Conversion Of Electromagnetic Energy Research Articles

Correction to “The Proof of Concept of Uninterrupted Push‐Pull Electromagnetic Propulsion and Energy Conversion Systems for Drones and Planet Landers”

Correction to “The Proof of Concept of Uninterrupted Push‐Pull Electromagnetic Propulsion and Energy Conversion Systems for Drones and Planet Landers”

Effect of entropy evolution on electromagnetic response mechanism of carbon-coated medium- and high-entropy oxides

Metal oxides have attracted much attention due to their potential in electromagnetic wave absorption. However, the inherent energy dissipation capabilities of low-entropy metal oxides pose challenges in designing materials with optimal entropy levels. The regulation of entropy structure is anticipated to facilitate the development of novel electromagnetic functional materials featuring abundant active sites, adjustable specific surface area, stable crystal structure, unique geometric compatibility, and distinctive electronic structure. This study compared the electromagnetic loss performance of low, medium, and high entropy metal oxides in carbon matrices. As entropy increases, the number of phases expands, leading to enhanced interface polarization losses and improved impedance matching. However, further increases in entropy result in performance decline due to lattice distortions and mismatches in dielectric constant and magnetic permeability. Experimental data and theoretical analysis reveal that performance enhancement in medium-to high-entropy metal oxides is attributed to their unique morphology and the synergistic effects of multiple metal components, which enhance interfacial and defect polarization mechanisms. Heterogeneous interfaces and lattice defects provide additional polarization sites, aiding in the conversion of electromagnetic energy into heat. The presence of intermediate phases effectively absorbs and dissipates electromagnetic waves, thereby enhancing the overall absorption capability.

Bidirectional, Multilayer MXene/Polyimide Aerogels for Ultra-Broadband Microwave Absorption.

To obtain high-performance electromagnetic microwave (EM) absorption materials with broad effective absorption bandwidth (EAB) and reduced thickness, designing structures has proved to be a promising way. Herein, ultra-broadband multilayer bidirectional MXene/polyimide EM absorption aerogels containing multi-structures on scales ranging from the micro- to the macroscale are produced with the aid of electric and temperature fields. On the microscale, under the action of electric force and temperature gradient, the ordered structures made of aligned Ti3C2Tx MXene nanosheets and the microscale layered aerogel walls enable the bidirectional aerogel to achieve a wide EAB of 8.58GHz at a thickness of 2.1mm. This is ascribed to the numerous aligned nanosheets and layered aerogel walls perpendicular to the incident EMs, facilitating the conversion of electromagnetic energy into electrical energy. Furthermore, on the macroscale, the multilayer bidirectional aerogel with non-gradient structures effectively resolves the conflict between impedance matching and energy loss, resulting in an ultrawide EAB of 9.41GHz at a thickness of 3mm. This innovative design of electric-field-assisted multilayer bidirectional aerogels with multiscale structural coupling may provide feasible and effective pathways for the development of advanced EM absorption materials.

Piezoelectric-electromagnetic collaborative energy extraction circuit for wearable vibration energy harvester

A piezoelectric-electromagnetic collaborative energy extraction circuit (PEC-EC) is presented in this paper to extract low-frequency vibration energy from arm swinging for wearable devices. This circuit simultaneously harvests energy from both the piezoelectric transducer (PZT) and electromagnetic coil generator (ECG). When the piezoelectric output voltage reaches its peak, the peak detection circuit becomes conductive, and the energy of the piezoelectric material is extracted at this moment. At the same time, the PEC-EC circuit can also harvest electromagnetic energy. Especially, even at low electromagnetic voltage input, the electromagnetic voltage can be extracted through the designed switch. The experimental results show that the circuit starts up only when the input voltage reaches 0.5V. The electromagnetic energy conversion efficiency can reach 53 %, and the piezoelectric energy conversion efficiency can reach 56 %. The effectiveness of collaborative extraction was also verified through experimental validation.

An LCC-CS bilateral matching network for high efficiency energy conversion in high-frequency piezoelectric rotary ultrasonic machining system

The processing efficiency and machining quality of piezoelectric rotary ultrasonic machining (PRUM) system are closely related to its electromagnetic energy conversion units and electroacoustic energy conversion units. Generally, the high efficiency and high-power capacity of PRUM systems are limited by several energy conversion devices including the capacitive piezoelectric transducer (PT) load, loosely coupled rotating transformer (RT), and non-soft switching inverter. This article improves the overall performance of high-frequency PRUM system by bilateral matching network. On the rotating side, the compared results of five different static matching schemes show that the CS matching scheme ensures stable and efficient vibration of capacitive PTs even under incomplete matching. On the stationary side, a dynamic LCC matching scheme is adopted to keep the output impedance angle of H-bridge inverter in the weak inductive state. Finally, the proposed high-order matching network in this article makes the efficiency of high-frequency PRUM system over 90 % steadily.

