Plate Electrodes Research Articles

Parameter characterization of variable bending stiffness module with electrostatic layer jamming based on giant electrorheological fluid

Soft grippers exhibit good adaptability, but their grasping performance is limited. Variable-stiffness technology has been applied to soft grippers to address this problem. Therefore, a variable bending stiffness module (VBSM) with electrostatic layer jamming based on a giant electrorheological fluid (ELJ-GERF) for soft robots is proposed in this study, which exhibits a faster response time and a wider range of stiffness variation. A VBSM prototype is fabricated, and a theoretical model is established. The stiffness is mainly affected by the electrode quantity, overlapping area of electrode plates, insulator and conductive layers’ thickness, medium thickness and the exciting voltage. Direct current (DC) voltage experiments and alternating current (AC) voltage experiments were conducted on the test samples of filled with air (ELJ-AIR), silicone oil (ELJ-OIL), and ELJ-GERF. The experimental result show that stiffness-regulation of the VBSM can be achieved by adjusting the exciting voltage, and AC voltage being more suitable for regulating the stiffness of the VBSM than DC voltage. For AC voltage, the stiffness of ELJ-GERF increases to 53.5 times when a 4 kV voltage is applied. The stiffness variation range is about 2 to 3 times greater than that of ELJ-AIR or ELJ-OIL. Through the stiffness characterization experiment, the stiffness of the VBSM in this study is influenced by the viscosity of the GERF and the gap between the electrode plates. Through the capacitance test, the VBSM exhibits self-sensing ability. Finally, the VBSM is applied to a soft gripper, the vibration performance and variable stiffness performance in its application are verified.

Study on the performance of biochar prepared from walnut shell and traditional graphene electrode plate in the treatment of domestic sewage in microbial fuel cells.

As a new pollutant treatment technology, microbial fuel cell (MFC) has a broad prospect. In this article, the devices assembled using walnut shells are named biochar-microbial fuel cell (B-MFC), and the devices assembled using graphene are named graphene-microbial fuel cell (G-MFC). Under the condition of an external resistance of 1,000 Ω, the B-MFC with biochar as the electrode plate can generate a voltage of up to 75.26 mV. The maximum power density is 76.61 mW/m2, and the total internal resistance is 3,117.09 Ω. The removal efficiency of B-MFC for ammonia nitrogen (NH3-N), chemical oxygen demand (COD), total nitrogen (TN), and total phosphorus (TP) was higher than that of G-MFC. The results of microbial analysis showed that there was more operational taxonomic unit (OTU) on the walnut shell biochar electrode plate. The final analysis of the two electrode materials using BET specific surface area testing method (BET) and scanning electron microscope (SEM) showed that the pore size of walnut shell biochar was smaller, the specific surface area was larger, and the pore distribution was smoother. The results show that using walnut shells to make electrode plates is an optional waste recycling method and an electrode plate with excellent development prospects.

Fractal growth of copper powder on point and plate electrodes based on diffusion-limited aggregation model

Fractal growth of copper powder on point and plate electrodes based on diffusion-limited aggregation model

Experimental study on enhancing electrostatic charging of nonwoven filter media through novel electrode configurations

The COVID-19 pandemic has underscored the urgent need for efficient particle filtration to tackle public health challenges. This study compares the electrostatic charging capabilities of two types of electrodes: conventional Metal Lamellar Electrodes (MLE) and Modified Lamellar Plate Electrodes (MLPE) with PMMA insulation, in their role of charging nonwoven polypropylene filter media. Experimental analysis unequivocally demonstrates the superiority of MLPE in promoting effective electrostatic charge, as influenced by applied high voltage and inter-electrode distance, resulting in a significant enhancement in fine particle filtration. Numerical simulations of the electric field conducted using the COMSOL software and employing the Finite Element Method (FEM) validate these findings. FEM discretizes the domain into small finite elements and applies Laplace's equation in charge-free regions, providing a comprehensive understanding of the behavior of dual-electrode corona discharge systems. These simulations indicate higher field intensities for MLPE compared to MLE.By integrating experimental and numerical analyses, this study sheds light on the potential benefits of MLPE for air filtration systems, offering a noteworthy advancement in the control of airborne infections and reduction of environmental health risks. This research lays the groundwork for the development of more efficient and durable filtration systems, meeting the increasing demands for public health protection.The findings of this study suggest that the adoption of MLPE could significantly contribute to improving indoor air quality and mitigating the transmission of respiratory diseases. MLPE may also find utility in industrial filtration and air purification in sensitive work environments. Ultimately, this research sets the stage for the development of more efficient and sustainable filtration systems, addressing the growing needs for public health protection.

