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This paper investigates the measurement of fat-free mass (FFM) by bioimpedance using foot-to-foot impedancemeters (FFI) with plantar electrodes measuring the foot-to-foot resistance R34 and hand-to-foot medical impedancemeters. FFM measurements were compared with corresponding data using Dual X-ray absorptiometry (DXA). Equations giving FFM were established using linear multiple regression on DXA data in a first group of 170 subjects. For validation, these equations were used on a second group of 86 subjects, and FFM were compared with DXA data; no significant difference was observed. The same protocol was repeated, but using electrodes on the right hand and foot in standing position to measure the hand to-foot resistance R13. Mean differences with DXA were higher for R13 than for R34. Effect of electrode size and feet position on resistance was also investigated. R34 decreased when electrode area increased or if feet were moved forward. It decreased if feet were moved backward. A proper configuration of contact electrodes can improve measurement accuracy and reproducibility of FFI.

Electrochemical CO2 reduction reaction (CO2RR) coupled with renewable electricity holds promises for efficient mitigation of carbon emission impacts on the environment and turning CO2 into valuable chemicals. One important task in CO2RR development is the design and fabrication of efficient electrodes for stable operation in the long term. Gas‐diffusion electrodes (GDEs) have been employed to continuously feed CO2 to the electrolyzers. Despite significant advances in GDE design and tailoring GDE properties, the present GDEs often suffer from the critical issue of flooding due to the electrowetting of carbon‐based substrates, which hinders the transition to industrial application. To address flooding, GDEs with intrinsically hydrophobic polymeric substrates have been recently fabricated and have shown promising performances. Herein, the advances and challenges associated with carbon‐free GDEs are reviewed for CO2RR. This review first briefly outlines GDE and electrolyzers basics. Through critical discussion around the shortcomings of conventional carbon‐based GDEs, the most recent efforts to resolve flooding are summarized. Subsequently, the advances, advantages, and challenges of carbon‐free GDEs are elaborated. Finally, priorities for future studies are suggested, with the aim to support the advancement and scale‐up of carbon‐free GDEs and extend them to other electrochemical systems where gas and the electrolyte are in contact. [ABSTRACT FROM AUTHOR]

Aqueous potassium‐ion batteries (AKIBs) with mild aqueous electrolytes can significantly mitigate the safety and environmental issues raised from traditional nonaqueous batteries, positioning them as promising candidates for grid‐scale applications. Nonetheless, the progression of AKIBs is currently impeded by the insufficient energy density, largely attributed to the limited voltage window of aqueous electrolytes. This review aims to introduce foundational knowledge about aqueous batteries, illustrates recent advancements in AKIBs, and offers valuable perspectives on designing electrode materials and optimizing electrolytes. To provide a systematic overview, the focus is on the following seven key sections: i) development history, ii) electrode materials, iii) electrolyte design, iv) current collectors, v) aqueous interphase chemistry, vi) full cell configurations, and vii) future prospects. Finally, constructive insights and suggestions are provided for the development of AKIBs with higher energy density. [ABSTRACT FROM AUTHOR]

Current liquid crystal (LC) lenses cannot achieve lossless arbitrary movement of the optical axis without mechanical movement. This article designs a novel bottom electrode through simulation and optimization, which forms a special LC lens with an Archimedean spiral electrode, realizing a 3D LC wedge and an arbitrarily movable LC lens. When only the bottom electrode is controlled, it achieves a maximum beam steering angle of 0.164°, which is nearly an order of magnitude larger than the current design. When the top and bottom electrodes are controlled jointly, a 0.164° movement of the lens optical axis is achieved. With focal length varies, the movement of the optical axis ranges from zero to infinity, and the lens surface remains unchanged during movement. The focus can move in a 3D conical area. When the thickness of the LC layer is 30 μm, the fastest response time reaches only 0.635 s, much faster than now. [ABSTRACT FROM AUTHOR]