Flower-like Cu9S5 and magnetic NiCo@C particles synergize to build three-dimensional conductive networks for efficient electromagnetic wave absorption

To increase the use of sulfides in electromagnetic wave absorption, researchers are continuously developing thin semiconductor sulfide absorbers with significant absorption capacity and wide bandwidth. In this study, we synthesized NiCo@C/Cu9S5 materials with the dual loss mechanism (dielectric and magnetic losses) by evenly loading magnetic NiCo@C particles on flower-like Cu9S5 matrixes utilizing the magnetic derivatization technique for metal-organic frameworks (MOFs). The three-dimensional flower-like structures of the composites, intrinsic properties of the materials, and the resulting three-dimensional conductive network endow the material with multiple scattering and reflection, conduction loss, resonance, and eddy current properties. The synergistic effect of these loss pathways leads to the outstanding electromagnetic wave (EMW) absorption performance of the materials. The results show that the minimum reflection loss (RLmin) of NiCo@C/Cu9S5 can reach −52.83 dB when the matching thickness is 2.09 mm. Meanwhile, the maximum effective absorption band (EAB) is 5.1 GHz (12.3–17.4 GHz) at a matching thickness of 1.69 mm. Furthermore, the radar cross section (RCS) of the absorbers has been calculated by CST Studio Suite, demonstrating the ability of the absorbent coating to lower the RCS at different angles efficiently. These discoveries provide new insights for high-performance sulfide electromagnetic wave absorbers and contribute to electromagnetic wave energy storage and conversion studies.

Multidimensional hollow SiO2/C nanofibers modified by magnetic nanocrystals for electromagnetic energy conversion and lithium battery storage

Multidimensional hollow SiO2/C nanofibers modified by magnetic nanocrystals for electromagnetic energy conversion and lithium battery storage

Photobiomodulation on isolated mitochondria at 810 nm: first results on the efficiency of the energy conversion process

In this paper the photobiomodulation on isolated mitochondria of bovine liver is studied as a thermodynamic process of conversion of energy. This analysis is conducted by considering a particular set-up for the photobiomodulation experiments of interest. It allows, in particular, the computation of the electromagnetic field and the related energetic quantities in the stimulated organelles. The measurements of the excess of biochemical power density produced by the illuminated mitochondria are performed at regular time intervals after the experiments. The calculations and the measurements finally allow us to obtain the first results on the efficiency of the process of conversion of electromagnetic energy into excess of biochemical energy released by the isolated organelles.

Study on fused deposition modeling forming and properties of PP/RGO composite materials

Lightweight and efficient absorbing materials are considered a viable solution for mitigating electromagnetic wave pollution. Graphene, with its unique multi-layer structure, facilitates multiple reflections and scattering of electromagnetic waves, thereby enabling the conversion of electromagnetic wave energy into other forms. In this study, composite materials consisting of PP and RGO were prepared using FDM. The results revealed that PP-based composites exhibited favorable mechanical properties, with a tensile strength of 24.7 MPa and elongation at break of 28.8 %. For instance, at 5 % RGO content and a thickness of 2.1 mm, the composite material exhibited an absorption of −38.09 dB and 4 GHz. Notably, by varying the thickness within the range of 1–4 mm, the absorption bandwidth could cover a frequency range of 6–18 GHz. The combination of absorption and mechanical properties in these composite materials holds significant potential for the development of efficient and broadband absorption devices.

Flexible Ultrasonic‐Induced Wireless Energy Conversion Technology in Implantable Biomedicine

AbstractNumerous associated challenges arise with the advancement and continuous improvement of implantable medical devices, such as the frequent requirement for battery replacement. The flexible ultrasonic‐induced wireless energy conversion (UWEC) technology has garnered significant interest due to its superior energy transmission efficiency, safety, and biocompatibility compared to traditional electromagnetic wireless energy conversion technology. This paper provides a comprehensive review of the recent advancements in two types of flexible UWEC technologies, triboelectric nanogenerators, and piezoelectret nanogenerators, with a focus on their applications in implantable medical treatments. First, the energy conversion principles and general materials of flexible UWEC are presented. Then, the research and application of flexible UWEC devices are introduced in detail based on their medical functions. At the end of this review, perspectives and opportunities are discussed.

