Conductive Plate Research Articles

Analysis of the Influence of Electrostatic Probe on Surface Charge Measurements

The electrostatic probe is among the most popular methods to measure the surface charge. However, the probe influences the surface charge distribution on the sample, which increases measurement error. In this paper, the electrostatic probe system is modeled to study its effect on surface charges on a circular conductor plate using electrostatic field calculation. The influence of the probe on the sample surface charges is found to increase with a decrease in the measurement distance, whereas it has a similar effect on surface charge density at different radial positions. A calibration process is proposed to measure the potential from the induced potential of the probe head. Using the measured potential, we calculate the surface charge density via the method of moments. The measurement error is analyzed when the measurement distance and number of rings are changed. The authors find that the number of rings should be appropriately reduced when the measurement distance increases to ensure the accuracy of the calculations. This research provides theoretical guidance for using the electrostatic probe and establishing a surface charge measurements system. © 2022 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.

Design and Integration of Millimeter-Wave 5G and WLAN Antennas in Perfect Full-Screen Display Smartphones

Smartphone industries are seeking to maximize screen size, but a perfect full-screen phone is not yet available due to the unoccupied area required for the mobile antennas. Since a touchscreen is coated with transparent conductive layers, antennas below the touchscreen cannot create outward radiation. Accordingly, a non-metallic area is left for the antennas, which reduces the screen size. In this paper, we propose a design and integration of antennas for future millimeter-wave 5G smartphones to suit a perfect full-screen display. The proposed design consists of three modules, including a 1 × 12 patch antenna array at 28 GHz, a 1 × 8 patch array at 38 GHz, and a loop antenna at 2.45 GHz. The design environment consists of fully metallic top and bottom enclosures, mimicking the touchscreen and the printed circuit board, respectively. The three antennas were implemented on the flanks. Although the design area was limited and contained in parallel conductive plates, the three antennas still provided broad impedance bandwidths (26.5–32.0 GHz, 35.2–42.0 GHz, and 2.41–2.48 GHz) and high gains (16.7 dBi, 16.4 dBi, and 4.3 dBi). The isolation was larger than 20 dB, and the scanning ranges were ±45°. The proposed scheme is the first antenna system designed for perfect full-screen display phones.

Electro-assisted printing of soft hydrogels via controlled electrochemical reactions

Hydrogels underpin many applications in tissue engineering, cell encapsulation, drug delivery and bioelectronics. Methods improving control over gelation mechanisms and patterning are still needed. Here we explore a less-known gelation approach relying on sequential electrochemical–chemical–chemical (ECC) reactions. An ionic species and/or molecule in solution is oxidised over a conductive surface at a specific electric potential. The oxidation generates an intermediate species that reacts with a macromolecule, forming a hydrogel at the electrode–electrolyte interface. We introduce potentiostatic control over this process, allowing the selection of gelation reactions and control of hydrogel growth rate. In chitosan and alginate systems, we demonstrate precipitation, covalent and ionic gelation mechanisms. The method can be applied in the polymerisation of hybrid systems consisting of more than one polymer. We demonstrate concomitant deposition of the conductive polymer Poly(3,4-ethylenedioxythiophene) (PEDOT) and alginate. Deposition of the hydrogels occurs in small droplets held between a conductive plate (working electrode, WE), a printing nozzle (counter electrode, CE) and a pseudoreference electrode (reference electrode, RE). We install this setup on a commercial 3D printer to demonstrate patterning of adherent hydrogels on gold and flexible ITO foils. Electro-assisted printing may contribute to the integration of well-defined hydrogels on hybrid electronic-hydrogel devices for bioelectronics applications.

