The rapid evolution of intelligent electromagnetic systems has heightened the performance standards for observation windows, driving a demand for flexible, multifunctional, transparent EMI shielding films with robust environmental durability, while current progress remains a significant challenge. In this study, a multifunctional transparent EMI shielding film composed of silver nanowire (AgNW) and polydimethylsiloxane (PDMS) with an embedded conductive network was fabricated via a two-step process involving rotational spraying followed by infiltration transfer. The resulting AgNW/PDMS film exhibits high optical transmittance (71.1%) and low sheet resistance (11.3 Ω/sq), combined with average EMI shielding effectiveness (EMI SE) of 30.2 dB in the X-band, 32.6 dB in the Ku-band, and 34.5 dB in the K-band. The synergistic effect of PDMS-induced physical confinement and hydrogen bonding markedly enhances the interfacial adhesion and antioxidant capacity of the transparent shielding film, contributing to the reliability and durability in harsh environments. Simultaneously, the strain-induced reconfiguration of the AgNW network and the resultant adaptive conductivity modulation synergistically enable the film to exhibit exceptional strain-sensing performance and efficient Joule heating functionality. The multifunctional integration clearly demonstrates that transparent shielding films possess significant potential for enabling iterative improvements in observation window systems across aerospace, automotive, and next-generation electronic device applications.

As a rigorous and comprehensive foundation for electromagnetic information theory (EIT), we develop a general theory that elucidates the universal stochastic structure of radiated electromagnetic (EM) fields and induced currents in generic EM information transmission systems. The framework encompasses arbitrary random scatterers, input information fields, and EM mutual coupling. The system is modeled as a multiply connected, arbitrary Riemannian manifold within the language of differential geometry. Our approach exploits exact Green’s functions (GFs) on manifolds to construct a novel electromagnetic random field theory (EM-RFT). Interpreted as response functions localized on the surfaces of transceivers and scatterers, the GFs allow us to treat the internal physical details of the EM system as a black box, redirecting analytical attention toward external input–output relations in line with signal processing and communication theory. This integration of random fields (RFs), electromagnetics, and GFs yields a unified framework for deriving and characterizing the stochastic structure of arbitrary EM information transmission systems. We rigorously establish that EM random fields satisfying Maxwell’s equations can always be constructed using system GFs driven by external information fields. The theory further decouples stochastic input RFs from random fluctuations associated with the communication medium (e.g., scatterers), and introduces general correlation propagators valid for arbitrary EM links. Using the Karhunen–Loève expansion, all EM random fields are represented as sums of random variables, providing both a simulation framework for arbitrary EM RFs and a basis for evaluating mutual information between input and output spatial domains at arbitrary locations in the system.

Monobloc frontofacial advancement (MFFA) is a key procedure for treating functional and morphological complications of syndromic craniofacial synostoses. Critical osteotomies -particularly the frontonasal cut and the pterygomaxillary disjunction - are technically demanding and often performed under limited visibility. Conventional intra-operative fluoroscopy improves accuracy but prolongs surgery and exposes both patient and staff to radiation. We report our initial experience using an electromagnetic (EM) neuronavigation system (Medtronic StealthStation EM) in three pediatric patients undergoing MFFA with distraction. Pre-operative CT-based trajectory planning guided the frontonasal osteotomy, distraction vector orientation, and safe placement of distractors. Intra-operatively, a handheld EM-tracked stylet provided real-time guidance of deep osteotomies and confirmed the completeness of pterygomaxillary disjunction without the need for intra-operative fluoroscopy. It enabled precise orientation of distraction vectors, verification of pterygomaxillary separation, and real-time adjustment of the frontonasal osteotomy. Morphological improvement was achieved in all patients: all three showed correction of pseudo-exorbitism, and one was weaned from tracheostomy. Obstructive sleep apnea syndrome improved in two patients, though one continues to require non-invasive ventilation. Electromagnetic neuronavigation proved to be safe, radiation-free, and particularly valuable for guiding complex osteotomies in MFFA. It may reduce operative time, improve vector-oriented distraction, and facilitate teaching of intricate surgical steps.