Bead-like Co/C@MoS2Composites connected by Multi-Walled carbon nanotubes for high-efficiency electromagnetic wave absorption

This study presents a novel approach to synthesize a composite material composed of bead-like Co/C nanoparticles anchored on MWCNTs, encapsulated by MoS2 nanosheets through a combination of carbonization and hydrothermal treatment using ZIF-67 as the precursor. The resulting composite demonstrates exceptional electromagnetic wave (EMW) absorption performance, with a minimum reflection loss (RL) of −63 dB at a thickness of 2.44 mm and an effective absorption bandwidth (EAB) of 7.2 GHz when RL is below 10 dB together with an expanded EAB of 12.3 GHz (d = 5 mm).The superior absorption capabilities arise from a well-thought-out design of material composition and structure. The synergy of Co/C and MWCNTs enhances ferromagnetic resonance, conductivity, and polarization loss, while sulfur vacancies in MoS2 act as polarization centers, facilitating dipole polarization and efficient conversion of electromagnetic wave energy. The core–shell structure and heterogeneous interfaces introduce various energy loss mechanisms, including multiple polarizations, scattering effects, and dielectric loss. This work introduces a facile method for synthesizing a composite material with outstanding EMW absorption performance. The synergistic combination of unique material components and the carefully engineered structure make this composite a promising candidate for advanced applications in electromagnetic wave absorption technology.

Multi-interfacial bridging engineering of flexible MXene film for efficient electromagnetic shielding and energy conversion

Accompanied by the progressive development of electronic equipment, excellent electromagnetic interference (EMI) shielding materials display a satisfying prospect in protecting electronic devices against electromagnetic pollution/radiation, while integrating energy conversion. Heretofore, it remains a conundrum to availably construct thin films with multi-interfacial bridging engineering as multifunctional shielding devices. To effectively achieve electromagnetic wave attenuation and integrate energy conversion, a co-mixed vacuum-assisted filtration strategy is designed to synthesize Au@MXene/cellulose nanocrystal/dodecylbenzenesulfonic acid-doped polyaniline (AMCP) films. Profited from the interfacial engineering, the total EMI shielding effectiveness (SE) can be increased by 27 % with the highest value of 67.9 dB. MXene with localized surface plasmon resonance characteristics gives the composite films good energy conversion performance, that is, the composite film can be rapidly heated up to 100 °C under the irradiation of an infrared lamp, and its surface temperature remains stable after continuous irradiation. Additionally, the infrared emissivity is as low as 0.173 within the 8–14 μm, which is necessary to adapt various application scenarios. Therefore, it is reliable that the AMCP films constructed by multicomponent offer a facile strategy for MXene-based EMI shielding devices with integration characteristics.

Heterodimensional hybrids assembled with multiple-dimensional copper selenide hollow microspheres and graphene oxide nanosheets for electromagnetic energy conversion and electrochemical energy storage

Heterodimensional hybrids assembled with multiple-dimensional copper selenide hollow microspheres and graphene oxide nanosheets for electromagnetic energy conversion and electrochemical energy storage

Design and analysis of an electromagnetic energy conversion device

In this study,we introduces an innovative device designed for wave-heat-electricity conversion, incorporating a classical split-ring resonator (SRR) and a Bi2Te3 semiconductor strip. This configuration is adept at absorbing electromagnetic energy, transforming it into thermal energy, and facilitating an electrical response. The paper delves into the detailed physical modeling and operational principles of the device. We begin by employing an equivalent circuit model to analyze the SRR's transmission characteristics and its temperature response under specific conditions. The investigation further extends to examining how structural dimensions and material properties affect the development of a local hotspot, leading to the refinement of the SRR resonant unit. We then integrate a Bi2Te3 semiconductor strip beneath this hotspot, enhancing the device's conversion capabilities. Our findings indicate an absorption efficiency of 0.085 at 2.45 GHz, a remarkable thermal conversion efficiency of 172.8 °C/W, and an electrical conversion efficiency of 0.195 mV/°C, all measured at an input power of 7 W. This research not only demonstrates the efficacy of the proposed device in wave-heat-electricity conversion but also provides a comprehensive reference for future advancements in this field.