For decades, radiofrequency (RF)-induced tissue fusion has garnered great attention due to its potential to replace sutures and staples for anastomosis of tissue reconstruction. However, the complexities of achieving high bonding strength and reducing excessive thermal damage present substantial limitations of existing fusion devices. This study proposed a discrete linkage-type electrode to carry out ex vivo RF-induced intestinal anastomosis experiments. The anastomotic strength was examined by burst pressure and shear strength test. The degree of thermal damage was monitored through an infrared thermal imager. And the anastomotic stoma fused by the electrode was further investigated through histopathological and ultrastructural observation. The burst pressure and shear strength of anastomotic tissue can reach 62.2 ± 3.08 mmHg and 8.73 ± 1.11N, respectively, when the pressure, power and duration are 995 kPa, 160 W and 13 s, and the thermal damage can be controlled within limits. Histopathological and ultrastructural observation indicate that an intact and fully fused stomas with collagenic crosslink can be formed. The discrete linkage-type electrode presents favorable efficiency and security in RF-induced tissue fusion, and these results are informative to the design of electrosurgical medical devices with controllable pressure and energy delivery. [ABSTRACT FROM AUTHOR]

Microbial fuel cells (MFCs) offer a dual solution of generating electrical energy from organic pollutants-laden wastewater while treating it. This study focuses on enhancing MFC performance through innovative electrode design. Three-dimensional (3D) anodes, created from corncobs and mango seeds via controlled graphitization, achieved remarkable power densities. The newly developed electrode configurations were evaluated within sewage wastewater-driven MFCs without the introduction of external microorganisms or prior treatment of the wastewater. At 1,000°C and 1,100°C graphitization temperatures, corncob and mango seed anodes produced 1,963 and 2,171 mW/m2, respectively, nearly 20 times higher than conventional carbon cloth and paper anodes. An advanced cathode composed of an activated carbon-carbon nanotube composite was introduced, rivaling expensive platinum-based cathodes. By optimizing the thermal treatment temperature and carbon nanotube content of the proposed cathode, comparable or superior performance to standard Pt/C commercial cathodes was achieved. Specifically, MFCs assembled with corncob anode with the proposed and standard Pt/C cathodes reached power densities of 1,963.1 and 2,178.6 mW/ m2, respectively. Similarly, when utilizing graphitized mango seeds at 1,100°C, power densities of 2,171 and 2,151 mW/m2 were achieved for the new and standard cathodes, respectively. Furthermore, in continuous operation with a flow rate of 2 L/h, impressive chemical oxygen demand (COD) removal rates of 77% and 85% were achieved with corncob and mango seed anodes, respectively. This work highlights the significance of electrode design for enhancing MFC efficiency in electricity generation and wastewater treatment. [ABSTRACT FROM AUTHOR]

Measuring the electrical conductivity (EC) of plant substrates is an effective way to assess their nutrient content. This study aims to compare the performance of EC sensors with varying electrode sizes and spacings when embedded in a plant substrate. The range of electrode sizes and spacings varied from 0.1 mm to 10 mm. The EC electrodes were embedded in a porous plant substrate and subjected to wet–dry cycles. The results showed that the electrodes with larger electrode dimensions and spacing produce valid EC values. [ABSTRACT FROM AUTHOR]

The electrochemical CO2 reduction reaction (CO2RR), driven by renewable energy, provides a potential carbon‐neutral avenue to convert CO2 into valuable fuels and feedstocks. Conversion of CO2 into formic acid/formate is considered one of the economical and feasible methods, owing to their high energy densities, and ease of distribution and storage. The separation of formic acid/formate from the reaction mixtures accounts for the majority of the overall CO2RR process cost, while the increment of product concentration can lead to the reduction of separation cost, remarkably. In this paper, we give an overview of recent strategies for highly concentrated formic acid/formate products in CO2RR. CO2RR is a complex process with several different products, as it has different intermediates and reaction pathways. Therefore, this review focuses on recent study strategies that can enhance targeted formic acid/formate yield, such as the all‐solid‐state reactor design to deliver a high concentration of products during the reduction of CO2 in the electrolyzer. Firstly, some novel electrolyzers are introduced as an engineering strategy to improve the concentration of the formic acid/formate and reduce the cost of downstream separations. Also, the design of planar and gas diffusion electrodes (GDEs) with the potential to deliver high‐concentration formic acid/formate in CO2RR is summarized. Finally, the existing technological challenges are highlighted, and further research recommendations to achieve high‐concentration products in CO2RR. This review can provide some inspiration for future research to further improve the product concentration and economic benefits of CO2RR. [ABSTRACT FROM AUTHOR]