Effect analysis on recycling of cathode material from spent ternary lithium-ion batteries via supercritical water oxidation and acid-leaching

This study proposed a recycling method for spent batteries by combining supercritical water oxidation and acid-leaching. In supercritical water oxidation process, the cathode material was separated from the electrode plate, and 98% of lithium in the cathode was leached to achieve the separation of lithium from Ni, Co and Mn. Ni, Co and Mn were then leached during the acid leaching process. The effect of solid-liquid ratio, oxidant mass concentration, reaction time and temperature in supercritical process on metal leaching was analyzed. The leaching rate of Ni, Co and Mn was improved by increasing the mass concentration of oxidant and the reaction temperature. The effect of reaction time on metal leaching is related to the mass concentration of oxidant in the solution. Through the control of paraments, the leaching efficiencies of Ni, Co and Mn were significantly improved from 90.4%, 84.7%, 86.4–99.7%, 96.8% and 98.5%.

Impact of Reduced Activity on Endurance of Rat Diaphragm Muscle

The diaphragm muscle (DIAm) as the major inspiratory pump is highly active. During breathing, fatigue resistant DIAm motor units are recruited that comprise type I and IIa fibers. Accordingly, these fibers have substantially higher mitochondrial volume density (MVD) and mitochondrial respiratory capacity (SDHmax) compared to more fatigable type IIx/IIb fibers. Cervical spinal cord injury disrupts descending inspiratory drive and markedly reduces eupneic activity of the DIAm. With C2 spinal cord hemisection (C2SH) DIAm activity on the ipsilateral side is reduced. Following a two-week period of C2SH, we found reduced MVD and SDHmax in type I and IIa DIAm fibers. As a result, we hypothesize that endurance of the DIAm is reduced. Female and male Sprague Dawley rats were used. EMG electrodes were placed in the left and right DIAm 3 days prior to C2SH surgery, and baseline recordings of eupneic DIAm activity were obtained in awake animals. The right C2 spinal cord was hemisected, and the extent of injury was confirmed by the absence of eupneic DIAm activity on the ipsilateral side while animals were anesthetized. Subsequently, DIAm EMG activity was recorded at 3, 7 and 14 days post C2SH. After two weeks, rats were anesthetized and the DIAm was excised. DIAm strips were cut and suspended in a tissue chamber containing Rees-Simpson solution maintained at 26oC, with thecostal margin clamped and the central tendon attached to a Cambridge Dual-Mode force/length transducer. DIAm strips were stimulated using platinum plate electrodes with supramaximal current (~250 mA) pulses (1 ms), and maximum specific force was determined at 75 Hz. The force-velocity relationship was then determined by systematically changing load, and maximum velocity (Vmax) was estimated based on curve fitting with the Hill-equation. Based on the force-velocity measurements peak power of the DIAm was calculated. Subsequently, the DIAm was repetitively stimulated and allowed to shorten at 30% maximum velocity (isovelocity approximating peak power output). Endurance of the DIAm was then determined as the duration that peak power output was sustained. Finally, the DIAm was rapidly frozen, and cross-sections were cut for fiber type and cross-sectional area (CSA) measurements. C2SH resulted in a marked decrease in eupneic DIAm EMG activity across the two-week period, which disproportionately affected type I and IIa DIAm fibers. However, there was no impact of C2SH on DIAm fiber type proportions or CSA. Following two-weeks C2SH, maximum specific force, Vmax, and peak power output of the DIAm were comparable between intact and injured sides. However, endurance of the DIAm was reduced on the injured side compared to the intact side. These results support our hypothesis that reduced activity of DIAm, reduces oxidative capacity of type I and IIa fibers and thereby reduces endurance. In clinical conditions such as mechanical ventilation DIAm activity is reduced and if maintained for longer periods of time this may affect DIAm endurance post weaning. Research supported by NIH grant: HL146114 (GCS). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

