Capacitive Elements Research Articles

A Seawater Conductivity Measurement Method Based on Magnetic Resonance Coupling

This paper proposes a magnetic resonance coupling seawater conductivity measurement method with a dual-coil structure. The passive transceiver coil is composed of two detection coils and capacitive elements placed in seawater. The seawater conductivity measurement is realized by analyzing the relationship between the transmission loss of the resonant magnetic field between the passive transceiver coils in the seawater and the seawater conductivity. In the article, the magnetic resonance coupling measurement method is established and analyzed, the circuit model of the magnetic resonance coupling measurement system transmitted in seawater is established, the experimental device is set up for laboratory testing, and the corresponding test situation is simulated by finite element electromagnetic modelling. The test and simulation results show that the measurement method is feasible; the system has the best performance at the resonant frequency, especially for low-conductivity conditions, and better sensitivity. In addition, the resonant frequency increases, and the conductivity resolution of the measurement system for seawater increases.

Study on Space Charge Characteristics in XLPE Under DC Voltage Superimposed by Impulse Voltage

In direct current (dc) transmission lines, power cables are susceptible to the invasion of switching overvoltage or lightning overvoltage. This causes the accumulation of space charge in the insulation due to the higher transient composite electric stress. Space charge is an important factor in dielectric breakdown, especially under high electric stress. However, until now, there are few reports on space charge characteristics under the composite stresses of dc voltage and impulse voltage. In this article, a modified pulsed electroacoustic space charge measurement system used for dc voltage superimposed by impulse voltage is developed by reasonably choosing resistor and capacitor elements in the measuring system. Then, space charge characteristics in cross-linked polyethylene (XLPE) are measured under dc voltage, impulse voltage, and dc voltage superimposed by impulse voltage. The test results show that hetero-charges dominated in the XLPE bulk under a positive dc voltage, whereas homo-charge injection occurred from the semiconductor (SC) electrode under a negative dc voltage. However, a continuous impulse voltage with high amplitude can cause a large degree of homo-charge injection from both electrodes. Moreover, greater homo-charge injection appeared under the negative impulse voltage than that under the positive impulse voltage. Under a dc voltage superimposed by an impulse voltage, the superposition of voltages with the same polarities facilitated homo-charges injection from both electrodes to a greater extent than did the superposition of voltages with opposite polarities. Furthermore, regardless of the polarity of the applied dc voltage, greater space charge accumulation appeared in XLPE when a negative impulse voltage is superimposed.

Novel Nth/2Nth Order Two-Band Bandpass Filters for Sub-6 GHz 5G Applications

In this paper, a new design method is proposed for multi-mode two-band bandpass filters based on combining a square loop resonator that has a capacitive perturbation element and short-circuited stubs. This concept is a new multi-mode two-band filter design having Nth and 2Nth order for the first and second passbands that appear in f0 and 3f0 center frequencies, respectively. It has been shown that the number of transmission modes in each passband can easily be increased by periodically cascading one unit filter cell including one square loop resonator and two short-circuited stubs. This also provides a reconfigurable filter property, namely the obtaining of two different filtering characteristics in the second passband by means of the reverse and straight placing of the cascaded unit filter cells in the horizontal axis. Two 2nd/4th order two-band bandpass filter prototypes are fabricated and tested to validate the proposed design method. The total surface areas of these fabricated prototypes are 26.0 mm × 9.0 mm and 24.4 mm × 16.8 mm, and the measured insertion losses in the first/second passband are about 0.63 dB/0.96 dB and 0.59 dB/0.83 dB. It is observed that the filter prototypes have the advantages of low insertion loss, compact size, and flexible filtering characteristics. The designed filters are suitable for operation in the 5G spectrum, which includes a range of radio frequencies sub-6 GHz.

МОДЕЛИРОВАНИЕ ЕМКОСТНОГО ДАТЧИКА ДЛЯ РЕГИСТРАЦИИ ЧАСТИЧНЫХ РАЗРЯДОВ В СИЛОВОМ КАБЕЛЕ

The article discusses the simulation of a partial discharge (PD) pulse in a power single-core coaxial cable using a capacitive sensor. The sensor provides capacitive coupling to the test sample and its capacitive element is in fact part of the total capacitance of the cable. The resistive element added to the design makes it possible to register current pulses of partial discharges. At the same time, the used sensor has no connection with high-voltage electrodes of the systems, which is its undoubted advantage in comparison with conventional capacitive sensors.