This paper explores advanced methods of electromagnetic (EM) waveform manipulation through temporally-modulated thin sheets. Two configurations are analyzed-a layer with time-varying (TV) conductivity and one with TV permittivity-to determine how temporal modulation of these parameters affects the transmission of incident EM pulses. Analytical and numerical approaches are formulated to solve the corresponding inverse problems, providing the required temporal profiles of material parameters for achieving user-defined transmitted waveforms. Several application examples are presented, including frequency mixing, time-domain (TD) pulse shaping, and spectral shaping, which demonstrate how dynamic control of a layer's conductance or capacitance can tailor the time-domain profile and spectral content of EM pulses. The results were validated using a commercial FEM code and show that a properly designed time variation of the layer's conductance or capacitance enables functions such as pulse compression, spectral reweighting, and generation of new frequency components, making such structures promising for advanced reconfigurable EM systems.

With the rapid development of 6G communication, optoelectronic integration, and advanced stealth technologies, electromagnetic functional materials are increasingly required to achieve collaborative broadband responses across microwave, terahertz, and optical bands, posing urgent demands for breakthroughs in multispectral electromagnetic response mechanisms and device innovation. This perspective systematically reviews the research advances in 2D electromagnetic materials and their derived multispectral devices, with a particular emphasis on elucidating the correlations between material structures, electromagnetic properties, and multispectral response behaviors. We systematically look ahead at the future development directions of multi-spectral electromagnetic responses and devices from five key aspects, encompassing cross-domain signal conversion systems, environment-driven full-spectrum adaptive reconstruction, interface polarization engineering of low-dimensional nanomaterials, cross-domain integration under extreme environments, and programmability of dynamic spectral responses. These guidelines are intended to lay a theoretical and technical foundation for advancing the development of next-generation intelligent electromagnetic systems, thereby facilitating their applications in fields such as communications, sensing, medicine, and national defense.

In this article, the motion control of ferromagnetic particles through varying a non-invasive magnetic field is addressed. Within an experimental test bench, three experiments are proposed to verify motion control, which consist of control of the distance between electromagnets, retention of particles over the flow, and manipulation of the direction of particle flow at a “Y”-type bifurcation emulating an “OR” gate. At each experimental stage, instrumented test benches were integrated with current, distance, and flow sensors, enabling measurement and feedback of the system’s physical variables. These benches were configured using pulse-width-modulation (PWM) and Proportional–Integral–Derivative (PID) controllers to regulate the current supplied to the electromagnets and, thereby, control the intensity of the induced electromagnetic field according to the requirements of each experiment. Different study cases were defined to analyze the operational limits of the system by varying the current influencing the electromagnetic field and the configuration of the electromagnets. The results describe the response of the magnetic field, the induced force, and the behavior of the suspended particles under each condition, providing elements to characterize the performance of the electromagnetic system in operational scenarios and contributing to the understanding of the phenomena associated with the non-invasive manipulation of ferromagnetic particles by means of controlled magnetic fields.

DefenDoor: An electromagnetic fingerprint-based access control system with forced-entry detection and SMS notification

Abstract The increasing demand for sustainable energy solutions necessitates replacing the traditional energy sources with renewable energy, particularly for realizing self-powered wireless sensor networks (WSNs) in railway transportation. This paper proposes a double-sided rack rail vibration energy harvesting system (DVHS) to harvest vibration energy generated by trains when they pass over the rail, providing electricity to the wireless sensor networks. The input mechanism, mechanical rectifier, power generation module, and adaptive interface circuit are designed for the proposed DVHS. The mechanical rectifier, composed of a double-sided rack and one-way bearing, is employed to change the railway vibration into rotation. Rotational energy is subsequently transmitted to the power generation module via a mechanical transmission device, converting the mechanical energy into electrical energy. Experimental results show that the DVHS generates an average power output of 854 mW with the vibration amplitude of 5 mm at 5 Hz. An adaptive interface circuit with the maximum energy conversion efficiency of 93.5 % is designed to efficiently extract energy from the vibration energy harvester and provide a stable output voltage. A 1.5 F supercapacitor can be fully charged by the DVHS within only 162 s, after which it powers the wireless sensing network for up to 300 s of continuous data transfer. The proposed DVHS presents a promising solution for sustainable condition monitoring in railway systems, reducing dependence on conventional power supplies.