Background: Non‐ablative radiofrequency (RF) has been widely used in clinical and at‐home cosmetics devices. RF electrode geometry can influence the heat distribution in the tissue. This study analyzes the influence of geometric parameters of the electrode on the heat distribution in the layered tissue. Materials & methods: The finite element simulation of the electrothermal coupling field was performed to obtain the three‐dimensional (3D) temperature distribution of the four‐layer tissue. The electrode geometric parameters including the inter‐electrode spacing (5‐12 mm), width (1‐3 mm), length (3‐10 mm), shapes (bar, dot and circle), and the coupling gel's electrical conductivity (0.2‐1.5 S/m) were simulated. The maximum temperature at 2 mm depth (T‐2 mm) and the temperature difference (Tdiff) between the maximum skin surface temperature and T‐2 mm were obtained to evaluate the effectiveness and safety. Results: The effect of geometric parameters on the effectiveness and safety was mixed. The maximum T‐2 mm occurred with the 5 mm inter‐electrode spacing, 3 mm width, 10 mm length, the circle‐shaped electrode, and the 1.5 S/m coupling gel's electrical conductivity. The ratio of inter‐electrode spacing to width at around four can achieve rapid temperature rise and skin surface temperature protection. The electrode shape influenced the area of temperature rise in the tissue's cross‐section. The coupling gel's electrical conductivity should be close to that of the skin to avoid energy accumulation on the skin surface. Conclusion: The electrode's geometric parameters affect the effectiveness and safety of the RF product. This study has provided the simulation procedure for the electrode design. [ABSTRACT FROM AUTHOR]

CO2 reduction, two‐electron O2 reduction, and N2 reduction are sustainable technologies to valorise common molecules. Their further development requires working electrode design to promote the multistep electrochemical processes from gas reactants to value‐added products at the device level. This review proposes critical features of a desirable electrode based on the fundamental electrochemical processes and the development of scalable devices. A detailed discussion is made to approach such a desirable electrode, addressing the recent progress on critical electrode components, assembly strategies, and reaction interface engineering. Further, we highlight the electrode design tailored to reaction properties (e.g. its thermodynamics and kinetics) for performance optimisation. Finally, the opportunities and remaining challenges are presented, providing a framework for rational electrode design to push these gas reduction reactions towards an improved technology readiness level (TRL). [ABSTRACT FROM AUTHOR]

CO2 reduction, two‐electron O2 reduction, and N2 reduction are sustainable technologies to valorise common molecules. Their further development requires working electrode design to promote the multistep electrochemical processes from gas reactants to value‐added products at the device level. This review proposes critical features of a desirable electrode based on the fundamental electrochemical processes and the development of scalable devices. A detailed discussion is made to approach such a desirable electrode, addressing the recent progress on critical electrode components, assembly strategies, and reaction interface engineering. Further, we highlight the electrode design tailored to reaction properties (e.g. its thermodynamics and kinetics) for performance optimisation. Finally, the opportunities and remaining challenges are presented, providing a framework for rational electrode design to push these gas reduction reactions towards an improved technology readiness level (TRL). [ABSTRACT FROM AUTHOR]

CO2 reduction, two‐electron O2 reduction, and N2 reduction are sustainable technologies to valorise common molecules. Their further development requires working electrode design to promote the multistep electrochemical processes from gas reactants to value‐added products at the device level. This review proposes critical features of a desirable electrode based on the fundamental electrochemical processes and the development of scalable devices. A detailed discussion is made to approach such a desirable electrode, addressing the recent progress on critical electrode components, assembly strategies, and reaction interface engineering. Further, we highlight the electrode design tailored to reaction properties (e.g. its thermodynamics and kinetics) for performance optimisation. Finally, the opportunities and remaining challenges are presented, providing a framework for rational electrode design to push these gas reduction reactions towards an improved technology readiness level (TRL). [ABSTRACT FROM AUTHOR]

CO2 reduction, two‐electron O2 reduction, and N2 reduction are sustainable technologies to valorise common molecules. Their further development requires working electrode design to promote the multistep electrochemical processes from gas reactants to value‐added products at the device level. This review proposes critical features of a desirable electrode based on the fundamental electrochemical processes and the development of scalable devices. A detailed discussion is made to approach such a desirable electrode, addressing the recent progress on critical electrode components, assembly strategies, and reaction interface engineering. Further, we highlight the electrode design tailored to reaction properties (e.g. its thermodynamics and kinetics) for performance optimisation. Finally, the opportunities and remaining challenges are presented, providing a framework for rational electrode design to push these gas reduction reactions towards an improved technology readiness level (TRL). [ABSTRACT FROM AUTHOR]