The influence of sintering condition on microstructure, phase composition, and electrochemical performance of the scandia-ceria-Co-doped zirconia for SOFCs

Samples of 6 mol% Sc2O3 - 1 mol% CeO2 co-doped ZrO2 were fabricated by conventional ceramic processing methods and sintered at various temperatures from 1000 to 1650?C in air. The sintering conditions on microstructure and phase content are investigated using various characterization methods, including pycnometry, diffraction, and spectroscopy. The electrical conductivity of samples was investigated using electrochemical impedance spectroscopy (EIS). The effect of inductive load (measured from room temperature to 800?C) is discussed in low to high temperature regimes. At T<400?C since the arc is not a complete semicircle, the high-frequency arc could be fit using a constant phase element (CPE), while by subtraction of inductive load, a good fit is achieved using a capacitor element instead of CPE. The Arrhenius conductivity plot of samples reveals that the specimen sintered at 1600?C for 6 hours exhibits the highest conductivity. The activation energy (Ea) and conductivity preexponential (?0) factor are calculated from a linear fit to data that decreases by the increase in sintering temperature.

Low Cost Brix Measurement System for Grapes using Arduino Uno

When grapes are at their peak sugar content for harvest, brix measurements play a main role in determining. Refractometers are a common instrument used to measure the content of sugar in the solution. Its main drawback is that it requires liquid or a solution of grapes or fruits and is a manual method. So, to avoid the distraction of grapes or fruits, this low-cost Arduino-based brix measurement system is designed and developed. The system contains a capacitive sensing element, signal conditioning, and signal processing. This paper exemplifies a brix computing system that uses an Arduino Uno as the controller and a capacitive sensor element to continuously detect the capacitance, dielectric constant, and brix level of grape which is displayed on a serial monitor of Arduino software. The time constant of the capacitor is a key component of the Arduino capacitance meter. The charge and discharge cycles of the capacitor take longer when the capacitance is higher. After signal conditioning, charging and discharging voltages of the capacitive sensor are given to an Arduino Uno. It has a percentage accuracy of 99%. This developed system is cost-efficient and handy.

Droplet-Dispensed Graphene Oxide as Capacitive Sensing Elements for Flexible Pressure-Pulse Sensing Array

We report a novel flexible capacitive pressure-pulse sensor array developed by integrating droplet-dispensed graphene oxide (GO) sensing elements and flexible electronics. The utilization of droplet-dispensing technology enables the fabrication multiple capacitive sensing elements rapidly while producing sensitive pressure sensors with excellent repeatability. The dispensed droplet volume (GO aqueous dispersion) ranged from around 33.5 to 65.4 pL with diameter ranging from 40 to 50 μm. The size (i.e., footprint and dielectric material thickness) of a sensing element can be controlled by the total GO dispersed per droplet. The fabrication process and preliminary characterization of these GO capacitive sensors are discussed in this paper. Thus far, we have shown that these sensors have a sensitivity of ∼10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−3</sup> kPa <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−1</sup> , with the relative permittivity of the dispensed GO being ∼6 (measured at a frequency of 600 kHz). We have also demonstrated that the printed sensing elements can be used for human wrist pulse sensing. Hence the technology described in this paper could potentially be used in wearable electronics for healthcare applications.

Effectiveness of c-Axis Aligned Crystalline IGZO FET as Selector Element and Ferroelectric Capacitor Scaling of 1T1C FeRAM

Effectiveness of <i>c</i>-Axis Aligned Crystalline IGZO FET as Selector Element and Ferroelectric Capacitor Scaling of 1T1C FeRAM

Flexible integrated sensor with asymmetric structure for simultaneously 3D tactile and thermal sensing

The human body detects tactile stimuli through a combination of pressure force and temperature signals via various cutaneous receptors. The development of a multifunctional artificial tactile perception system has potential benefits for future robotic technologies, human-machine interfaces, artificial intelligence, and health monitoring devices. However, constructing systems beyond simple pressure sensing capabilities remains challenging. Here, we propose an artificial flexible and ultra-thin (50 μ m) skin system to simultaneously capture 3D tactile and thermal signals, which mimics the human tactile recognition process using customized sensor pairs and compact peripheral signal-converting circuits. The 3D tactile sensors have a flower-like asymmetric structure with 5-ports and 4 capacitive elements in pairs. Differential and average signals would reveal the curl and amplitude values of the fore field with a resolution of 0.18/mm. The resistive thermal sensors are fabricated with serpentine lines and possess stable heat-sensing performance (165 mV/°C) under shape deformation conditions. Real-time monitoring of the skin stimuli is displayed on the user interface and stored on mobile clients. This work offers broad capabilities relevant to practical applications ranging from assistant prosthetics to artificial electronic skins.