Data-driven nonlinear system modeling is essential for capturing complex dynamics in real-world applications. However, accurately modeling these systems often requires a significant amount of high-quality measured data and frequent parameter updates, which can be both expensive and time-consuming. To address this challenge, this article proposes a novel tree-based, data-driven approach for approximating dynamic nonlinear systems using piecewise linearized deep random forests (PWLDRF). In each layer of the PWLDRF, we employ the Pareto principle to assign regression trees and random trees, enhancing intralayer diversity. Moreover, we utilize a layer-wise piecewise linear approximation to capture nonlinear dynamics. Specifically, piecewise breakpoints and affine targets are adaptively determined based on expected values derived from the current layer. This layer-wise forward learning mechanism not only simplifies the design of PWLDRF but also improves nonlinear modeling efficiency. Theoretical analysis demonstrates PWLDRF’s ability to approximate complex nonlinear systems with high accuracy. Experimental results on a benchmark nonlinear system and an electromagnetic suspension system show that PWLDRF achieves competitive accuracy compared to traditional neural network models while requiring significantly fewer training samples, thereby validating the effectiveness and data efficiency of the proposed method.

École Nationale Supérieure de Chimie de Paris, ParisTech, France 9–12 December 2025 The Conference on Research and Innovations in Science and Technology of Material 2025 (CRISTMas 2025) was held from 9 to 12 December 2025 at École Nationale Supérieure de Chimie de Paris, Paris, France. Organised by the STEMM Global Scientific Society, CRISTMas 2025 brought together researchers, engineers, and industry representatives to discuss emerging directions in materials science, advanced physical systems, functional materials engineering, and heritage technologies. The conference provided an interdisciplinary platform covering fundamental and applied research across electromagnetic and nonlinear systems, photonic and quantum platforms, heritage science and protective technologies, and advanced functional materials. Contributions addressed topics ranging from magnetic field engineering and nonlinear circuit dynamics to topological photonics, optomechanical systems, digital heritage frameworks, sustainable polymers, graphene-enabled surface technologies, and advanced materials interfaces. CRISTMas 2025 continued its mission of fostering dialogue between fundamental science and practical implementation, supporting the translation of advanced materials research into engineering solutions and societal applications. The proceedings reflect this interdisciplinary character and present peer-reviewed contributions that demonstrate both scientific rigor and applied relevance. List of Editorial Board, Scientific and Organising Committee are available in this PDF.

The integration of robotics and artificial intelligence (AI) into nanomedicine represents a significant advancement in developing targeted therapeutic and diagnostic platforms. This field focuses on engineering micro- and nanoscale agents, such as magnetic nanoparticles (MNPs), microbots, and nanobots, for tasks like targeted therapies, sensing, and manipulation at diseased sites. MNPs are typically composed of iron oxides and serve as foundational components due to their biocompatibility, tunable surface chemistry, and responsiveness to external magnetic fields. They are used in targeted drug delivery, magnetic hyperthermia for tumor ablation, and as contrast agents in magnetic resonance imaging (MRI) and magnetic particle imaging (MPI). Microbots and nanobots, which often incorporate MNPs for propulsion, can be actively guided using external magnetic fields to navigate complex biological environments, perform micromanipulation, and enable triggered drug release. The precise control of these magnetic agents relies on electromagnetic or permanent magnet-based guidance systems, which balance magnetic force strength, workspace volume, and clinical integration. Other classes like biohybrid microbots or DNA nanobots, utilize magnetic field independent mechanisms for molecular sensing and cargo delivery. AI and machine learning enhance these systems by optimizing material and bot design through in silico modeling, facilitating real-time navigation via medical imaging feedback, and enabling adaptive pathfinding. AI can also support swarm control and data analysis for diagnostic improvement. However, clinical translation faces challenges, including ensuring long-term biocompatibility and biodistribution, achieving scalable Good Manufacturing Practice (GMP) production, demonstrating therapeutic advantage in preclinical models, navigating evolving regulatory frameworks, and securing sufficient funding.