Tailoring the effects of interface physics on the free vibration of graphene-boron nitride heterostructure

In electronics, inductive capacitors are made by two conductive plates, which are filled with non-conductive material between them. In this study, the graphene nano-sheet is utilized as capacitor plates and boron-nitride nano-sheet as its filler, and the effect of interface type of that of nanostructures on the vibrational properties of nanocapacitor has been studied using Molecular Dynamics (MD) approach. For this purpose, different interface types of graphene and boron-nitride nano-sheets are studied, including; CB66NC, CB68BC, CB88BC, CB108BC, CB1010NC, CN88NC, CN108NC, and CN1010NC. For the MD simulation, the LAMMPS software is implemented. The obtained results showed that CB66NC has the highest natural frequency and this is the most comfortable interface type to fabricate nano-capacitors, from a vibrational perspective. Furthermore, the CB66NC has the most stable because the hexagonal connection interface is more stable than the octagonal and decagonal, and the Carbon-Nitrogen bond energy which is used in the CB66NC interface type is higher than the Carbon-Boron bond energy.

Accurate Measurement of the Contact Resistance During Internal Short Circuit in Lithium-Ion Batteries

Accurate internal short circuit (ISC) resistance measurement is of vital importance to understanding and modeling the ISC process and consequent thermal runaway (TR) behaviors. The current measurement of ISC resistance usually cannot quantify the contact resistance of two directly-involved parties for the ISC, and the measured ISC resistance generally contains additional components (depending on the ISC modes). To this end, we propose a novel experimental methodology to accurately quantify the contact resistance during ISC. By a series of auxiliary experiments, we exclude the resistance contribution from non-direct-contact components (but are directly contacted with the direct-involving parties). Two representative scenarios of ISC, i.e., direct contact of electrodes and contact of conductive metallic plates with electrodes, are characterized by the proposed methodology. An additional ISC scenario is used to validate the effectiveness and accuracy of the proposed methodology. Results provide a powerful tool to characterize the contact resistance during ISC for future possible experiment design and theoretical modeling for the understanding of battery safety issues.

Simulation of an induction flow water heater based on a multifunctional integrated electromagnetic component

Water supply plays an important role in the development of the agricultural sector. Maintaining the temperature when watering plants is essential for proper growth. The water must be warm if it is watering overhead or is carried out with a large volume of water at a time. In the article, the authors propose an effective induction instantaneous water heater using functional integration methods. The modeling of the pipeline heating process was carried out in the Elcut software package, the results of the thermal problem of the model were obtained. The article presents a diagram of an induction instantaneous water heater based on a multifunctional integrated electromagnetic component (MIEC), made of two conductive plates separated by a dielectric and rolled into a roll. This technology makes it possible to reduce the weight and dimensions of the system and increase its reliability.

Explosive technologies for testing composite constructions of aircraft for strength to heat-power non-stationary loading

Sets of explosive and heating devices for experimental study of strength of composite constructions of aircraft against complex thermal and mechanical action of radiation and particles fluxes of different physical nature are considered. Two new explosive devices for generating low-pulse loads of microsecond duration are proposed. Devices based on thermoelectric heating elements, conductive plates and pyrotechnic compositions applied to the surface of the tested structure have been developed to simulate thermal action of radiation and particles fluxes. A universal test bench using these sets of devices has been developed. This test bench allows testing the strength of composite constructions to the joint action of thermal and mechanical loads having given space-time distributions.

МОДЕРНИЗИРОВАННАЯ УСТАНОВКА ДЛЯ ФИЗИЧЕСКОГО МОДЕЛИРОВАНИЯ ПРОМЫВКИ ЗАСОЛЕННЫХ ПОЧВ

The purpose of the study is to improve the design of the installation through the use of soil moisture concentration sensors and digital LCR meter XJW01. The digitalization of hydrotechnical melioration of agricultural lands in the Russian Federation requires the active use of mathematical models for the movement of moisture fl ows, nutrients, air, and heat in the soil profile. The parameters of these flows in the laboratory are determined by the methods of physical modeling. Improving the design of installations for the physical modeling of soil processes increases the accuracy of measurements and reduces the labor intensity of work. The modernized facility for physical modeling of saline soil leaching includes electrical sensors for measuring the concentration of soil moisture. The sensors are equipped with conductive plates and conductive windings. Digital LCR meter XJW01 automatically detects the sensor as an electrical oscillatory circuit and fixes its quality factor. The quality factor of the sensor depends on the concentration of soil moisture that fi lls its body. The operating prototype of the installation was tested. In the concentration range of NaHCO3 solution from 0 to 350 mmol/dm3 , the quality factor of the sensors varies from 282±2.1 to 221±2.7 (signifi cance level P = 0.99, number of degrees of freedom k = 4, and Student’s test t = 4.60).

