Line Electrode Research Articles

Electrostatic precipitability of TiB2-Fe-Mo-Co ceramic-metal composites

TiB2 was used as the base body, and Fe, Mo, and Co metal powder particles were used as reinforcements to pressurize TiB2-Fe-Mo-Co ceramic–metal composites and resolve the heavy weight and unevenness of the traditional wet electrostatic precipitator (WESP) plate. The performance of its electrostatic precipitator was analyzed. Results revealed that the prepared ceramic–metal composites had a hardness of 95.6 HRA, a porosity of 4.01%, a density of 6050 kg/m3, and a conductivity of 3.90 × 106 S/m, the relative rot mean square values of the barbed electrode line and the fishbone discharge electrode line plate were 3.946 × 10−3 and 2.967 × 10−3. The powder was well polymerized, and the surface can form a considerable pore size. The overall compactness was good, which was beneficial for maintaining the mechanical strength of the product. The metal was wrapped well, which was conducive for the uniform distribution of the cleaning water. Compared with conventional WESP plate, the cermet plate had lower density and superior mechanical and electrical properties. The cermet plate addresses the overweightness of the traditional plate overweight and the uneven water distribution, making the former a promising alternative to the traditional WESP plate.

5926Electrically stimulating wide-areas of the epicardial surfaces of large mammalian ventricles is achievable with line electrodes

5926Electrically stimulating wide-areas of the epicardial surfaces of large mammalian ventricles is achievable with line electrodes

Optimized electrical resistivity tomography investigation established in identifying pit tombs of Mogareb, a cemetery area in a Pre-Aksumite archaeological site of Seglamen, northern Ethiopia

The larger area of Aksum is known as the most important archaeological areas in northern Ethiopia. It is included in the UNESCO World Heritage List as from about the IV century BC, it developed as one of several polities on the Tigrean plateau and emerged as the capital city of a powerful kingdom roughly between the II and the VIII centuries AD. The Mogareb is a cemetery in a Pre-Aksumite archaeological site of Seglamen located about 12 km South-West of Aksum.The geophysical survey was deployed to investigate the cemetery with the objective of finding and locating unmarked tombs. This work was also intended to test potential of the technique for the wider archaeological area of Aksum, in similar context to Mogareb, where application of geophysical techniques in multidisciplinary archaeological researches, in general, is not common.The approach in this work established an optimized use of the electrical resistivity tomography technique in understanding the archaeological context of the Pre-Aksumite site of Seglamen. The electrical resistivity tomography investigation of large cemetery sites as Mogareb requires a methodological approach designed to define areas of maximum interest where data collection should be planned. Thus, the ERT method suited the Mogareb cemetery area due to the large amount of apriory information from previous archaeological expeditions involving surface collections and excavations that identified and limit extent of the cemetery and were used in the calibration of geophysical survey results.The electrical resistivity tomography survey was conducted on a rectangular grid of 19.5 m by 44.25 m with 0.75 m unit electrode spacing and line spacing in a Dipole-Dipole configuration resulting in high resolvable 2D and 3D electrical resistivity model sections. The models were successful to show interpreted pit tombs anomalies some of which were verified in an excavation of a 10 m by 10 m grid that had an overlap of 6 m by 10 m area to the Northern edge of the electrical resistivity tomography grid.

Fault-Tolerant Sensor Detection of sEMG signals: Quality Analysis Using a Two-Class Support Vector Machine.

The capacity to identify the contamination in surface electromyography (sEMG) signals is necessary for applying the sEMG controlled prosthesis over time. In this paper, the method for the automatic identification of commonly occurring contaminant types in sEMG signals is evaluated. The presented approach uses two-class support vector machine (SVM) trained with clean sEMG and artificially contaminated sEMG. The contaminants considered include electrocardiogram interference, motion artefact, power line interference, amplifier saturation, and electrode displacement. The results demonstrated that the sEMG signal with the contaminants could readily be distinguished, even with increase channels degraded. The SFTD detection depends on the noise type, whether the amputee or non-amputee subjects and which channel is being analysed. This method presented a suitable solution for the detection of contaminants in the sEMG signal, being able to provide the acquired signal validation before the movement intended recognition to operate in an intelligent recognition with greater reliability.