Design and development of dynamic electromagnetic system for actuation of magnetic endocapsule devices

Terahertz (THz) broadband absorbers with high efficiency and tunability are crucial for applications in electromagnetic shielding, sensing, stealth technology, and THz communication systems. In this work, an ultra-broadband, thermally tunable THz absorber with high fabrication tolerance is proposed based on the phase-change material vanadium dioxide (VO2). The absorber adopts a metal-dielectric-metal (MDM) configuration, consisting of a gold reflective layer, a SiO2 dielectric spacer, and a patterned VO2 top layer. When VO2 is in the metallic phase, the absorber achieves absorptance exceeding 90% over the frequency range of 3.1-10.0 THz, with a large fractional bandwidth of 105.34%. The broadband absorption mechanism is revealed through impedance matching analysis, multiple reflection interference theory, electric-field distribution analysis, and multipole decomposition. The results show that the absorption is primarily driven by electric dipole resonance, with contributions from toroidal and magnetic dipole resonances, which effectively confine electromagnetic energy and suppress reflection. Thermal modulation of the VO2 phase transition enables dynamic tunability of the absorption response, while parametric and structural-shape analyses confirm excellent fabrication tolerance. This work demonstrates that the proposed VO2-based metamaterial absorber provides a practical solution for advanced THz functional devices, combining high efficiency, broadband performance, and robust fabrication compatibility.

Although high-frequency electromagnetic methods, such as Radio Magnetotellurics (RMT) and Controlled-Source Radio Magnetotellurics (CSRMT), are highly effective for shallow-to-medium depth exploration, deploying traditional transmitter-receiver setups remains labor-intensive and significantly slows down large-scale surveys. To overcome these logistical bottlenecks, we developed a mobile Ultra-Audio Frequency Electromagnetic (UAEM) measurement system. While the hardware is designed with dual-mode capabilities supporting conventional controlled-source operations, this paper specifically focuses on its application in a Signals of Opportunity (SOOP) mode. By utilizing pre-existing, stable anthropogenic signals, including Amplitude Modulation (AM) broadcasts and naval very low frequency communications, the system effectively functions as a broadband RMT receiver. Technical evaluations demonstrate that the instrument operates across a 1 Hz to 1000 kHz bandwidth with a high sampling rate of 2.5 MHz. Furthermore, it achieves a dynamic range of 143 dB and maintains an apparent resistivity measurement accuracy of better than 3%. Thanks to its modular, vehicle-towed design, the UAEM system enables continuous, on-the-move data acquisition wherever ambient field sources are available. This approach eliminates the need for dedicated transmitter deployment, fundamentally reducing exploration costs and boosting overall survey efficiency.

Abstract The high energy consumption and severe coil heating issues of electromagnetic levitation systems constrain the engineering implementation of 600 km h −1 high-speed maglev transportation. To address this, a novel electromagnet structure which is permanent magnet electromagnetic hybrid levitation electromagnet is proposed. This paper analyzes the static and dynamic characteristics of the hybrid levitation electromagnet. First, the influence of permanent magnet dimensions on the static magnetic force characteristics of the hybrid levitation system is examined; Second, two solutions–applying reverse current and rotating the permanent magnet magnetic circuit–are proposed to address the hybrid levitation electromagnet’s magnet-rail contact issue, with their feasibility verified. Finally, based on the hybrid levitation system design, a single-point levitation control model is established to investigate the system’s dynamic behavior under track irregularity excitation. Findings reveal that the hybrid levitation system achieves significant energy savings and mitigates electromagnet heating. As the permanent magnet volume increases, magnetic force levels rise continuously, but electromagnetic controllability decreases accordingly. Based on the analysis results, the permanent magnet is installed at the center position of the magnetic yoke, with a height and thickness of 175 mm and 40 mm, respectively. Compared to conventional levitation electromagnets, the hybrid levitation system can reduce coil current and vertical acceleration, but it increases current fluctuation and gap fluctuation.