High conductivity and mass transfer channels of electrode materials with high mass loadings are the fundamental requirements for achieving high‐rate performance and high‐volume energy density. In this study, we investigated the method of constructing high‐mass loading pellet electrodes and their applications in lithium metal batteries from three different perspectives: selecting active electrode materials, designing the mass transfer porous structure, and constructing a conductive network. The three‐dimensional conductive network with porous structures provides the electrolyte's mass transfer channels and convenient charge transfer paths. The resulting pellet electrode demonstrates Young's modulus of 511 MPa under 44 % porosity, achieving satisfactory rate performance under mass loadings of 37.7 mg cm−2. After 200 cycles at the current density of 2.83 mA cm−2, it can maintain 56 % initial capacity, and the volume expansion is only 8.04 %. This study provides reference values for exploring and preparing high‐mass loading electrodes and the future design of solid‐state battery electrodes. [ABSTRACT FROM AUTHOR]

Detection sensitivity is a crucial factor in the application of ECIS sensors. For these biosensors, the electrode configuration has a direct impact on sensitivity, yet few studies on monopolar electrodes have been reported. In this study, ECIS sensor arrays, which have a series of working electrode configuration with a wide diameter range and different electrode number, were fabricated to monitor living osteoblast-like MC3T3-E1 cells. The experimental results revealed that when the electrode diameter was larger than 25 μm, electrodes with smaller diameter and number yielded higher impedance values and generated more impedance shift to cell status change. The membrane capacitance obtained by equivalent circuit fitting was at the same level. When the electrode diameter was even smaller, the results in detection of cell monolayer were opposite, and there was no distinct relationship between impedance and membrane capacitance shift to cell status change and electrode geometry. The proposed sensor chip, allowing for a sustained and stable detection of cellular impedance, provides the basis for the selection of the electrode configuration of monopolar electrodes. The test results of electrodes with a diameter of 25 μm and lower indicated the possibility of single cell impedance measurement, which can provide unique insight into the heterogeneous electrical behavior of cells, and, in this case, the electrode size should be close to the cell size. [ABSTRACT FROM AUTHOR]

Li-sulfur batteries represent a promising class of next-generation batteries with high theoretical gravimetric capacity. Moreover, the absence of scarce elements such as nickel or cobalt makes them a sustainable alternative to Li-ion batteries. However, it is well known that the main problem of Li-sulfur batteries is the so-called polysulfide shuttle, which leads to self-discharge, capacity fading and low coulombic efficiency. In recent years, several mitigation strategies have been developed for Li-sulfur batteries to reduce the polysulfide shuttle effect. One promising approach is to covalently bond the sulfur to a polymer backbone. A well-known class of materials is sulfurized poly(acrylonitrile) (SPAN), for which long cycle life and high specific capacities have been reported. In this work, we present a novel continuum model for SPAN electrodes and demonstrate its application in Li-SPAN batteries. Within our simulation framework we include both red/ox reactions of covalently sulfur on PAN as well as transport and reactions of polysulfides in the solution. By combining simulations and experimental data we analyze the discharge mechanism and provide guidelines for electrode design. [Display omitted] • Continuum model of a Li-SPAN battery is presented for the first time. • Simulation results are compared to and in agreement with experimental data. • The model is able to describe the discharge mechanism of the SPAN material. • Transport in the electrolyte is limiting cell performance for thicker electrode with higher cell energy density. [ABSTRACT FROM AUTHOR]

This paper aims for developing topology optimization methodology to design the shape of electrodes in Dielectrophoresis (DEP)-based devices. The DEP force is due to a non-uniform electric field induced by applied voltages to the electrodes. Shape of the electrodes has the principal effect on the direction and magnitude of the DEP force. In medical therapy microfluidic devices, DEP force is used for cell sorting and cell separation. While the direction and magnitude of the DEP force are desired to be determined and maximized respectively, the magnitude of the electric field should be minimized to avoid damaging cells. Approaching these goals is counter intuitive where the existing electrode designs are basic. Therefore, a detailed finite element model (FEM) is developed for DEP force and electric field to formulate an optimization problem to maximize the DEP force in a particular direction while there is a constraint on electric field's magnitude. Using the developed FEM, explicit formulations for sensitivity analysis are derived to implement a gradient-based topology optimization. The performance of developed methodology is assessed numerically to determine the direction of the DEP force and constraining the electric field and experimentally in a practical case study of particle trapping in a microfluidic channel. • Topology optimization can produce novel electrode shapes for DEP devices. • Sensitivity analysis is provided for topology optimization of electrodes in DEP devices. • Optimal electrodes can determine direction of DEP force and minimize electric field. • 2D optimal electrodes are efficient in real 3D microfluidic applications. • Optimal electrodes are efficient for particle manipulation in a micro channel. [ABSTRACT FROM AUTHOR]