Triboelectrification-enabled thin-film tactile matrix for self-powered high-resolution imaging

Tactile sensors have broad applications in human-machine interfacing technologies. In this work, we report a type of a thin-film-based flexible integrated triboelectric sensing matrix (ITESM) that is of high resolution and large area. It has a total of 3600 sensing units and a resolution of 50 dots per inch (dpi), which are 14 times and 25 times of the state-of-the-art works on the triboelectric sensor array, respectively. When touched by an external object, the ITESM generates a voltage signal in its bit electrode lines and word electrode lines due to the combination of triboelectrification and electrostatic induction. With the assistance of a signal processing circuit that filters and amplifies the electric signal, an average voltage signal of 0.4 V can be acquired. Due to the design of a shielding layer, the electrostatic induction among adjacent electrode lines are effectively eliminated, resulting in a near end crosstalk (NEXT) of merely 0.05. As a result, single-point as well as multi-point contacts can be explicitly revealed. Therefore, the ITESM in this work presents a major step in the direction of high-resolution and large-area triboelectric sensing.

Electrical Field Guided Electrospray Deposition for Production of Gradient Particle Patterns.

Our previous work demonstrated the uniform particle pattern formation on the substrates using electrical field guided electrospray deposition. In this work, we reported for the first time the fabrication of gradient particle patterns on glass slides using an additional point, line, or bar electrode based on our previous electrospray deposition configuration. We also demonstrated that the polydimethylsiloxane (PDMS) coating could result in the formation of uniform particle patterns instead of gradient particle patterns on glass slides using the same experimental setup. Meanwhile, we investigated the effect of experimental configurations on the gradient particle pattern formation by computational simulation. The simulation results are in line with experimental observations. The formation of gradient particle patterns was ascribed to the gradient of electric field and the corresponding focusing effect. Cell patterns can be formed on the particle patterns deposited on PDMS-coated glass slides. The formed particle patterns hold great promise for high-throughput screening of biomaterial-cell interactions and sensing.

The detailed characteristics of positive corona current pulses in the line-to-plane electrodes

The corona current pulses generated by corona discharge are the sources of the radio interference from transmission lines and the detailed characteristics of the corona current pulses from conductor should be investigated in order to reveal their generation mechanism. In this paper, the line-to-plane electrodes are designed to measure and analyze the characteristics of corona current pulses from positive corona discharges. The influences of inter-electrode gap and line diameters on the detail characteristics of corona current pulses, such as pulse amplitude, rise time, duration time and repetition frequency, are carefully analyzed. The obtained results show that the pulse amplitude and the repetition frequency increase with the diameter of line electrode when the electric fields on the surface of line electrodes are same. With the increase of inter-electrode gap, the pulse amplitude and the repetition frequency first decrease and then turn to be stable, while the rise time first increases and finally turns to be stable. The distributions of electric field and space charges under the line electrodes are calculated, and the influences of inter-electrode gap and line electrode diameter on the experimental results are qualitatively explained.

Investigation of the line arrangement of 2D resistivity surveys for 3D inversion

We have conducted numerical and field experiments to investigate the applicability of electrode configurations and line layouts commonly used for two-dimensional (2D) resistivity surveys to 3D inversion. We examined three kinds of electrode configurations and two types of line arrangements, for 16 resistivity models of a conductive body in a homogeneous half-space. The results of the numerical experiment revealed that the parallel-line arrangement was effective in identifying the approximate location of the conductive body. The orthogonal-line arrangement was optimal for identifying a target body near the line intersection. As a result, we propose that parallel lines are useful to highlight areas of particular interest where further detailed work with an intersecting line could be carried out. In the field experiment, 2D resistivity data were measured on a loam layer with a backfilled pit. The reconstructed resistivity image derived from parallel-line data showed a low-resistivity portion near the backfilled pit. When an orthogonal line was added to the parallel lines, the newly estimated location of the backfilled pit coincided well with the actual location. In a further field application, we collected several 2D resistivity datasets in the Nojima Fault area in Awaji Island. The 3D inversion of these datasets provided a resistivity distribution corresponding to the geological structure. In particular, the Nojima Fault was imaged as the western boundary of a low-resistivity belt, from only two orthogonal lines.