Multifunctional WSe2/Co3C composite for efficient electromagnetic absorption, EMI shielding, and energy conversion

Multifunctional WSe2/Co3C composite for efficient electromagnetic absorption, EMI shielding, and energy conversion

Optimum Design of a Reusable Spacecraft Launch System Using Electromagnetic Energy: An Artificial Intelligence GSO Algorithm

Due to its advantages of high acceleration, reusability, environmental protection, safety, energy conservation, and efficiency, electromagnetic energy has been considered as an inevitable choicefor future space launch technology. This paper proposes a novel three-level orbital launch approach based on a combination of a traditional two-level orbital launch method and an electromagnetic boost (EMB), in whichthe traditional two-level orbital launch consists of a turbine-basedcombined cycle (TBCC) and a reusable rocket (RR). Firstly, a mathematical model of a multi-stage coil electromagnetic boost system is established to develop the proposed three-level EMB-TBCC-RR orbital launch approach, achieving a horizontal take-off–horizontal landing (HTHL) reusable launch. In order to optimize the fuel quality of the energy system, an artificial intelligence algorithmparameters-sensitivity-basedadaptive quantum-inspiredglowworm swarm optimization (AQGSO)is proposed to improve the performance of the electromagnetic boosting system. Simulation results show that the proposed AQGSO improves the global optimization precision and convergence speed. By using the proposed EMB-TBCC-RR orbital launch system and the optimization approach, the required fuel weight was reduced by about 13 tons for the same launch mission, and the energy efficiency and reusability of the spacecraft was greatly improved. The spacecraft can be launched with more cargo capacity and increased payload. The proposed novel three-level orbital launch approach can help engineers to design and optimize the orbital launch system in the field of electromagnetic energy conversion and management.

Research on electromagnetic energy absorption and conversion device with four-ring multi-resistance structure

A device for electromagnetic energy absorption and conversion was investigated as an electromagnetic energy harvester, which is based on a four-ring multi-resistance unit. The device can convert microwave energy to thermal energy and then to electrical energy through the Bi2Te3 thermoelectric material adhered to the load resistance. The energy harvesting efficiency, power loss distribution, and current density distribution of the harvester were analyzed. In addition, the energy harvesting efficiency of the unit under different incident angles and polarization angles was studied, and the effect of incident power on the temperature and energy conversion efficiency of the unit was analyzed. The simulation results showed that the energy harvesting efficiency of the harvester reaches 99.5% at 5.8 GHz. Each unit in the harvester can generate an output voltage of 171.8 mV under 7 W incident wave power, and the maximum output power is 9.71 mW. To verify the effectiveness of this method, a 5 × 5 unit array model was fabricated and measured, and the measurement results were consistent with the simulation results.

Resonant Scattering of Gravitational Waves with Electromagnetic Waves

A certain class of exact solutions of Einstein Maxwell spacetime in general relativity is discussed to demonstrate that at the level of theory, when certain parametric resonance condition is met, the interaction of electromagnetic field with a gravitational wave will display certain Lyapunov instability and lead to exponential amplification of a gravitational wave train described by certain Newman–Penrose component of the Weyl curvature. In some way akin to a free electron laser in electromagnetic theory, by the conversion of electromagnetic energy into gravitational energy in a coherent way, the feasibility of generating a pulsed-laser-like intense beam of gravitational wave is displayed.

Wave-heat-electricity conversion: Design and analysis of an electromagnetic energy conversion device

An innovative electromagnetic energy harvester was developed using a compact four-ring single-resistor unit cell. To achieve efficient conversion of electromagnetic waves into electricity, we integrated the high-performance Bi2Te3 thermoelectric material onto the load resistor. Remarkably, this unit cell exhibits exceptional energy harvesting capabilities at a frequency of 5.8 GHz while maintaining polarization insensitivity. Through comprehensive analysis, we evaluated the energy harvesting efficiencies, power loss distribution, and current density distribution. Additionally, we investigated the impact of incident power on the unit cell's temperature and energy conversion efficiencies. To enhance energy concentration on the load, we ingeniously designed an “L-shaped” metal through-hole structure within the four-ring single-resistor unit cell. Our results demonstrate that the four-ring single-resistor unit cell achieves an impressive harvesting efficiency of 94.5% at 5.8 GHz, with a thermal conversion efficiency of 43.3 °C/W, an electrical conversion efficiency of 0.23 mV/°C, and an electrical response rate of 9.4 mV/W. Notably, when subjected to a power input of 7 W, the unit cell produces an output voltage of 65.9 mV, and its theoretical maximum output power reaches 180 mW.

Electromagnetic Conversion into Kinetic and Thermal Energies.

The conversion of electromagnetic energy into magnetohydrodynamic energy occurs when the electric conductivity changes from negligible to finite values. This process is relevant during the epoch of reheating in the early universe at the end of inflation and before the emergence of the radiation-dominated era. We find that the conversion into kinetic and thermal energies is primarily the result of electric energy dissipation, while magnetic energy only plays a secondary role in this process. This means that since electric energy dominates over magnetic energy during inflation and reheating, significant amounts of electric energy can be converted into magnetohydrodynamic energy when conductivity emerges before the relevant length scales become stable.