Various electrical connection configurations for piezoelectric nanofabrics (PNFs) fabricated from electrospun polyvinylidene fluoride (PVDF) nanofibers and yarns were realized through different electrode designs, including interdigitated wire electrodes, screen electrodes, core-sheath electrodes, and their combinations. The effects of the electrode designs and weaving modes were investigated on the electromechanical performance. It was found that the piezoelectric output of the PNFs in response to mechanical input was significantly improved by increasing the contact area between the electrodes and the active piezoelectric nanofibers, and thus enhancing the connectivity of all the conductive elements in the PNFs. Large output voltage magnitude (~1.4 V) was observed in the PNF samples made of piezoelectric core-sheath yarn with optimized electrode connection and coverage. Our results here clearly prove the high importance of electrical connection configuration to the performance of PNFs. We believe there is a great room to optimize electrode designs and electrical connections for improved piezoelectric fabric sensors and transducers. [ABSTRACT FROM AUTHOR]

Blasting erosion arc machining (BEAM) introduces a high-efficiency and low-cost machining technique in dealing with difficult-to-cut materials. Despite its high machining efficiency, the machined surface is quite rough. It leads to an excessive allowance for subsequent processing. This paper presents an optimized tool electrode design that enables an enhanced hybrid arc breaking mechanism. Both flow field simulation and machining test verify that the optimized electrode can guarantee a much better gap flow field and debris expelling effect. The corresponding machined surface is significantly improved in aspects of surface roughness, smoothness, uniformity, recast layer as well as heat affected zone. [ABSTRACT FROM AUTHOR]

Proton‐exchange membrane water electrolyzers (PEMWEs) will play a key role in future sustainable hydrogen production for mobility, households or chemical industry. Yet, the anode in PEMWEs, where the pivotal oxygen evolution reaction takes place, needs further improvement in terms of performance and cost. Both catalyst materials and electrode structure have to be optimized in order to inhibit degradation and reduce noble metal loadings. This review focuses on a holistic approach, covering all catalyst material, electrode structure, and transport layers within the framework of an overall electrode design, which not only optimizes the catalyst but also, all components of the electrode in conjunction. This review defines the goals for performance metrics of future PEMWEs in terms of power density and durability of the anode. Moreover, it summarizes manufacturing techniques and approaches that have a chance to be upscaled to meet the megawatt deployment of PEMWEs. The different aspects described jointly in this review such as novel catalyst system with higher intrinsic and structural performance or graded porous transport layers shall help to advance a next generation of electrodes. [ABSTRACT FROM AUTHOR]

This article investigates the dependence of transmitting sensitivity on the top electrode design of piezoelectric micromachined ultrasonic transducers (PMUTs). Two typical top electrodes, namely inner electrode (IE) and outer electrode (OE), are designed and fabricated. The measured transmitting velocities of the fabricated PMUTs at resonance under a drive voltage of 5 $\text{V}_{\mathrm {p-p}}$ (peak-to-peak) are 15.36 mm/s for the IE design and 20.67 mm/s for the OE design with a circular diaphragm and 16.62 mm/s for the IE design and 22.18 mm/s for the OE design with a hexagonal diaphragm. The OE design demonstrates a transmitting velocity improvement of 34.57% for the circular diaphragm and 33.45% for the hexagonal diaphragm. The improvement is due to the fact that the OE design shows higher quality factor (${Q}$) than the IE counterpart. Moreover, the resonant frequency of the OE design is higher than that of the IE design, which results in a larger acoustic pressure output and hence higher transmitting sensitivity. This work highlights an effective and simple approach for PMUTs to achieve high transmitting sensitivity, which is an important parameter in the applications that require large sound pressures, such as fingerprint imaging, gesture recognition, and ranging. [ABSTRACT FROM AUTHOR]

• Generation of traveling waves in one-dimensional beams by piezoelectric actuation. • The design variables are two sets of electrodes including the polarization direction. • The deflection of the beam is computed by modal decomposition. • An interpolation scheme for the selection of the set of electrodes is proposed. In this paper a milli-sized traveling wave actuator is designed by optimizing the polarization direction. Two different sets of electrodes are needed to generate the traveling wave. The topology optimization method is used to get the optimal sets of electrodes that minimize the difference between a pure traveling wave and the deflection generated. Classical issues in topology optimization problem such as mesh-dependence or intermediate densities are overcome by using filtering and projection techniques. Examples with different boundary conditions are presented in order to validate the model. [ABSTRACT FROM AUTHOR]