Insulation Coordination of Arcing Horns on HVDC Electrode Lines: Protection Performance Evaluation, Influence Factors and Improvement Method

Arcing horns are widely used in high voltage overhead lines to protect insulator strings from being destroyed by the free burning arcs caused by lightening faults. In this paper, we focus on the insulation coordination of arcing horns on the electrode lines of a 5000 MW, ±800 kV high voltage direct current (HVDC) system. The protection performance of arcing horns are determined by the characteristics of not only the external system but also the fault arc. Therefore, the behaviors and characteristics of long free burning arcs are investigated by the experiments at first. In order to evaluate the protection performance of arcing horns, the static stability criterion U-I characteristic method is introduced. The influence factors on the protection performance of arcing horns are analyzed theoretically. Finally, the improvement methods for the protection performance of arcing horns are proposed, and the diversified configuration strategy of arcing horns is recommended for cost saving.

Relationship between Deterioration of Epoxy Resin and Change of Space Charge Distribution under Nonuniform Electric Field

SUMMARYReliability in the insulating materials is necessary in order to supply stable power. However, the nonuniform electric field is caused by foreign matters or voids in the insulating material. The deterioration of insulating material is accelerated due to the nonuniform electric field and it finally leads to a dielectric breakdown. It is likely that the space charge distribution is related to the deterioration of the insulating material. The pulsed electroacoustic method can make it possible to detect the space charge distribution and to get the valuable information for the deterioration diagnosis. In this study, a line‐plate electrodes system was used to bring nonuniform electric field and the epoxy resin was inserted as the insulating material between the line electrode and the plate electrode. The changes of space charge distribution were observed under nonuniform electric field before the dielectric breakdown. As a result, this study indicates that the charge is injected from the line electrode and the space charge distribution changes due to the deterioration of the epoxy resin.

The impact of cardiac tissue anisotropy on spiral wave superseding: A simulation study using ionic cell models

Several types of dangerous cardiac arrhythmias, such as paroxysmal tachycardia and fibrillation, are linked with the spiral waves of electrical excitation in the heart muscle. In many cases, these diseases must be cured immediately after their diagnosis. Low-voltage defibrillation and cardioversion are modern treatment methods. Electrotherapy is based on spiral wave superseding by a high-frequency pacing from an electrode. In the present work, we study the influence of the anisotropic myocardial structure and cell-level model on cardioversion results. We use long line and point electrodes. Intervals of effective stimulation periods are determined and compared for two ionic cell-level models. Of all the considered factors, the cell-level model appears to play the greatest role in the results.

Modeling of Structure Effect for Ferroelectric Capacitor Based on Poly(vinylidene fluoride-trifluoroethylene) Ultrathin Films.

The characteristics of ferroelectric capacitors with poly(vinylidene fluoride-trifluoroethlene) (P(VDF-TrFE)) films have been studied at different structures of cell electrodes. It is suggested that the effect of electrode structures could induce changes of performance. Remarkably, cells with line electrodes display a better polarization and fatigue resistance than those with flat electrodes. For P(VDF-TrFE) ultrathin films with different electrode structures, the models of charge compensation mechanism for depolarization field and domain fatigue decomposition are used to explain the effect of electrode structure. Furthermore, the driving voltage based on normal speed-functionality is designed, and the testing results show that the line electrode structure could induce a robust switching, which is determined by the free charges concentration in active layer. These findings provide an effective route to design the optimum structure for a ferroelectric capacitor based on P(VDF-TrFE) copolymer ultrathin film.

A facile approach for reducing the working voltage of Au/TiO2/Au nanostructured memristors by enhancing the local electric field