A Sensor Topology for Noncontact AC Voltage Measurement of Polyphase Cables

This paper presents a sensor topology and signal processing technique for non-contact measurement of polyphase line-to-line voltage. Conductive plates around the exterior of a three-phase cable form a circuit that can be used to disaggregate the ac voltages in the cable. Fully-differential transimpedance amplifiers detect capacitive currents that can be related mathematically to line-to-line voltages. Sensor calibration and line-to-line voltage reconstruction results are presented.

Additive manufacturing of lithium aluminosilicate glass-ceramic/metal 3D electronic components via multiple material laser powder bed fusion

Multiple material additive manufacturing technology with the capability to integrate glass-ceramic and metallic materials is essential to the development of high-performance functional components for high temperature applications. Here we show the feasibility and characteristics of additively manufactured glass-ceramic/metal 3D electronic components via single-process multiple material laser powder bed fusion (MMLPBF). Copper (II) oxide (CuO) powder is mixed with α-spodumene (lithium aluminosilicate, Li 2 O·Al 2 O 3 ·4SiO 2 ) glass-ceramic powder to improve the laser absorbance, reduce the melting point of glass-ceramic to match that of copper and to improve bonding between copper and the glass-ceramic. Up to 92% relative density of the glass-ceramic is realized. The monoclinic crystal α-spodumene has been transformed to tetragonal crystal β-spodumene after laser melting. Sodium chloride (NaCl) and graphite mixed powder is printed as the substrate for the glass-ceramic component for its rapid removal. Embedded conductive copper wires and plates as the main conductive structures are successfully built within the glass-ceramic from powder feedstocks. The electrical resistivity of the printed copper structures is examined. An embedded multiple layer electric circuit, a capacitor and a temperature sensor are successfully printed and tested. • First demonstration of printing glass-ceramic/metal 3D electronic components via LPBF. • Copper oxide is added to the glass-ceramic powder to tune the material property. • Salt is used as the interface layer to the base plate for ease of removal. • 3D circuit, capacitor and temperature sensor are imbedded in the glass/ceramic.

Model-Based Reconstruction of 2-D Geometrical Features Using Eddy Current Testing

This article presents a model-based eddy current (EC) testing method for the reconstruction of geometrical features, that may be hidden, through, or blind cavity in a large electrically conductive plate. Based on a distributed current source (DCS) modeling method, a perturbation model is formulated to convert the feature reconstruction problem into finding a possibility vector using a finite set of measured magnetic flux density (MFD) data and solved with the Tikhonov regularization method. The proposed method is numerically and experimentally validated and demonstrated by using the specimens with compound conductive/nonconductive geometrical features and comparing them with two published feature detection methods. Parametric studies are conducted to analyze the effects of feature shape, sensor configuration, and multi-coil excitation on reconstruction accuracy.

Termoelektrik Soğutucunun Modelleme Çalışması ve Performans İncelemesi

Thermoelectric refrigerators are widely used in electronics, medical, and food industry application areas. A refrigeration effect can also be achieved without using any moving parts by merely passing a small current through a closed circuit made up of two dissimilar materials. This effect is called the Peltier effect, and a refrigerator that works on this principle is called a thermoelectric refrigerator. They consist of several thermoelectric legs sandwiched between two thermally conductive plates, one cold and one hot. Thermoelectric refrigerators presently cannot compete with the vapor-compression refrigeration system because of their low- coefficient of performance (COP). However, some applications have been preferred because of their small size, simplicity, quietness, and reliability. In this study, a thermoelectric cooler having a maximum cooling power of 50 W, having a dimension of 40mmx40mmx3.6 mm, is modeled in multi-physics software. Also, the performance of a thermoelectric refrigerator is investigated. It is computed the temperature difference between ceramics plates versus electric current and COP for a temperature difference between ceramics plates. The simulation results are compared with experimental data. The data obtained from the analyses have been compared with the experimental results and found to agree with each other. For the surface temperatures of 25 oC and 50 oC, the maximum coefficients of performance have been computed to be 1.091 and 1.445, respectively. In general, as the temperature of hot surfaces has increased for the same temperature differences, the COP of the thermoelectric cooler has increased.