KARAKTERISTIK TEGANGAN TEMBUS MINYAK TRAFO SHELL DIALA B MENGGUNAKAN MATERIAL ELEKTRODA BERBAHAN STAINLES STEEL, KUNINGAN, TEMBAGA DAN ALUMUNIUM

Transformer oil insulation breakdown voltage testing is usually carried out at high AC voltage using the SPLN 49-1 1982 standard. The electrodes used are hemispherical electrodes with a distance between the electrodes of 2.5mm. The breakdown voltage value of transformer oil insulation that meets the standards according to SPLN 49-1 of 1982 is 30 kV/2.5mm. In this research, a new Shell Diala B brand transformer oil insulation breakdown voltage test was carried out using the SPLN 49-1 1982 testing standard. The novelty of this research is using various electrode shapes and different electrode materials to test the breakdown voltage of the transformer oil's liquid insulation. The method used in this research is an experimental method where the test is adapted to the SPLN 49-1 standard of 1982. The electrodes used are ball, needle, and plate electrodes. Based on test results at a distance between electrodes of 2.5 mm, it was found that the breakdown voltage characteristics of stainless steel, brass, copper, and aluminum electrode materials varied and did not meet the SPLN 49-1 1982 standard, namely 30 kV/2.5 mm.

Treatment of electroplating wastewater using electrocoagulation and integrated membrane.

Electroplating wastewater contains heavy metal ions and organic matter. These contaminants not only endanger the environment but also pose risks to human health. Despite the development of various treatment processes such as chemical precipitation MBR, electrocoagulation (EC) ceramic membrane (CM), coagulation ultrafiltration (UF) reverse osmosis (RO), and CM RO. These methods are only effective for low concentrations of heavy metals and struggle with high concentrations. To address the challenge of treating electroplating wastewater with high heavy metal content, this study focuses on the wastewater from Dongfang Aviation Machinery Processing Plant. It introduces an EC and integrated membrane (IM) treatment process for electroplating wastewater. The IM comprises microfiltration (MF) membrane, nanofiltration (NF) membrane, and RO membrane. Results indicated that under specific conditions, such as a pH of 8, current density of 5 A/dm2, electrode plate spacing of 2 cm, 35 min of electrolysis time, and influent pH of 10 for the IM, removal rates of Zn2+, Cu2+, Ni2+, and TCr in the wastewater exceeded 99%. The removal rates of chemical oxygen demand (COD), suspended solids (SS), total phosphorus (TP), total nitrogen (TN), and petroleum in wastewater exceed 97%. Following a continuous cleaning process, the membrane flux can consistently recover to over 94.3%.

Vibration reduction and energy harvesting of the marine stern shaft-bearing systems with triboelectric generator

The stringent requirements for vibration reduction in marine propeller shaft are essential due to the increased effects of transverse vibration. In order to effectively minimize the energy consumption and realize the energy harvesting during the process of vibration control, a triboelectric generator is proposed for the marine stern bearing-shaft systems by a combination of vibration reduction and energy harvesting. The vibration reduction is achieved using an adjustable damping magnetorheological shock absorber. The energy harvesting is realized through contact electrification and electrostatic induction during the vertical contact-separation of electrode plate. The Poincaré surface of the shaft and bearing demonstrates that the proposed triboelectric generator can be applicable for the vibration reduction and energy harvesting. Meanwhile, the controlled responses of suspension travel, soleplate deflection, acceleration of shaft and bearing, and forces are subjected to analysis. The energy harvesting process encompasses the acquisition of resistor current, PDMS charge, open-circuit voltage and electrical energy of the system. Moreover, the influence of various model parameters on both vibration reduction rate and electrical energy harvesting are discussed. It is anticipated that a more optimal satisfaction in terms of vibration reduction and energy harvesting can be attained through the adjustment of model parameter.

