Analysis Of Electric Field Distribution Research Articles

Enhanced electromagnetic wave absorption in ultrathin cement-based composites with integrated multi-dimensional carbon materials

The challenges posed by electromagnetic waves (EMW) cause significant interference in electronic device operation, jeopardizing information security and disturbing normal biological functions, which necessitate attention. Multi-scale carbon/cement-based composites were developed for EMW absorption by integrating multi-dimensional carbon materials, including carbon nanotubes (1D), graphene (2D), and modified carbon microspheres (3D). These composites demonstrate exceptional EMW absorption capabilities, with a minimum reflection loss (RLmin) of −44.32 dB and an effective absorption bandwidth (EAB) of 3.644 GHz at X band, merely having a thickness of 1.90 mm. Furthermore, the superior EMW absorption properties of these composites are confirmed through radar cross-section (RCS) simulation and electric field distribution analysis. A small house is constructed of designed three-layer multi-scale carbon/cement-based composites in which the actual EMW reflection losses are less than –10 dB within the whole test frequency range, and these composites can effectively obstruct 5 G mobile phone signals. Therefore, multi-scale carbon/cement-based composites could be promising candidates for effectively solving the increasingly serious problem of electromagnetic radiation pollution.

Transmission/reflection mode switchable ultra-broadband terahertz vanadium dioxide (VO2) metasurface filter for electromagnetic shielding application

In this paper, we present an ultra-broadband terahertz (THz) vanadium dioxides (VO2) metasurface (MS) filter with switchable transmission/reflection modes for electromagnetic (EM) shielding application. The MS filter is composed of a three-layer periodic composite structure, consisting of two VO2/metallic hybrid layers and a metal mesh layer, which are separated by two benzocyclobutene (BCB) dielectric layers. The transmission property of the proposed MS filter is illustrated by the numerical simulation based on the finite element method (FEM) and equivalent circuit model (ECM). When VO2 is in insulating state, the designed composite structure acts as a filter with ultra-broadband bandpass response (BPR), exhibiting that the transmission coefficient exceeds 90 % from 1.07 THz to 3.78 THz, with a relative bandwidth of 112 %. However, owing to thermal excitation, the VO2 converts from an insulating to a metallic state, the composite structure can be functioned as a filter with ultra-broadband bandstop response (BSR) with a transmission coefficient less than 6 % spanning the range of 0.1 to 4.5 THz. In addition, the physical mechanism of the designed MS filter is investigated utilizing impedance matching theory and electric field distribution analysis. Furthermore, the MS filter has good polarization insensitivity and angular stability. Finally, we quantify the shielding effectiveness (SE) in two states and evaluate the impact structural parameters of the unit-cell, resulting in a SE of more than 25 dB in reflection mode across the entire operating frequency range. Our proposed MS filter with its exquisite performance has the potential to be widely applied in EM shielding.

Optimizing tumor treating fields for blood cancer therapy: Analysis of electric field distribution and dose density

Optimizing tumor treating fields for blood cancer therapy: Analysis of electric field distribution and dose density

Symmetric left-handed split ring resonator metamaterial design for terahertz frequency applications

This work focused on the novel symmetrical left-handed split ring resonator metamaterial for terahertz frequency applications. A compact substrate material known as Silicon with a dimension of 5 µm was adopted in this research investigation. Moreover, several parameter studies were investigated, such as clockwise rotation, array and layer structure designs, larger-scale metamaterials, novel design structure comparisons and electric field distribution analysis. Meanwhile, two types of square-shaped metamaterial designs were proposed in this work. The proposed designs exhibit double and single resonance frequencies respectively, likely at 3.32 and 9.24 THz with magnitude values of − 16.43 and − 17.33 for the first design, while the second design exhibits a response at 3.03 THz with a magnitude value of − 19.90. Moreover, the verification of these results by adopting High-frequency Structure Simulator software indicates only slight discrepancies which are less than 5%. Furthermore, the initial response of the proposed designs was successfully altered by simply rotating the design clockwise or even increasing the dimension of the design. For instance, the first resonance frequency is shifted to the lower band when the first proposed design was rotated 90°. On the other hand, by increasing the size of the metamaterial, more than nine resonance frequencies were gained in each symmetric design. Furthermore, the symmetric metamaterial with a similar width and length of 10 µm dimension was adopted for both design structures to construct an equivalent circuit model by utilising Advanced Design System software. Finally, both unit cell designs were utilised to explore the absorption performances which exhibit four and five peak points. Overall, the altering behaviour by changing physical properties and compact design with acceptable responses become one of the novelties of this research investigation. In a nutshell, the proposed designs can be utilised in terahertz frequency which gives optimistic or advantageous feedback and is relatively suitable for the adopted frequency range.