Memristor devices have attracted tremendous interest due to different applications ranging from nonvolatile data storage to neuromorphic computing units. Exploring the role of surface roughness of the bottom electrode (BE)/active layer interface provides useful guidelines for the optimization of the memristor switching performance. This study focuses on the effect of surface roughness of the BE electrode on the switching characteristics of Au/TiO2/Au three-layer memristor devices. An optimized wet-etching treatment condition was found to modify the surface roughness of the Au BE where the measurement results indicate that the roughness of the Au BE is affected by both duration time and solution concentrations of the wet-etching process. Then we fabricated arrays of TiO2-based nanostructured memristors sandwiched between two sets of cross-bar Au electrode lines (junction area 900 μm2). The results revealed a reduction in the working voltages in current–voltage characteristic of the device performance when increasing the surface roughness at the Au(BE)/TiO2 active layer interface. The set voltage of the device (Vset) significantly decreased from 2.26–1.93 V when we increased the interface roughness from 4.2–13.1 nm. The present work provides information for better understanding the switching mechanism of titanium-dioxide-based devices, and it can be inferred that enhancing the roughness of the Au BE/TiO2 active layer interface leads to a localized non-uniform electric field distribution that plays a vital role in reducing the energy consumption of the device.

Calculation Method and Influencing Factors of Overvoltage on Ground Electrode Line on Sending End Caused by Monopolar Fault in UHVDC Transmission System

Calculation Method and Influencing Factors of Overvoltage on Ground Electrode Line on Sending End Caused by Monopolar Fault in UHVDC Transmission System

Investigations on effects of the hole size to fix electrodes and interconnection lines in polydimethylsiloxane

Translational research in bioelectronics medicine and neural implants often relies on established material assemblies made of silicone rubber (polydimethylsiloxane-PDMS) and precious metals. Longevity of the compound is of utmost importance for implantable devices in therapeutic and rehabilitation applications. Therefore, secure mechanical fixation can be used in addition to chemical bonding mechanisms to interlock PDMS substrate and insulation layers with metal sheets for interconnection lines and electrodes. One of the best ways to fix metal lines and electrodes in PDMS is to design holes in electrode rims to allow for direct interconnection between top to bottom layer silicone. Hence, the best layouts and sizes of holes (up to 6) which provide sufficient stability against lateral and vertical forces have been investigated with a variety of numbers of hole in line electrodes, which are simulated and fabricated with different layouts, sizes and materials. Best stability was obtained with radii of 100, 72 and 62 µm, respectively, and a single central hole in aluminum, platinum and MP35N foil line electrodes of 400 × 500 µm2 size and of thickness 20 µm. The study showed that the best hole size which provides line electrode immobility (of thickness less than 30 µm) within a central hole is proportional to reverse value of Young’s Modulus of the material used. Thus, an array of line electrodes was designed and fabricated to study this effect. Experimental results were compared with simulation data. Subsequently, an approximation curve was generated as design rule to propose the best radius to fix line electrodes according to the material thickness between 10 and 200 µm using PDMS as substrate material.

PaCER - A fully automated method for electrode trajectory and contact reconstruction in deep brain stimulation.

Deep brain stimulation (DBS) is a neurosurgical intervention where electrodes are permanently implanted into the brain in order to modulate pathologic neural activity. The post-operative reconstruction of the DBS electrodes is important for an efficient stimulation parameter tuning. A major limitation of existing approaches for electrode reconstruction from post-operative imaging that prevents the clinical routine use is that they are manual or semi-automatic, and thus both time-consuming and subjective. Moreover, the existing methods rely on a simplified model of a straight line electrode trajectory, rather than the more realistic curved trajectory. The main contribution of this paper is that for the first time we present a highly accurate and fully automated method for electrode reconstruction that considers curved trajectories. The robustness of our proposed method is demonstrated using a multi-center clinical dataset consisting of N = 44 electrodes. In all cases the electrode trajectories were successfully identified and reconstructed. In addition, the accuracy is demonstrated quantitatively using a high-accuracy phantom with known ground truth. In the phantom experiment, the method could detect individual electrode contacts with high accuracy and the trajectory reconstruction reached an error level below 100 μm (0.046 ± 0.025 mm). An implementation of the method is made publicly available such that it can directly be used by researchers or clinicians. This constitutes an important step towards future integration of lead reconstruction into standard clinical care.