Ultra-high field MRI (≥ 7 T) offers unprecedented potential for mapping non-human primate (NHP) brain function. However, complex electromagnetic systems are required to meet the challenges of UHF imaging and the mechanical demands of awake NHP studies. To address these challenges, we developed a hybrid RF coil system optimized for whole-brain fMRI of macaques at 7 T. The hybrid coil system combines a 6-channel preamplifier-decoupled transceive dipole array with a 16-channel loop receive array, housed in a compact structure designed for awake imaging that maintains open visual fields. Key design features include compatibility with sphinx-position monkey chairs and head fixation systems required for awake experiments. Electromagnetic simulations guided dipole design to optimize uniform transmit performance and deep penetration. Phantom and in vivo experiments validated these predictions using anesthetized macaques and evaluated the system's readiness for awake imaging. The hybrid coil demonstrated uniform distribution with phase-shimmed transmission across the brain. It supported robust parallel imaging, enabling up to R = 3 × 2 acceleration factors for high-resolution acquisitions. The achieved whole-brain tSNR in fMRI is comparable to that of an existing 8-TX/24-RX coil designed for imaging anesthetized macaques. Critically, submillimeter (0.75 mm isotropic) resting-state fMRI revealed clear default-mode network connectivity, confirming the system's capability for high-quality functional imaging. By effectively addressing both the technical challenges of ultra-high field MRI and the mechanical constraints associated with visual stimulation in awake NHPs, this hybrid coil system provides a powerful tool for advancing our understanding of primate brain function.

Nanotechnology continues to advance rapidly, revealing previously unexplored directions in nanoscale communications. Biological and electromagnetic nanonetworks—established communication paradigms at the nanoscale—have shifted interest toward the middle and higher levels of the nanonetworking protocol stack. Motivated by the discovery of Cable Bacteria (CB) and their unique properties, we propose a theoretical model and framework for a new category of nanonetworks: bioelectrical nanonetworks (BioEN). This proposed framework combines the biocompatibility, sustainability and inherent nanodimensions of biological organisms with the networking performance of electromagnetic systems. Large-scale formations (e.g., 10,000 cells spanning nearly 2 cm), together with the electrical characteristics of CB, suggest the feasibility of guided electron-based transport that could complement diffusion-dominated nanonetworks, subject to resistive-capacitive (RC) constraints that remain to be quantified. Furthermore, we present a set of basic network architectures—such as star, ring, and tree—introducing a conceptual bio-multiplexer component, which utilizes CB to form a bioelectrical nanonetwork and illustrate core functionalities primarily at the network layer. Within this theoretical framework, BioEN is positioned as a potential enabler for diverse scientific, environmental, and technological applications, including health and ecosystem biosensing and bioremediation-oriented bioengineering. This work is conceptual and does not experimentally validate a deployed nanonetwork; instead, it establishes the design principles, abstractions, and architectural foundations intended to guide future implementation and experimental verification of bioelectrical nanonetworks.

This study introduces the Doha Time–Dimension Phase Resonance framework, in which time and dimension are interpreted as emergent properties of phase-synchronized interactions across biological, environmental, and electromagnetic systems. Rather than treating dimension as a static spatial extension, the framework conceptualizes it as a phase-dependent structure arising from temporal resonance (Φk). Within this model, time is represented as a multilayered oscillatory architecture composed of four interwoven domains: planetary electromagnetic rhythms, intrinsic biotemporal cycles, artificial synchronization systems, and quantum–informational fluctuation fields. Dynamic phase coupling among these domains is associated with physiological coherence, cognitive stability, and the continuity of temporal experience. Dimensional modulation is interpreted as a result of systemic phase reorganization, while recurrent energetic cycles—condensation, discharge, recovery, and recharge—are introduced as candidate mechanisms underlying metabolic and memory-related processes. Disruptions in cross-domain synchrony are associated with variations in physiological regulation and perceptual alignment. The framework is formulated as a conceptual and testable systems-level model, with potential empirical grounding in measurable indicators such as EEG phase synchrony, heart rate variability, mitochondrial rhythmic activity, and geophysical resonance patterns. Rather than replacing established theories, this work provides a complementary systems-level perspective on temporal organization in biological systems through phase-based dynamics.