Electric Fields at the Lipid Membrane Interface.

This review presents a comprehensive analysis of electric field distribution at the water-lipid membrane interface in the context of its relationship to various biochemical problems. The main attention is paid to the methodological aspects of bioelectrochemical techniques and quantitative analysis of electrical phenomena caused by the ionization and hydration of the membrane-water interface associated with the phase state of lipids. One of the objectives is to show the unique possibility of controlling changes in the structure of the lipid bilayer initiated by various membrane-active agents that results in electrostatic phenomena at the surface of lipid models of biomembranes-liposomes, planar lipid bilayer membranes (BLMs) and monolayers. A set of complicated experimental facts revealed in different years is analyzed here in order of increasing complexity: from the adsorption of biologically significant inorganic ions and phase rearrangements in the presence of multivalent cations to the adsorption and incorporation of pharmacologically significant compounds into the lipid bilayer, and formation of the layers of macromolecules of different types.

Finite element analysis of electric field distribution during direct current stimulation of the spinal cord: Implications for device design.

Spinal cord injury (SCI) arises from damage to the spinal cord, often caused by trauma or disease. The resulting sensorimotor dysfunction is variable and dependent on the extent of the injury. Despite years of research, curative options for SCI remain limited. However, recent advancements in electric field stimulated axonal regrowth have shown promise for neuronal regeneration. One roadblock in the development of therapeutic treatments based on this is a lack of understanding of the exogenous electric field distribution in the injured tissue, and in particular, how this is influenced by electrode geometry and placement. To better understand this electric field, and provide a means by which it can be optimized, we have developed a finite element model of such spinal cord treatment. We investigate the impact of variations in electrode geometry, spinal cord size, and applied current magnitude as well as looking at several injury models in relation to clinically observed outcomes. Through this, we show that electrode shape has little effect on the induced electric field, that the placement of these electrodes has a noticeable influence on the field distribution, and that the magnitude of this field is governed by both the applied current and the spinal cord morphology. We also show that the injury modality influences the induced field distribution and that a stronger understanding of the injury will help decide treatment parameters. This work provides guidance in the design of electrodes for future clinical application in direct current electric field stimulation for axonal regeneration.

Phase volume fraction measurement of vertical oil–water-gas flow using integrated optical-electrical coaxial cross-modal probe sensor

Measuring phase volume fraction is an essential part of petroleum exploration and development. According to the problems that the common sensors are unable to obtain the phase volume fraction of oil–water-gas flow, an integrated optical-electrical coaxial cross-modal probe sensor (IOECCMPS) is designed, and a phase volume fraction system based on IOECCMPS is developed for different oil–water-gas flow. Specifically, the electrical and optical mathematical models of the IOECCMPS were established, and theoretical analysis of electric field distribution and ray tracing results. We also analyzed the sensitivity distribution of the electrical measurement module (EMM). Based on the above results, the effects of structural parameters on its performance are discussed, including the electrode length, electrode thickness, the angle of the monitoring tip, and insulating tube structure. In addition, we also studied the response characteristics of the IOECCMPS in oil–water-gas flow. Furthermore, the IOECCMPS circuit was designed and experimented with on the oil–water-gas flow measurement platform. Experimental results show: the developed IOECCMPS can realize multi-phase measurement under oil–water-gas flow such as liquid flow rate range (0.42–2.92 m3/h), liquid water volume fraction range (50–90%), gas flow rate range (0.21–1.67 m3/h), etc., and the measurement error is within 5%. In the research work of this paper, the developed IOECCMPS can simultaneously accomplish the accurate measurement of phase volume fraction of oil–water-gas flow, which provides a reference for the development of oil production monitoring technology.

Design of a High-Performance Titanium Nitride Metastructure-Based Solar Absorber Using Quantum Computing-Assisted Optimization.

Metastructures of titanium nitride (TiN), a plasmonic refractory material, can potentially achieve high solar absorptance while operating at elevated temperatures, but the design has been driven by expert intuition. Here, we design a high-performance solar absorber based on TiN metastructures using quantum computing-assisted optimization. The optimization scheme includes machine learning, quantum annealing, and optical simulation in an iterative cycle. It designs an optimal structure with solar absorptance > 95% within 40 h, much faster than an exhaustive search. Analysis of electric field distributions demonstrates that combined effects of Fabry-Perot interferences and surface plasmonic resonances contribute to the broadband high absorption efficiency of the optimally designed metastructure. The designed absorber may exhibit great potential for solar energy harvesting applications, and the optimization scheme can be applied to the design of other complex functional materials.