Wireless Capacitive Liquid-Level Detection Sensor Based on Zero-Power RFID-Sensing Architecture.

In this paper, a new method for the wireless detection of liquid level is proposed by integrating a capacitive IDC-sensing element with a passive three-port RFID-sensing architecture. The sensing element transduces changes in the liquid level to corresponding fringe-capacitance variations, which alters the phase of the RFID backscattered signal. Variation in capacitance also changes the resonance magnitude of the sensing element, which is associated with a high phase transition. This change in the reactive phase is used as a sensing parameter by the RFID architecture for liquid-level detection. Practical measurements were conducted in a real-world scenario by placing the sensor at a distance of approximately 2 m (with a maximum range of about 7 m) from the RFID reader. The results show that the sensor node offers a high sensitivity of 2.15°/mm to the liquid-level variation. Additionally, the sensor can be used within or outside the container for the accurate measurement of conductive- or non-conductive-type liquids due to the use of polyethylene coating on the sensitive element. The proposed sensor increases the reliability of the current level sensors by eliminating the internal power source as well as complex signal-processing circuits, and it offers real-time response, linearity, high sensitivity, and excellent repeatability, which are suitable for widespread deployment of sensor node applications.

Implementation and Experimental Verification of Resistorless Fractional-Order Basic Filters

Novel structures of fractional-order differentiation and integration stages are presented in this work, where passive resistors are not required for their implementation. This has been achieved by considering the inherent resistive behavior of fractional-order capacitors. The implementation of the presented stages is performed using a current feedback operational amplifier as active element and fractional-order capacitors based on multi-walled carbon nano-tubes. Basic filter and controller stages are realized using the introduced fundamental blocks, and their behavior is evaluated through experimental results.

A Universal Electronically Controllable Memelement Emulator Based on VDCC with Variable Configuration

In this paper, a universal fractional order memelement (FOME) emulator is proposed based on the use of a voltage differentiating current conveyor (VDCC) as active block. The emulation circuit was implemented without an analog voltage multiplier and with only one type of grounded passive element—capacitors. Specially designed switching networks allow controlling the type of memelement and the emulator mode—floating or/and grounded, electronically controlled (by changing the bias voltage of the VDCC) FOMEs. The proposed emulator was theoretically analyzed, and the influence of possible non-idealities and parasitic effects was also been analyzed to reduce the undesirable effects by selecting the passive circuit elements. The proposed designs are very simple compared to most of the designs available in the literature and can operate in a wide frequency range (up to 50 MHz) and also satisfy the non-volatility test. All realized memelements can be used in incremental and decremental modes as well as in inverse configuration. The performance of the circuit was verified by HSPICE simulations using 0.18 μm TSMC process parameters and ±0.9 V power supply. The proposal is also supported by experimental results with off-the-shelf components (LM13700 and one AD844) in order to confirm the proposed solution’s workability.

Glasses frame‐based wearable antenna design for ultrahigh frequency radio frequency identification and Internet of Things applications using characteristic mode analysis

A novel ultra-high frequency (UHF) radio frequency identification (RFID) passive tag antenna based on a glasses frame is proposed for Internet of Things (IoT) applications. The glasses frame structure is exploited using characteristic mode analysis (CMA) to explore different modes for both 900 MHz and 2.4 GHz frequency bands. The proposed design consists of a glasses metallic frame and a loop for conjugate matching with an RFID chip (Alien Higgs H4). First of all, an already manufactured glasses metal frame structure is simulated in Computer Simulation Technology (CST) Microwave studio using CMA to get CM modes in the required RFID band. After that, a small loop is used along with the RFID chip as a capacitive coupling element to excite modes at 900 MHz by placing it at current minima. Moreover, the proposed tag antenna is also simulated with the voxel head model in CST and there is no significant change in impedance and reflection coefficient. The simulated specific absorption rate (SAR) is 0.5 W/Kg. Furthermore, the tag design is simulated with different glass materials and also with different frame structures to prove the robustness of the proposed solution. This tag design covers the entire US UHF RFID band (902–928 MHz) and features a read range of 2 m, measured using a UHF RFID reader setup with 4 W EIRP. Therefore, this antenna design can be a good candidate for future IoT technologies such as RFID, long range (LoRa), and other IoT applications.