Three-phase electromagnetic induction motors are extensively used in industrial applications because of their robustness, simple design, ease of manufacturing, and low maintenance requirements. Consequently, they power more than 90% of industrial mechanical systems. Recent research increasingly applies artificial intelligence techniques to improve motor design, efficiency, and performance analysis. A key focus of these efforts is reducing energy losses, including copper, mechanical, and electromagnetic core losses. This study examines electromagnetic iron losses in a three-phase power transformer, which serves as a representative electromagnetic induction system. The transformer is selected because its equivalent circuit closely resembles that of the induction motor. To isolate core-loss mechanisms, copper losses in the windings are excluded from the analysis. Although transformers transfer electrical energy between circuits while induction motors convert electrical energy into mechanical power, both operate on the same electromagnetic induction principles. As a result, their core losses arise from similar physical effects, primarily hysteresis and eddy currents. The investigation employs ANSYS Finite Element Analysis software to develop an accurate computational model of the transformer. Simulation results are validated through experimental data obtained from a transformer meeting the specifications at Østfold University College in Norway. The study compares the efficiency and iron losses of an amorphous-core transformer made of Metglas-2605HB1M operating at 50 Hz with those of a conventional M19 silicon steel core transformer across different frequencies. In addition, a newly designed high-frequency transformer is presented. The results show that amorphous-core transformers achieve lower core losses and higher efficiency than M19 silicon-steel core transformers, supporting cleaner, more energy-efficient electromagnetic induction systems with reduced CO 2 emissions.

Retrospective cohort study. To evaluate the clinical efficacy and advantages of integrated optical and electromagnetic navigation-guided biportal endoscopic unilateral laminotomy for bilateral decompression (navigation-guided BE-ULBD, Ng-BE-ULBD) in patients with lumbar spinal stenosis (LSS). The use of surgical navigation improves procedural precision and contributes to reduced operative time and fluoroscopy exposure. However, currently available navigation systems have notable limitations: optical navigation is influenced by lineof- sight obstruction, while electromagnetic navigation is easily affected by interference from metallic instruments. A retrospective analysis was performed on patients who underwent BE-ULBD for LSS at Beijing Chaoyang Hospital between August 2023 and June 2025. Patients treated using an integrated optical and electromagnetic surgical navigation system were categorized into the Ng-BE-ULBD group (n=84), whereas those treated under conventional C-arm fluoroscopy guidance were included in the Carm- guided BE-ULBD (C-BE-ULBD) group. Baseline demographic and clinical characteristics, operative time, number of fluoroscopy shots, clinical outcomes, and postoperative complications were recorded and compared between the two groups. The total operative time for both single- and two-level decompressions was significantly shorter in the Ng-BE-ULBD group (81.40 minutes and 144.56 minutes, respectively) than in the C-BE-ULBD group (88.79 minutes and 159.53 minutes, respectively; p <0.05), with the most substantial difference observed in catheter placement time. The total number of fluoroscopy shots was also significantly lower in the Ng-BE-ULBD group (p <0.05). Postoperatively, both groups exhibited significant improvement in pain relief, functional recovery, and patient satisfaction. However, no significant differences were identified between the two groups regarding decompression time, complication rates (Ng-BE-ULBD: 3.6% vs. C-BE-ULBD: 7.3%), postoperative pain or functional improvement, or length of hospital stay (p >0.05). The integrated optical and electromagnetic surgical navigation system effectively reduces radiation exposure and shortens operative time, thereby improving surgical efficiency and safety. These findings demonstrate strong clinical potential for this technology in minimally invasive spine surgery.