PFAS degradation by anodic electrooxidation: Influence of BDD electrode configuration and presence of dissolved organic matter

Per- and poly-fluoroalkyl substances (PFAS) pose substantial environmental and human health risks. Electrochemical oxidation technology is a promising large-scale solution for PFAS degradation due to its simplicity and minimal waste generation. This study investigated the electrochemical performance of boron-doped diamond (BDD) electrodes in degrading PFAS using a recirculation cell with plate and mesh electrodes. The study found that increasing the current density from 6.4 mA/cm2 to 40 mA/cm2 resulted in a transition of the reaction rate from pseudo-first-order toward zero-order kinetics. The stepwise degradation mechanism and the formation of intermediate products were also explored. Carbon and fluorine molar balance analysis revealed that the missing intermediates do not contain fluoride atoms in their molecular formula. The shape and surface of the electrodes had a significant impact on their performance, in particular, improving the degradation of the most recalcitrant perfluorobutanoic acid. The influence of different fractions of dissolved organic matter (DOM) on perfluorohexanoic acid degradation shows that overall, DOM does not significantly inhibit its degradation. Some inhibition was observed in the presence of DOM enriched in carbohydrates, organics that are known to exert strong interaction properties with organic and inorganic surfaces. The synergistic effect of direct anodic oxidation and indirect degradation by reactive radical species enables the decomposition of both DOM and PFAS. Finally, high removal percentages of short (up to 96 %) and long-chain PFAS (up to 99 %) were obtained using BDD electrooxidation cells combining plate and mesh electrodes when treating reverse osmosis concentrate containing PFAS.

Effect of Electric field on Dielectric Loads by Using the Electrode Plates for Exterminating Pests Applications

Effect of Electric field on Dielectric Loads by Using the Electrode Plates for Exterminating Pests Applications

Ionic wind tweezer based on multi-needle corona discharge for programmable droplet manipulation

The manipulation and guidance of tiny droplets are crucial for advancements in fields such as microfluidics, biomedical research, and materials science. In this study, we achieve precise active control of lubricated surface liquid droplets through a multi-needle corona discharge ionic wind tweezer featuring programmed manipulation. The ionic wind tweezer continuously injects charge onto the surface of plate electrodes, causing the oil layer on the electrode surface to form a unique cross-shaped pattern. This pattern confines droplets within the central area of the needle tip, enabling the manipulation of droplets of different compositions, volumes, and arrays. In addition to manipulating water droplets, ionic wind tweezers can also control various solid or liquid particles, revealing the wide applicability and operational capabilities of this method. This work not only provides a flexible strategy for precise droplet manipulation but also sheds light on the application of microfluidics technology in droplet chemical reactions.

A new ER valve composed of multilayer mesh electrodes

In many cases, ER valves are required to be used at lower operating voltages. For example, to develop a two-dimensional Braille matrix display, it is necessary to lay out many ER valves and control each Braille dot independently. If the commonly used parallel plate electrodes are applied, a low voltage can only be used when the electrode gap is very small, which will make the ER valve flow resistance very large, thus making it difficult to achieve effective control. A new type of ER valve composed of multilayer mesh electrodes was designed, which are arranged vertically in the direction of ER fluid flow. The flow rate of the ER valve is determined by the opening ratio of the mesh electrodes. This type of mesh electrode results in a more complex electric field distribution, which has a different action pattern on ER fluid yield stress compared to parallel electrodes. The non-uniform electric field generated by mesh electrodes under different operating voltages was simulated using COMSOL software, and the pressure drops of ER valves with various sizes of mesh electrodes under different voltages were experimentally investigated. The results indicate that the longitudinal electric field component plays a dominant role, and the stress of the ER fluid exhibits a periodic and gradient distribution. This valve exhibits good ER performance when the applied voltage is much lower than that of parallel electrodes. At the same time, the flow rate of the ER valve can be increased by enlarging the opening ratio of the mesh electrodes. Even if the applied voltage is 180 V, the pressure drop of the ER valve is large enough and the operation stability is good. This new type of ER valve makes the device small in size, easy to control intelligently and low cost. Multilayer mesh electrodes also have universal application value in ER technology.