Nanocomposites of PVA/chitosan blend with BiOCl:Eu3+ prepared by sonochemical route: Forensic and optoelectronics applications

Polymers of chitosan (CS) and polyvinyl alcohol (PVA) were combined effectively to create a synergetic property of both. To this composite, BiOCl:Eu3+ nanoparticles (NPs) were used as an appropriate filler. Vitamin B2 (VB2) was used as a biosafe coupling agent to modify the surface of NPs. Different weight percentage of BCE (50, 100, and 150 wt%) were then created using a casting/solvent evaporation process after being exposed to ultrasonic irradiations. The compatibility of NPs with the blend polymer were enhanced due to the coupling agent. Optical absorbance and thermal stability of compounds were impacted by inserting the modified NPs into the blend polymer. The hydrophilicity reduced for various ratios of the modified NPs loaded in the blend polymer, according to the contact angle measurements. The characteristic emission peaks of Eu3+ ions were observed at 581, 594, 621, 652, and 698 nm after being stimulated by 466 nm. With increased surface modifier concentration, the chromaticity diagram showed that emission colors altered from red to deep red. Reduced space charge polarization of the dipoles was shown to be the cause of the dielectric constant decreasing with frequency. The various resistive and capacitive elements of the produced materials are credited with the non-Debye type relaxation process. The level I-III ridge details are visible in the colorimetric images of fingerprints using the optimized nanofiller in polymer matrix on forensic-related surfaces. The aforementioned results made it abundantly evident that the improved NCs are very beneficial in multidimensional applications.

Computational capacity of LRC , memristive, and hybrid reservoirs

Reservoir computing is a machine learning paradigm that uses a high-dimensional dynamical system, or reservoir, to approximate and predict time series data. The scale, speed, and power usage of reservoir computers could be enhanced by constructing reservoirs out of electronic circuits, and several experimental studies have demonstrated promise in this direction. However, designing quality reservoirs requires a precise understanding of how such circuits process and store information. We analyze the feasibility and optimal design of electronic reservoirs that include both linear elements (resistors, inductors, and capacitors) and nonlinear memory elements called memristors. We provide analytic results regarding the feasibility of these reservoirs and give a systematic characterization of their computational properties by examining the types of input-output relationships that they can approximate. This allows us to design reservoirs with optimal properties. By introducing measures of the total linear and nonlinear computational capacities of the reservoir, we are able to design electronic circuits whose total computational capacity scales extensively with the system size. Our electronic reservoirs can match or exceed the performance of conventional "echo state network" reservoirs in a form that may be directly implemented in hardware.

Development of a Semiconductor Time Relay for Locomotives

Purpose. The need to replace the outdated element base of locomotive electrical apparatuses is urgent under conditions of locomotive overhaul to extend their service life. The main aim of the work is to reduce costs for the operation and repair of rolling stock by increasing the reliability of electrical apparatuses, the introduction of unified technical solutions. Methodology. Using the system-historical approach, the advantages and disadvantages of the main design principles of electrical apparatuses of locomotives are found out. The improvement directions of the elemental base of the time relay have been determined. The need to develop unified technical solutions for the implementation of locomotive time relays is substantiated. Using the methods of applied theory of digital machines and circuit engineering, a semiconductor time relay for locomotives was developed, which provides the possibility of implementing 23 options for time delay without changing the relay design. The proposed methodology allows designing universal electronic relays with any ranges of time delays. A combination of binary counters and a multiplexer is used as the main elements of the time delay control. The absence of elements of control capacitance and active resistance (RC circuits) in the scheme of the proposed semiconductor time relay allows ensuring the stability of the time relay characteristics over the entire operating interval, reducing the maintenance and repair costs of electrical apparatuses. Findings. A unified time relay with a wide range of time delay and the possibility of connecting electrical circuits of locomotives with a supply voltage of 50 and 110 V has been developed. The obtained results make it possible to predict the further development of semiconductor time relays and to apply the developed semiconductor (electronic) time relay for all types of railway rolling stock. Originality. In the work, the development of technologies and the element base of locomotive electrical apparatuses were analysed. The need to improve the element base of electrical apparatuses is substantiated using a time relay example. Practical value. Based on the proposed technical solutions, it is possible to produce a universal semiconductor time relay for locomotives.

Self-Powered Signal Transduction of Ion-Selective Electrodes to an Electronic Paper Display.