Simulation Results and Analysis of Electric Field Distribution in Myocardial Tissue under Circular Electrode Electric Pulse Ablation

As a new energy source for atrial fibrillation ablation, electric pulse ablation has higher tissue selectivity and biosafety, so it has a great application prospect. At present, there is very limited research on multi-electrode simulated ablation of histological electrical pulse. In this study, a circular multi-electrode ablation model of pulmonary vein will be built on COMSOL5.5 platform for simulation research. The results show that when the voltage amplitude reaches about 900 V, it can make some positions achieve transmural ablation, and the depth of continuous ablation area formed can reach 3 mm when the voltage amplitude reaches 1 200 V. When the distance between catheter electrode and myocardial tissue is increased to 2 mm, a voltage of at least 2 000 V is required to make the depth of continuous ablation area reach 3 mm. Through the simulation of electric pulse ablation with ring electrode, the research results of this project can provide reference for the voltage selection in the clinical application of electric pulse ablation.

Single material with multiple interfaces: A key one dimensional barium titanate filler for enhancing energy density in polymer nanocomposite

The increasing demand of energy and its storage devices in consumer electronics requires high energy density capacitors. In this context, we proposed a filler of single material with multiple interfaces to enhance the energy density in polymer nanocomposite film. The core-shell polydopamine (PDA) coated BaTiO3 (BT) incorporated in 1D BT architecture filler was prepared by the electrospinning process. In order to investigate the effect of the interfaces, the poly(vinylidene-chlorotrifluoroethylene) (P(VDF-CTFE)) nanocomposite films of a fixed filler (BT, PDA coated BT and 1D core-shell BT) concentration were prepared. The introduction of a ferroelectric filler induces an electroactive phase in P(VDF-CTFE), leading to dielectric constant enhancement by 135% in nanocomposite film. This enhancement in dielectric constant is due to the increased polarizability of nanocomposite film, which was verified by the finite element analysis of electric field distribution. The ferroelectric (polarization vs electric field) loop measurement indicates that the multi-interfaced ferroelectric filler based nanocomposite film exhibits increased maximum polarization of 14.3 μC/cm2, breakdown strength of 5000 kV/cm and improved energy density of 9.9 J/cm3. It implying that an enormous increment (371%) of energy storage as compared to commercial biaxially orientated polypropylene (2.1 J/cm3).

Tunable ultrawideband perfect absorber based on vanadium dioxide

An ultrawideband metamaterial perfect absorber based on vanadium dioxide is proposed. It achieves >95 % absorption of vertically incident electromagnetic waves in the range of 3.50 to 10 THz. The absorption intensity can be dynamically adjusted in the range of 0.2% to 99.98% by varying the conductivity of VO2. The mechanism of ultrawideband perfect absorption is interpreted using electric field distribution analysis and impedance-matching theory. The absorption rate related to the structural parameters of the absorber is investigated by numerical simulation. Finally, its polarization angle-insensitive and incidence angle-insensitive properties are demonstrated. This proposed absorber has potential applications in optical switching, electromagnetic stealth, and sensing applications.

Ultramicro-sensing of terahertz metamaterials implemented by using sample traps

A metamaterial sensor implemented by using sample traps based on terahertz electromagnetically-induced-transparency-like (EIT-like) effect is proposed. The basic unit structure of the sensor is composed of a metal wire and a pair of split ring resonators (SRRs), which are coupled to produce EIT-like effect. The full width at half maximum of transparency peak is 178 GHz obtained at 1.067 THz, and the maximum transmittance of the transparency peak is 89.71%. The sensing characteristics of the structure are studied, and the sensitivity per unit volume is <inline-formula><tex-math id="M3">\begin{document}$178\;{\rm{G}}{\rm{H}}{\rm{z}}/({\rm{R}}{\rm{I}}{\rm{U}}{\cdot} {{\rm{m}}{\rm{m}}}^{3})$\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="12-20230080_M3.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="12-20230080_M3.png"/></alternatives></inline-formula>. The analysis of electric field distribution at the resonant frequency point of the metamaterial indicates that the electric field at the gap of the SRRs on both sides is strongest. Sample traps are constructed at the gap where the electric field is strongest. The photoresist is filled into the sample traps as the object to be measured, and 50 GHz frequency offset is successfully measured, verifying that the sample trap structure can be applied to sensing. With samples placed in the sample traps, the sample volume is reduced to the ultra-micro level, and the sensitivity per unit volume is increased to <inline-formula><tex-math id="M4">\begin{document}$5538\;{\rm{G}}{\rm{H}}{\rm{z}}/({\rm{R}}{\rm{I}}{\rm{U}}{\cdot} {{\rm{m}}{\rm{m}}}^{3})$\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="12-20230080_M4.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="12-20230080_M4.png"/></alternatives></inline-formula>, which is 31 times higher than original one. The successful identification of water, human skin and rat skin samples show that the metamaterial sensor implemented by using sample traps has potential applications in the field of ultra-micro detection.