Rechargeable zinc–air batteries (ZABs) show enticing prospects as next‐generation energy conversion and storage technology due to their unique merits of environmental friendliness, low cost, impressive energy density, and high security. However, the dendrite growth, surface passivation, and metal anode corrosion, as well as the sluggish reaction kinetics, deficient bifunctionality, high platinum group metals (PGMs) dependence, and corrosion of carbon‐based materials for air cathodes, are the main problems hindering the large‐scale application of ZABs. Herein, the fundamental principles of ZABs are first introduced. The detailed discussions will be focused on the electrochemical aspects of the metal anode and air cathode by making a comprehensive comparison of the recent progress in the field. Lastly, brief perspectives on the further development of rechargeable ZABs are introduced. This review aims to provide a better understanding of electrode design for ZABs, which will provide guidelines for the design and fabrication of high‐performance and cost‐effective ZABs. [ABSTRACT FROM AUTHOR]

As the electrical stimulation (ES) may coexist with myoelectric signal (EMG) collection in a bidirectional human-machine interface, the compatibility of these two channels must be ensured at first. From the perspective of optimization, it is feasible to reduce the ES-introduced interference in the EMG signal by refining the electrode design. In this paper, a mathematical model of the electric field about ES noise propagation was first established and then verified using finite element analysis (FEA). Based on the model, a novel concentric electrode configuration with optimized electrode size used for biphasic transcutaneous electrical nerve stimulation (TENS) was proposed. The design was finally verified on both non-woven electrode and flexible printed circuit (FPC)-substrate electrode for reducing the ES noise in the myoelectric signal. This study can be used to guide the design of various TENS electrodes, whether they are monomeric or arrayed electrodes, in a typical bidirectional human-machine interface for improving the afferent/efferent signal compatibility. [ABSTRACT FROM AUTHOR]

Objective: Vertigo is a common side effect of cochlear implant (CI) treatment. This prospective study examines the incidence of postoperative vertigo over time and aims to analyze influencing factors such as electrode design and insertion angle (IA). Study Design and Setting: This is a prospective study which has been conducted at a tertiary referral center (academic hospital). Patients: A total of 29 adults were enrolled and received a unilateral CI using one of six different electrode carriers, which were categorized into "structure-preserving" (I), "potentially structure-preserving" (II), and "not structure-preserving" (III). Intervention: Subjective vertigo was assessed by questionnaires at five different time-points before up to 6 months after surgery. The participants were divided into four groups depending on the time of the presence of vertigo before and after surgery. Preoperatively and at 6 months postoperatively, a comprehensive vertigo diagnosis consisting of Romberg test, Unterberger test, subjective visual vertical, optokinetic test, video head impulse test, and caloric irrigation test was performed. In addition, the IA was determined, and the patients were divided in two groups (<430°; ≥430°). Main Outcome Measures: The incidence of vertigo after CI surgery (group 1) was reported, as well as the correlation of subjective vertigo with electrode array categories (I–III) and IA. Results: Among the participants, 45.8% experienced new vertigo after implantation. Based on the questionnaire data, a vestibular origin was suspected in 72.7%. The results did not show a significant correlation with subjective vertigo for any of the performed tests. In group 1 with postoperative vertigo, 18% of patients showed conspicuous results in a quantitative analysis of caloric irrigation test despite the fact that the category I or II electrodes were implanted, which are suitable for structure preservation. Average IA was 404° for the overall group and 409° for group 1. There was no statistically significant correlation between IA and perceived vertigo. Conclusions: Though vertigo after CI surgery seems to be a common complication, the test battery used here could not objectify the symptoms. Further studies should clarify whether this is due to the multifactorial cause of vertigo or to the lack of sensitivity of the tests currently in use. The proof of reduced probability for vertigo when using atraumatic electrode carrier was not successful, nor was the proof of a negative influence of the insertion depth. [ABSTRACT FROM AUTHOR]