Triboelectrification-enabled touch sensing for self-powered position mapping and dynamic tracking by a flexible and area-scalable sensor array

A touch sensor is essentially a transducer that transforms physical touches into measurable electric signals. Here, we report a fabric-based self-powered triboelectric sensor array. Individual sensing units are constituted by intersections between row electrode lines and column electrode lines that have complementary patterns. When a sensing unit is touched, surface triboelectrification coupled with electrostatic induction generates an output voltage as high as ~25V on both the row and column electrode lines. Through proper shielding design, exceptionally low crosstalk between adjacent electrode lines is achieved, which gives an optimal near end crosstalk (NEXT) value of 0.01. A prototype of a visualized sensing system is demonstrated, which can display the position, the trajectory and the approximate profile of multiple contact objects in real time. The ITESA presented in this work does not rely on power supplies and possesses great flexibility as well as robustness. It can be scaled in area and is expected to be used in fields such as robotics, security monitoring, industrial automation, artificial intelligence, and health monitoring.

3D assessment of an underground mine pillar by combination of photogrammetric and geoelectric methods

The monitoring of underground cavities plays a key role in risk management policies. Mine and underground quarry stakeholders require relevant methodologies and practices to define and assess hazards associated with these structures. To monitor these structures, geophysical methods may offer an interesting compromise among operating cost, invasiveness, and risk assessment reliability. The use of conventional 3D-electric resistivity imaging (ERI) software validated on relatively flat media is not sufficient to efficiently assess complex 3D geometries such as underground mine pillars. We have developed a new approach to evaluate pillar condition by means of a sequential use of two techniques. First, the photogrammetric method yields a detailed 3D model of the pillar geometry from a set of pictures. Second, 3D-ERI is performed based on this suitable geometry. The methodology is tested on a synthetic model to evaluate the effect of various geometry resolutions on the inversion. We also evaluated the combination of the effect of measurement and geometry error. We performed a quasi 3D-ERI survey (three parallel electrode lines) on a real limestone mine pillar to determine the benefits and limitations of the combined procedure. First results revealed the capacity of the photogrammetric methods to obtain a high-precision geometry and its key role during the inversion process. Second results of the real case study revealed that a highly accurate geometry is required to detect accurately conductive anomalies in a complex 3D context.

Stretchable, Transparent, and Stretch-Unresponsive Capacitive Touch Sensor Array with Selectively Patterned Silver Nanowires/Reduced Graphene Oxide Electrodes.

Stretchable and transparent touch sensors are essential input devices for future stretchable transparent electronics. Capacitive touch sensors with a simple structure of only two electrodes and one dielectric are an established technology in current rigid electronics. However, the development of stretchable and transparent capacitive touch sensors has been limited due to changes in capacitance resulting from dimensional changes in elastomeric dielectrics and difficulty in obtaining stretchable transparent electrodes that are stable under large strains. Herein, a stretch-unresponsive stretchable and transparent capacitive touch sensor array was demonstrated by employing stretchable and transparent electrodes with a simple selective-patterning process and by carefully selecting dielectric and substrate materials with low strain responsivity. A selective-patterning process was used to embed a stretchable and transparent silver nanowires/reduced graphene oxide (AgNWs/rGO) electrode line into a polyurethane (PU) dielectric layer on a polydimethylsiloxane (PDMS) substrate using oxygen plasma treatment. This method provides the ability to directly fabricate thin film electrode lines on elastomeric substrates and can be used in conventional processes employed in stretchable electronics. We used a dielectric (PU) with a Poisson's ratio smaller than that of the substrate (PDMS), which prevented changes in the capacitance resulting from stretching of the sensor. The stretch-unresponsive touch sensing capability of our transparent and stretchable capacitive touch sensor has great potential in wearable electronics and human-machine interfaces.

Fabrication of ultrathin TiO2 film with nanogrooves to trap organic dye nanoparticles

Ultrathin TiO2 films were formed on the surface of commercially available DVD-R disks by a two-step sol–gel process, with nanogrooves on the lower surface transcribed from the DVD-R disk surface. Water suspension of organic dye nanoparticles (NPs) fabricated by laser processing of dye solution was spread over the TiO2 film, attaining a successful trap of luminescent dye NPs inside the transcribed nanogrooves, which will open up a new way of luminescent NP deposition with a predesigned pattern, in view of printing mass production of static image “digital signage devices.” For this application, all the NPs need to be placed between and in contact with two line electrodes. As a test pattern, we have tried to deposit silver nanowires (AgNWs) in parallel arrangement in the nanogrooves of TiO2 film by the doctor blade method.