A highly efficient deca-band metasurface absorber for diverse microwave applications

We propose a highly efficient, deca-band, and single-layered metasurface absorber (MA) based on the idea of split-ring resonators (SRRs). The unit cell of the proposed MA is a combination of 2 × 2 symmetrically arranged meta-structured designs, each comprising long and short L-shaped SRRs, two concentric semi-circular rings, and two T-shaped conducting strips. The absorption phenomenon of the proposed structure is successfully demonstrated using the standing wave resonance theory (SWRT), detailed current distribution, and the electric field distribution analysis. The thickness of the proposed MA unit cell is 0.96 mm having 1/56, 1/41, 1/35, 1/21, 1/20, 1/18, 1/17, 1/13, and 1/12 respective free-space wavelengths and has compact unit cell dimensions of 0.018λo×0.018λo, where λo corresponds to the lowest absorption frequency. The proposed structure offers absorption peaks of more than 90% at 10 distinct frequencies to demonstrate its applicability in diverse microwave applications. It is shown in simulations and experimentally that the proposed MA is angularly stable up to 70˚and has polarization insensitivity behavior up to 90˚ for both TE and TM polarized waves. A good agreement between simulation and measurement results demonstrates the efficacy of the proposed MA in a wide range of microwave applications.

재질에 따른 애자의 절연내력특성 분석에 관한 연구

In general, insulator is a type of support used to fix and insulate an electric wire to a pylon or electric pole and is made of porcelain, glass, or silicone polymer in a power transmission line or a railway line. In transmission line applications, insulators are exposed to severe electrical and environmental conditions as well as insulation. Insulators are manufactured using various materials, and dielectric strength performance is different depending on the type of material. In this research, the dielectric strength characteristics of insulators according to insulation materials are analyzed by conducting electrical breakdown experiments and finite element method (FEM) analysis. Finally, the degradation characteristics of three types of insulators such as glass, porcelain, and polymer insulators are compared and analyzed through dry flashover and wet flashover experiments. In addition, electric field distribution analysis considering the type of insulator is analyzed by FEM simulation.

Analysis of Electric Field Distribution of Insulators YD-JZ 10 kV Oil-Immersed Transformers

The electric field distribution of the YD-JZ 10 kV oil-immersed transformer insulator is analyzed by COMSOL simulation, calculation, and actual measurement methods. The result shows that the first shed of the insulator accounts for 18% of the voltage drop. After that, the voltage of each umbrella skirt decreased gradually, and the proportion of voltage drop of the last two umbrella skirts increased again. The electric field of the insulator tip burr is 1.16 × 106 V/m; spherical burr is 2.84 × 105 V/m. The simulation result shows that the maximum electric field of spherical air gap defect in an insulator is 1.38 × 105 V/m; conical air gap defect is 1.61 × 105 V/m ; metal particle defect is 1.49 × 105 V/m. The simulated insulator umbrella skirt is covered with water. When the whole insulator umbrella skirt is short-circuited, there may be ground discharge. The measured results and simulation results show that the insulator can work normally if the umbrella skirt is not completely short-circuited.

Implementation of flexible virtual microchannels based on optically induced dielectrophoresis

Micro-nano particle manipulation methods in liquid environments have been widely used in the fields such as medicine, biology and material science. Nevertheless, the methods usually rely on pre-prepared physical microfluidic channels. In this work, virtual electrodes based on the optically induced dielectrophoresis (ODEP) method were used as virtual microchannels instead of traditional physical microfluidic channels. Virtual microchannels with different shapes were implemented by the designs of projected light patterns, which made the virtual microchannels have great flexibility and controllability. The theory of ODEP was verified by simulation and analysis of electric field distributions. The relationship between the manipulation force and the alternating current (AC) voltage or the AC frequency exerted on the cells was assessed. The experimental results indicated that the manipulation force was increased with the increase of the AC voltage, and it was reduced with the increase of the AC frequency. Moreover, different virtual microchannels were designed to carry out the transportation, aggregation and sorting of yeast cells and rat basophilic leukemia cells (RBL-2H3 cells) and the survival rate of the cells was evaluated. This work shows that the virtual microchannels can be flexibly realized by ODEP in liquid environments.