Objectives: To determine the impact of age, electrode array, and time on impedance patterns in cochlear implant (CI) patients. Methods: A retrospective case review was performed on 98 patients implanted with the CI24RE perimodiolar (PM) and CI422 lateral wall (LW) arrays between 2010 and 2014 to assess impedances at the 1 week and 3-6 month visit after initial stimulation (IS). Results: With respect to age, impedances were higher in young patients compared to older patients in the middle and apical turns. With time, there were significant reductions in impedances across most electrodes. Electrode array type also had a significant impact on impedance measurements with PM and LW arrays having higher impedances in the basal turn and apical turns, respectively. Furthermore, PM arrays demonstrated significantly lower impedances in the middle and apical turn with time, when compared to LW arrays. Conclusions: Age, electrode array, and time can independently affect CI impedances. Moreover, we show that PM arrays may be advantageous to LW arrays, due to demonstrated lower impedances in the middle and apical turns long term. Understanding the impact of impedance on speech discrimination and determining the intracochlear processes that contribute to differences in impedance are future research directions. [ABSTRACT FROM AUTHOR]

In this study, the performance of electroactive bacteria (EAB), cultivated inside tubular electrode ducts, is systematically investigated to derive predictions on the behavior of EAB under conditions limited by electrochemical losses. A modeling approach is applied to assess the influence of the electrochemical losses on the electrochemical performance and scaling characteristics of complex 3D structures, such as sponges and foams. A modular flow reactor is designed that provides laminar and reproducible flow conditions as a platform for the systematic electrochemical and bioelectrochemical characterization of 3D electrodes in bioelectrochemical systems (BES). The bioelectrochemical experiments are carried out in a set of reactors incorporating cylindrical electrodes exhibiting ducts of 1 cm length and different diameters ranging from 0.1 cm up to 1 cm. Single duct calculations are extrapolated to three dimensions through geometrical considerations; trends in 3D bioanode performance are demonstrated using the resulting simplified 3D structure. The combined experimental and modeling approach constitutes a framework for future studies on systematic electrode design. [ABSTRACT FROM AUTHOR]

In order to help answering the question 'Which electrode design is the best?', the precipitation performance of a tubular electrostatic precipitator was determined for different electrode designs with special attention to specific energy consumption. Experiments were conducted in a wire–tube arrangement with a high loading of liquid submicron particles causing strong space charge effects, also known as corona quenching. The experiments are supplemented by numerical simulation results showing the effect of residence time and power consumption on separation efficiency. [ABSTRACT FROM AUTHOR]

Metal‐rich chalcogenides composed of highly abundant elements recently emerged as promising catalysts for the electrocatalytic hydrogen evolution reaction (HER). Many of these materials benefit from a high intrinsic conductivity as compared to their chalcogen‐rich congeners, greatly reducing the necessity for conductive additives or sophisticated nanostructuring. Herein, we showcase the high potential of metal‐rich transition‐metal chalcogenides for the electrocatalytic hydrogen formation by summarizing the recent progress achieved with M9S8 (pentlandite type) and M3S2 (heazlewoodite type) based materials, which represent the most frequently applied compositions for this purpose. By a detailed electrochemical comparison of bulk as well as pellet electrodes of metal‐rich Fe4.5Ni4.5S8, we also aim at raising awareness in the community for the inherent differences in catalytic properties of the materials themselves and those of the fabricated electrodes, a point that is often disregarded in reports on HER‐catalyst systems. [ABSTRACT FROM AUTHOR]

The urgency of achieving green chemical production through Cu-based CO 2 electroreduction necessitates a rapid transition towards technical maturity and commercialization in the pursuit of addressing the global imperative of decarbonization. Surprisingly, limited emphasis has been placed on exploration of readily scalable cell and electrode designs, which are pivotal in ushering in the era of stable and selective CO 2 electrolyzers, showcasing the innovative potential within this area. Herein, we report a breakthrough in achieving month-long stability in the production of C 2 H 4 , representing an unprecedented milestone in low-temperature CO 2 to C 2+ electrolysis. Initial investigations involved the evaluation of five distinct cell architectures for Cu-based CO 2 electrolyzers, guided by considerations of cell potentials, scalability with current technology, and CO 2 crossover. An innovative multilayer Gas Diffusion Electrode (GDE), featuring an anion exchange ionomer and metal oxide layer, is introduced for CEM-based zero-gap cells, enabling C 2 H 4 formation despite acidic surroundings. However, selectivity towards C 2 H 4 proved suboptimal for extended stability testing. Conversely, the tailored multilayer GDE for one-gap cell architecture achieves a commendable 54 % faradaic efficiency (FE) towards C 2+ products at 300 mA/cm2. Remarkably, chronopotentiometric tests demonstrate 720 h of stability (FE C 2 H 4 > 20 %) at 100 mA/cm2. At higher current densities (300 mA/cm2), stability is reduced to 75 h, with detailed analyses revealing distinct degradation mechanisms. At 100 mA/cm2, salt formation predominates, while at 300 mA/cm2, catalyst layer restructuring degrades catalytic activity towards C 2 H 4. Our research underscores the potential for stable, high C 2+ selectivity through innovative electrode design and scalable cell architectures, advancing sustainable CO 2 utilization. • Scalable CO 2 electrolyzer designs for C 2 H 4 production. • CEM-based zero-gap cell: Innovative electrode design to steer C 2 H 4 selectivity. • CEM-based one-gap cell: Optimized electrode design for high performance. • Stable C 2 H 4 production for 720 h at 100 mA/cm2 • Identified degradation causes: Salt formation (100 mA/cm2) and catalyst restructuring (300 mA/cm2). [ABSTRACT FROM AUTHOR]

