focused on spatial filtering as a primary discriminant from terrestrial interference. Individual search campaigns further choose targets or frequencies based on criteria that theoretically maximize the likelihood of detection, serving as high-level filters for interesting targets. Most filters for technosignatures do not rely on intrinsic signal properties, as the radio-frequency interference (RFI) environment is difficult to characterize. In B. Brzycki et al. (2023), we proposed that the effects of interstellar medium (ISM) scintillation on narrowband technosignatures may be detectable under certain conditions. In this work, we perform a dedicated survey for scintillated technosignatures toward the Galactic center and Galactic plane at the C band (3.95–8.0 GHz) using the Robert C. Byrd Green Bank Telescope (GBT) as part of the Breakthrough Listen program. We conduct a Doppler drift search and directional filter to identify potential candidates and analyze results for evidence of scintillation. We characterize the C-band RFI environment at the GBT across multiple observing sessions spread over months and detect RFI signals with confounding scintillation-like intensity modulation. We do not find evidence of putative narrowband transmitters with drift rates between ±10 Hz s−1 toward the Galactic center, ISM-scintillated or otherwise, above an equivalent isotropic radiated power of 1.9 × 1017 W up to 8.5 kpc.

Design and simulation of reconfigurable modular snake robots with bevel gear transmission

With the advancement of technologies, robotics is playing an increasingly important role in various fields. The snake robot has attracted widespread academic attention due to its efficient and flexible movement characteristics. Nevertheless, its popularity and application range are constrained by complex control, low durability, and high cost. Given this, this study proposed a modular design framework based on the concept of modular design and a reconfigurable modular snake robot using bevel gear transmission. The snake robot consists of several basic module units with the same structure, which are restructured and reconfigured to achieve different shapes and functions. A standardized interface and communication protocol were optimized and designed, with each module containing an autonomous control unit and several execution units. The robot realized motion and tasks through the collaborative work of multiple modules to adapt to various work and environmental requirements. In addition, the research analyzes distributed control, improved motion control (using PID algorithm), energy management, safety design and other aspects, based on the cost data, improvement measures were proposed. At the same time, the work risks of the robot are analyzed, such as mechanical damage to the human body, adverse environment and electromagnetic interference, and corresponding solutions are proposed, and problems are found through durability testing and material improvement measures are proposed. Finally, based on SolidWorks software, a three-dimensional modeling and simulation analysis was conducted on the robot to verify its correctness. This study can provide inspiration for the design and research of snake robots.