Accurate low-energy pulse system for intravascular lithotripsy

In response to biomedical imperatives, a novel approach is presented for the endovascular management of atherosclerosis. This approach is grounded in the electrohydraulic effect of a precisely controlled low-energy pulse discharge system, coupled with sequential control within the incomplete discharge electrode, to generate shockwaves aimed at softening blood vessels and rupturing calcified plaques. Theoretical analysis encompassed circuit design, control timing, and operational processes, while experimental investigations demonstrated precise control of non-oscillation and incomplete discharge by adjusting key parameters. Utilizing a 3 kV DC high-voltage power supply, a 220 nF capacitor, and two sets of 3.3 Ω resistors in parallel, with pin–plate electrodes as the load for discharge in normal saline, resulted in a 1 kV reduction in voltage across the capacitor and a peak current of 170 A. Energy release occurred through non-oscillatory and incomplete discharge, effectively generating shockwaves with peak pressures of 5–10 MPa at distances of 1–2 mm from the discharge center to treat calcified lesions. Compared with the existing intravascular lithotripsy devices, the shockwave system realizes accurate control of discharge energy by adjusting the turn-off time of incomplete discharge so as to realize accurate control of shockwave energy. Doctors can choose different intensities of shockwaves according to different degrees of calcification in the treatment process so as to minimize the discomfort caused by shockwaves and improve safety. Valuable insights are provided for intravascular lithotripsy devices in engineering.

Characterization of electric field distribution in valve-side casing of 500 kV converter transformer considering AC and DC mixed voltage

The converter transformer, as one of the indispensable core devices in the ultra-high voltage direct current (UHVDC) transmission system, exhibits highly complex electric field distribution characteristics within the valve-side bushing. In-depth research into the electric field distribution characteristics and variation patterns of the valve-side bushing under both alternating current (AC) and direct current (DC) voltage conditions is crucial for ensuring the reliable operation of the transmission system. This study focuses on investigating the electric field distribution of the valve-side bushing under AC and DC voltage excitations. A full-scale finite element model of the valve-side bushing of the converter transformer is constructed using finite element simulation software for modeling and research purposes. The results indicate that the internal electric field distribution of the bushing is generally similar under both AC and DC voltage excitations. However, in the SF6-filled region, a steeper voltage drop is observed under DC excitation compared to AC. The space charges generated in the DC electric field due to field polarization have a significant impact on the distortion of the electric field on the inner and outermost layer electrode plates. These conclusions provide theoretical guidance for the insulation design of the valve-side bushing in converter transformers at the 500 kV voltage level and similar ratings.

Spatially resolved measurement of the electrostatic charge of turbulent powder flows

This article reports on measurements of the electrostatic charge of particles in a turbulent duct flow. In contrast to previous charge measurements, which do not apply to turbulent flows or give only the sum of all particles’ charges, the new method resolves the charge of a turbulent powder flow spatially. The experiment consists of a particle tracking velocimetry (PTV) system and electrode plates that generate an electric field. By comparing particle velocities and accelerations with and without the electric field, the time-averaged local particle charge profile is derived. Spatially resolving the charge profiles unveiled bipolar particle flow. The average of the charge profiles agreed well with a conventional Faraday pail measurement, demonstrating the accuracy of our measurements. However, the peak value of the charge profiles was 76 times higher than the average of the particles’ charge.

Sensitive electrochemical flow injection analysis of H2O2 released from cells with a pass-through mode

Conventional plate electrodes were commonly used in electrochemical flow injection analysis and only part of molecules diffused to the plane of electrodes could be detected, which would limit the performance of electrochemical detection. In this study, a low-cost native stainless steel wire mesh (SSWM) electrode was integrated into a 3D-printed device for electrochemical flow injection analysis with a pass-through mode, which is different compared with previous flow-through mode. This strategy was applied for sensitive analysis of hydrogen peroxide (H2O2) released from cells. Under the optimal conditions (the applied potentials, the flow rate and the sample volume), the device exhibits high sensitivity toward H2O2. Linear relationships could be achieved between electrochemical responses and the concentration of H2O2 ranging from 1 nM to 1 mM. The excellent analytical performance of the SSWM-based device could be attributed to the pass-through mode based on the mesh microstructure and intrinsic catalytic properties for H2O2 by stainless steel. This approach could be further successfully extended for screening of H2O2 released from HeLa cells with electrochemical responses linear to the number of cells in a range of 3 - 1.35 × 104 cells with an injection volume of 30 μL. This study revealed the potential of mesh electrodes in electrochemical flow injection analysis for cellular function and pathology and its possible extension in cell counting and on-line analysis.