Iron loss estimation of soft magnetic materials for power transformers considering hysteretic properties

AbstractThis paper investigates an efficient iron loss calculation method for soft magnetic materials of power transformers. To accurately estimate iron losses in the materials such as structural steels and magnetic shielding, the magnetic field analysis taking account of the nonlinear magnetic properties is considered to be effective. In this paper, quasi‐DC magnetic properties of the soft magnetic materials are measured and the iron losses are calculated by using a three‐dimensional finite element method. Furthermore, the effect of considering hysteretic properties on the accuracy of the iron loss calculation is discussed based on a theoretical representation of eddy current loss in a conductive rectangular plate.

Pull-in Phenomenon in the Electrostatically Micro-switch Suspended between Two Conductive Plates using the Artificial Neural Network

Artificial Neural Networks (ANN) are designed to evaluate the pull-in voltage of MEMS switches. The mathematical model of a micro-switch subjected to electrostatic force is preliminarily illustrated to get the relevant equations providing static deflection and pull-in voltage. Adopting the Step-by-Step Linearization Method together with a Galerkin-based reduced order model, numerical results in terms of pull-in voltage are obtained to be employed in the training process of ANN. Then, feed forward back propagation ANNs are designed and a learning process based on the Levenberg-Marquardt method is performed. The ability of designed neural networks to determine pull-in voltage have been compared with previous results presented in experimental and theoretical studies and it has been shown that the presented method has a good ability to approximate the threshold voltage of micro switch. Furthermore, the geometric and physical effect of the micro-switch on the pull-in voltage was also examined using these designed networks and relevant findings were provided.

Identifying inclusions in a non-uniform thermally conductive plate under external flows and internal heat sources using topological optimization

We propose applying topological optimization methods based on measuring temperature and heat fluxes to estimate the thermal conductivity of inhomogeneous thermally conductive plates and determine the shape and location of foreign inclusions. Examples of plates subjected to external heat fluxes and heat sources are considered. The solutions are obtained with the help of the finite element method combined with the method of moving asymptotes. The results show that identification accuracy depends on the defined boundary conditions, the source intensity value, heat fluxes, temperature distribution and the shape of the inclusions. For the problem of 18 circular inclusions under different heat fluxes, identification accuracy increases with increasing source intensity values.

Design and Performance of Additively Manufactured In-Circuit Board Planar Capacitors

This article discusses the design and performance of planar capacitors built as pairs of conductive plates by additive manufacturing as part of an electronic circuit board. This article covers several geometries and layers of parallel plates that allow for different capacitance values, from a few picofarads (pF) to several nanofarads (nF). The dc, ac, and radio frequency (RF) characterization demonstrated superior performance compared to off-the-shelve surface mount device (SMD) capacitors up to 20 GHz. The additively manufactured capacitors exhibit breakdown voltages in excess of 1 kV and subpicoampere leakage currents, while the change in RF impedance changes, as a function of frequency, is a factor of $3\times $ smaller than SMD capacitors.

Modeling and Injection Molding of Electrically Conductive Polymer Composite Bipolar Plates

In this work, we are exploring electrically-conductive polymer composites as an alternative to the traditional metal alloys commonly used for fuel cell bipolar plates. Polymer composites can reduce both the weight and cost of the bipolar plate, while still providing sufficient electrical properties. The main objective of this research is to model and injection mold polymer composites that will meet the United States Department of Energy technical target for bipolar plate electrical conductivity (> 100 S/cm). A micromechanical model was developed to predict conductivity based upon direction in the material, fiber alignment, fiber length and diameter, fiber concentration, and fiber conductivity. The conductivity predictions of this model were then compared to injection molded samples. For these samples, conductive fillers (carbon fiber and carbon nanotubes) were added to nylon at weight percentages ranging from 0 to 50%, and conductivity was measured experimentally using a four-point probe method. The analytical and experimental results show good correlation over this range of filler weight percentages. Conductivities greater than 250 S/cm were achieved, exceeding the DOE technical target. Ultimately, the combined modeling and experimental results presented here demonstrate the potential for using polymer composite bipolar plates in fuel cells.