In-vivo estimation of tissue electrical conductivities of a rabbit eye for precise simulation of electric field distributions during ocular iontophoresis.

Precise estimation of electrical conductivity of the eyes is important for the accurate analysis of electric field distributions in the eyes during ocular iontophoresis. In this study, we estimated the tissue electrical conductivities of a rabbit eye, which has been widely employed for neuro-ophthalmological experiments, through an in vivo experiment for the first time. Electrical potentials were measured at multiple locations on the skin, while weak currents were transmitted into the skin via two surface electrodes attached to the skin around the eye. A finite element model was constructed to calculate the electric potentials at the measurement locations. The conductivity values of different tissues were then estimated using an optimization procedure to minimize the difference between the measured and calculated electric potentials. The accuracy of the estimated tissue conductivity values of the rabbit eye was validated by comparing the measured and calculated electric potential values for different electrode montages. Further multi-physical analyses of iontophoretic drug delivery to the rabbit eye showed a significant influence of the conductivity profile on the resultant particle distribution. Overall, our results provide an important reference for the tissue electrical conductivity values of the rabbit eye, which could be further utilized for designing new medical devices for delivering electric fields to the eyes, such as transorbital and transscleral electrical stimulations.

29.1: Invited Paper: Degradation Mechanism of High Mobility Oxide Thin Film Transistors for Next Generation Display

AC stress was applied to the IWZO thin film transistor with high mobility, and its deterioration phenomenon was observed. As a result, a rare phenomenon in which the ON current deteriorates was observed. A deterioration model was proposed by reference experiments using DC stress, emission analysis using an emission microscope, and electric field distribution analysis using a device simulator. It was concluded that the deterioration is due to hot carriers that occur when the gate electric field changes from ON to OFF.

Electric Field Distribution Analysis of Blood Cancer as a Potential Blood Cancer Therapy

Blood cancer causes a significant increase in the concentration of Leukocytes, which can be broken down through dielectrophoresis and electrochemical procedures. Therefore, the electric field plays an important role in the migration of leukocytes to high voltage areas. This is because different electrode arrangements produce varying electric field distributions. Furthermore, this study applied finite element methods to generate electric fields when electrodes with an AC voltage were applied to blood placed in a chamber. Therefore, in this study, variations of mediums and electrode arrangements were investigated, which led to the recommendation of 3 models. The objective was to investigate electrode arrangements that produce optimal electric field distribution for the three models to exhibit a booster of electric field distribution. The maximum electric field is generated close to the electrode (Z=2 mm and Z=92 mm) for any material (i.e. normal blood, B lymphocyte, and T lymphocyte) with values of 22.6 V/m and 23.47 V/m, 22.85 V/m and 22.97 V/m, and 24.88 V/m and 25.01 V/m. Based on principle, lymphocytes in the blood result in positive dielectrophoresis, since they migrate to a higher electric field close to the electrode, with enough input voltage to turn the electrochemical process on the leukocytes into electric current. Furthermore, this study provides new perspectives and ideas, which have not been revealed in previous studies on blood cancer therapy using the electric field of Ag electrode in blood cancer distribution.Keywords: blood cancer, dielectrophoresis, electric field, voltage, electrochemical, and cancer therapy.

FEM analysis of electric field distribution for polymeric insulator under different configuration of non-uniform pollution

Considering the extensive use of high voltage insulators, the reliable performance of insulators is challenged by various weather conditions such as pollution. According to recent researches under unidirectional wind, polymeric insulators are mostly exposed to non-uniform fan-shaped pollution. In many contamination patterns, the internal surface is covered with higher contamination than the external surface, and the non-uniform contamination shape on the insulator is similar to a ring-shape. In this paper, two conventional types of non-uniform pollution known as fan-shaped and ring-shaped are modeled for a 20 kV polymeric insulator, and a comparison is made in terms of the electric field between the two configurations using different thicknesses and electrical conductivity of the pollution layer. The electric field, during the arc length of the insulator, is studied under clean conditions, uniform contamination, and two types of non-uniform contamination. In addition, the effect of various thicknesses and conductivity of the pollution layer on the electric field distribution of this polymeric insulator is analyzed. The results show that the electric field distribution in non-uniform ring-shaped pollution is much more effective than the fan-shaped type by changing the thickness of the contamination layer. Moreover, ring-shaped pollution has a more uniform field distribution with fewer thicknesses of contamination layer.