Separation of oil–water emulsions by electrocoagulation and electro-persulfate with sonication pretreatment: Determination of economical electrode configuration, optimization, and comparison

This study aimed to separate oil–water emulsions by electrocoagulation (EC), which is considered an effective and promising method for sustainable water management, and the electro-persulfate method (EPS) as an advanced EC process. Firstly, oil–water emulsions were treated with EC using three different electrode configurations and the most economical electrode pair (perforated and plate electrodes) was determined. Secondly, the Box-Behnken design (BBD) was applied to explore the influence of operational variables (pH, current density, and electrolysis time for EC; pH, current density, PS/COD, and electrolysis time for EPS) on the removal of COD (5800 mg/L) as a response with the identified electrodes. As a result, at neutral pH, the optimal operating conditions determined for maximum COD removal were 27 mA/cm2 and 37 min for EC and 27 mA/cm2, 25 min, and PS/COD = 0.5 for EPS. At the predicted optimal conditions, the predicted and tested COD removal was respectively 100 % and 97.15 % for EC, 88.18 % and 87.94 % for EPS. Moreover, the total cost was 2.39 $/m3 and 1.27 $/m3 for EC and EPS, respectively. Consequently, it was determined that perforated electrodes were more economical, and EC achieved higher wastewater treatment performance than EPS, however, from an economic point of view, the EPS process enabled the more efficient treatment of oil–water emulsions.

Giant vesicles form in physiological saline and encapsulate pDNA by the modified electroformation method

Giant vesicles (GVs) are used to study the structures and functions of cells and cell membranes. Electroformation is the most commonly used method for GV preparation. However, the electroformation of GVs is hindered in highly concentrated ionic solutions, limiting their application as cell models for research under physiological conditions. In this study, giant multilayer vesicles were successfully generated in physiological saline using a modified electroformation device by adding an insulating layer between the two electrode plates. The influence of the electric frequency and strength on the electroformation of GVs in physiological saline was explored, and a possible mechanism for this improvement was assessed. It has been shown that an insulating layer between the two electrodes can improve the electroformation of GVs in physiological saline by increasing the electrical impedance, which is weakened by the saline solution, thereby restoring the reduced effective electric field strength. Furthermore, macromolecular plasmid DNA (pDNA) was successfully encapsulated in the electroformed GVs of the modified device. This modified electroformation method may be useful for generating eukaryotic cell models under physiological conditions.

Ion migration mechanism of electrochemical water softening in dual-chamber reactors and their performance for real circulating cooling water

Electrochemical water softening studies often use ion exchange membrane (IEM) reactors. However, their practical application is limited because of inevitable cathodic scaling. To overcome this challenge, one necessary approach is to understand the ion migration mechanism in the typical IEM reactor. In this study, we used operando visualization to reveal that the divider such as IEM or nylon nets was essential to confine the neutralization reaction between H+ and OH−. Ca2+ and Mg2+ may transfer from the anode chamber through the divider into the cathode chamber via electromigration. Using mesh electrodes instead of plate electrodes, the total hardness removal in the cathode chamber and anode chamber was 94.2% and 92.5%, respectively. The high removal rate was attributed to H2 microbubbles produced by cathodic water electrolysis, which drove OH− ions diffusion into solution and sequentially strengthened the nucleation of scale crystals in solution rather than on the cathode surface. On the basis of the above ion migration mechanism, the revolutionized reactor with mesh electrode module and nylon-net divider exhibited good performance in softening real circulating cooling water, and the total hardness removal exceeded 93.1% during 30 h running. These results open new horizons for improving the practicability of electrochemical water softening.