Mobile integrated electrochemical sensors normally require a power supply for operation. Unfortunately, the practice of discarding batteries associated with these devices runs counter to our desire for a sustainable world. Self-powered sensing concepts that draw the energy directly from the measurement itself would overcome this limitation. Potentiometric sensors for the measurement of pH, many electrolytes, and gases are ubiquitous in analytical practice. However, in potentiometry, the voltage is acquired in the absence of current flow, making it seemingly impossible to draw power. Fortunately, it has been recently established that transient currents may be tolerated across potentiometric measurement cells to charge a capacitive or electrochromic element such as Prussian blue integrated in the measurement cell and whose absorbance then directly follows the potential changes in a reversible manner. We have shown here that commercial electronic paper (e-paper), widely used to make electronic ink and ebook readers, can directly be driven by a potentiometric measurement cell in a reversible manner at mild potentials of >100 mV typical for such sensors. The capacitance of the e-paper pixel studied here was found to be 0.53 μF mm-2, 30 times smaller than that of Prussian blue films. The colorimetric absorbance of the e-paper was also more stable (observed drift over 2 h corresponding to 0.76 mV h-1) and reproducible (corresponding to 1 mV standard deviation). The e-paper pixel was directly driven by a polymeric pH electrode as a model system. Choosing a basic inner solution (pH 12.9) behind the membrane gave sufficiently positive cell potentials for driving visible absorbance change in a sample pH range of 4-10, while a more acidic pH of 3.4 and alternating the connections to the e-paper were more suited for more basic samples of pH > 10. This convenient and cost-effective approach makes it possible to directly drive an optical display from the potentiometric measurement itself and should be suitable for moderate sensing membrane resistances of less than about 100 kΩ, depending on the area of the chosen pixel.

Magnetic and optical properties, electrical behavior and conduction mechanism study by CBH model of Cu(HAsO3).Te(OH)6 compound

The copper hydrogeno-arsenite tellurate material (CuAsTe) was synthesized and its magnetic properties were investigated. Thermal analyses revealed that no mass loss was recorded before 480 K. Additionally, in this current work, electrical properties based on the impedance measurements were determined. The complex impedance diagram at different temperatures demonstrated a single semicircle, implying that the response originated from a single capacitive element corresponding to the grains. The thermal evolution of the conductivity σdc displayed an Arrhenius type behavior and suggested that this material is an ionic protonic conductor at high temperature whereas the σac conductivity was indicative that the conduction mechanism is ensured by the correlated barrier hopping (CBH) model. The variation of M″ versus frequency proved to be a thermally activated dielectric relaxation process. Notably, we specified determined the direct optical band gap Eg = 2.3 eV in order to characterize the optical properties.

Detection of Lead and Environmental Parameters with Sulfur Film Modification of Screen Print Electrode

Environmental electrochemical sensors are an exciting field with a high volume of possibilities. Screen print electrodes have a tremendous advantage for environmental applications as they are 1) capable of performing laboratory and field measurements 2) allow a variety of surface science techniques and provide 3) an excellent outreach medium for students to learn about a variety of engineering and scientific disciplines. The use of redox-active (faradaic or “duck curve”) and non-redox (non-faradaic or capacitance) elements were used to detect lead and bicarbonate respectively using cyclic voltammetry. Aims of this project include the performance assessment of a screen print electrode with sulfur films treatments to detect these environmental compounds. This research education and outreach project summarizes efforts made to conduct and disseminate environmental electrochemistry to students in the New Brunswick area and Rutgers University. Remote and in-person learning labs were conducted to teach students fundamentals of electrochemistry and empower an underserved population to pursue science and engineering disciplines.

An Incremental Double Layer Capacitance of a Novel Ring-Disk Electrodes Array for Avidin/Strepavidin Sensing

Electric double layer (EDL) is established by ion redistribution at a solid-liquid interface. This ion redistribution electrically screens solid-surface charges and renders the interface to neutral. As a result, EDL is highly related to the surface potential, and a capacitor or constant phase element (CPE) is always employed to model the relationship between EDL and surface potential. According to this mechanism, diverse applications have been developed by controlling EDL via modulate potential fields or surface modifications. However, most of previous methods are sophisticated and hard to implemented as an in-situ monitoring method. To address this demand, we proposed a ring-disk electrode array (RDA) architecture to detect the changes of EDL capacitance between ring and disk electrode.Based on the proposed architecture, the surface potential will change while the biomolecular is immobilized onto to the vertical nanogap. This effect is verified by immobilizing different charged functional groups and the correlation between the surface potential and incremental-capacitance variance is also demonstrated. Based on this effect, the application for Avidin detection is implemented. The detectable range for Avidin measurement is from 100 fg/ml to 1 ng/ml.Based on this work, the incremental double-layer capacitance of a planar nanogap structure can provide a simple and reliable method for surface potential monitoring and can be used for different chemical and clinical examinations. Figure 1