A Deeper Insight into the Influence of the Electric Field Strength When Melt‐Electrowriting on Non‐Planar Surfaces

AbstractDefined structures for tissue engineering can be achieved by a variety of techniques, one of which includes melt‐electrowriting (MEW), a technology that deposits spatially defined microfibers of a molten polymer across an electric field. In this study, the authors investigate how to microfabricate biomaterial‐meshes using MEW to non‐planar surfaces that will have more applicability to anatomical structures. By modeling the electric field strength associated with MEW, it is found that incorporation of a non‐conductive 3D printed mould on the conductive collector plate offers the ability to accurately print patterns on non‐planar surfaces successfully. Importantly, if the applied voltage at the nozzle or collector plate is kept constant in the MEW process, the electrostatic behavior of the deposited polymer, and the electric field strength between the collector and nozzle (which is greatest at the nozzle) has the greatest impact on the accuracy of fiber patterning and stacking. Consequently, controlled fiber deposition is exhibited, provided that a constant voltage and a constant vertical distance between the nozzle and the mould are maintained. Overall, this study establishes the groundwork to support further developments in MEW technologies, from flat to anatomically relevant 3D structures in the fields of regenerative medicine and biofabrication.

A Review of the Current State of Technology of Capacitive Wireless Power Transfer

Wireless power transfer allows the transfer of energy from a transmitter to a receiver without electrical connections. Compared to galvanic charging, it displays several advantages, including improved user experience, higher durability and better mobility. As a result, both consumer and industrial markets for wireless charging are growing rapidly. The main market share of wireless power is based on the principle of inductive power transfer, a technology based on coupled coils that transfer energy via varying magnetic fields. However, inductive charging has some disadvantages, such as high cost, heat dissipation, and bulky inductors. A promising alternative is capacitive wireless power transfer that utilizes a varying electric field as medium to transfer energy. Its wireless link consists of conductive plates. The purpose of this paper is to review the state of the art, link the theoretical concepts to practical cases and to indicate where further research is required to take next steps towards a marketable product. First, we describe the capacitive link via a coupling model. Next, we highlight the recent progress in plate topologies. Additionally, the most common compensation networks, necessary for achieving efficient power transfer, are reviewed. Finally, we discuss power electronic converter types to generate the electric field.

Stability control of permanent magnet and electromagnetic hybrid Halbach array electrodynamic suspension system

Purpose The purpose of the paper is to study the stability control of permanent magnet (PM) and electromagnetic hybrid Halbach array electrodynamic suspension (EDS) system because of the poor suspension stability caused by the well-known under-damped nature of PM EDS system. The adjustment control is realized by PM and electromagnetic hybrid Halbach array, which is composed by winding active normal conductor coils on PM surface. Design/methodology/approach The three-dimensional (3-D) electromagnetic force analytical expression of PM and electromagnetic hybrid Halbach array EDS system for a nonmagnetic conductive plate is derived. And the accuracy of the derived equations is verified by a 3-D finite-element model (FEM). Basing on the 3-D levitation force expression, an acceleration feedback suspension controller is designed to suppress the vibration of PM EDS system, and the suspension stability of the system under the track and load disturbance was simulated and analyzed. Findings The 3-D electromagnetic force comparison of analytical model and FEM are in good agreement, which verifies the correctness of the analytical expression. The simulation results show that the acceleration feedback suspension controller can make the system have good suspension stability under the external disturbance. So it proved that the PM and electromagnetic hybrid Halbach array EDS system can overcome the poor suspension stability caused by the under-damped nature of PM EDS system through the designed acceleration feedback suspension controller. Originality/value This paper designed an acceleration feedback suspension controller to suppress the vibration of PM and electromagnetic hybrid Halbach array EDS system under external disturbance, basing on the derived levitation force analytical expression. And the simulation results show that the acceleration feedback suspension controller can make the system have good suspension stability under the external disturbance.