Lithium-ion batteries are available in three primary configurations: cylindrical, prismatic, and pouch cells. The distinct shapes of these formats introduce variations in electrochemical performance and mechanical response. This study extensively investigates the influence of cell format on electrochemical and mechanical responses, expanding investigations with higher C -rates and next-generation battery materials exhibiting significantly larger expansion ratios. To the best of our knowledge, no simulation studies on large-scale cell format comparisons comprehensively considering the electrochemical and mechanical responses of the electrode design currently exist, especially for high expansion ratio materials. A physics-based 2D model integrating particles, electrodes, and cell levels was employed to achieve this, unraveling the interplay between mechanical and electrochemical reactions. Although stress improved electrochemical performance, the impact of geometric differences appeared minimal. However, significant volume expansion reduces the electrochemical performance and highlights format-driven variations, with pouch cells demonstrating superior electrochemical performance, followed by prismatic and cylindrical cells at 1C. The stress and strain patterns mimicked the concentration distributions, while the circular regions introduced uneven stress and deformation. Therefore, ensuring cell safety requires thicker separators in high-strain circular areas. This study presents a safe cell design, encompassing considerations of electrochemical and mechanical responses in current lithium-ion batteries and next-generation technologies. • Investigated electrochemical and mechanical responses across different cell formats. • Considered higher C -rates and higher expansion ratio materials. • Explored how distinct shapes impact voltage, concentration, stress/strain patterns. • Proposed a safer cell design, especially in high-strain circular regions. [ABSTRACT FROM AUTHOR]

• A novel electrode set is assessed for enhancing the electrocoalescence. • The geometry is ladder and V-shaped, and the electrodes are bare. • Both droplet–droplet and droplet–interface coalescence are promoted in this design. • Pulsatile DC fields are more effective in promoting coalescence than constant ones. • Optimum values of electrical parameters exist for the fluid physical properties. Electrocoalescence is an energy-efficient and environmentally-friendly process for breaking water-in-oil emulsions. It has been used extensively in the oil and petroleum industries. However, the current technology requires long residence times, giving rise to bulky vessels for industrial scale operations and making it less attractive for offshore application. It is also highly desirable to develop compact devices for down-the-well use. In this study, the performance of a novel electrode geometry, a ladder-shaped set of electrodes through which the emulsion flows, is assessed for enhancing the electrocoalescence, hence providing the potential for a compact design. The electrodes are formed into a V shape, with the apex pointing towards the direction of flow. This configuration enables nesting a series of electrodes in a compact form. Furthermore, the water-in-oil emulsion flows through the electrodes rather than passing by them, thus maximizing the effect of the electric field for coalescence. The system under study uses dispersed water droplets in sunflower oil, flowing in a narrow rectangular duct through the electrodes, providing essentially a two-dimensional flowing stream. The performance of this design is investigated for different electrical parameters (i.e. electric field intensity, frequency and waveform), fluid physical properties (i.e. conductivity and water content) and residence time. Of the three types of electric field waveform (i.e. half-sinusoidal, square and sawtooth), sawtooth performs best at high conductivities. Experiments reveal the existence of optimal values of electric field intensity, electric field frequency, salt concentration and water concentration, where the coalescence efficiency is maximum for the current design. Numerical simulation of the electrocoalescence process is conducted to assess the influence of various geometric and process parameters on the coalescence mechanisms of the V-shape electrodes. The outcome of this work is potentially useful for optimizing the design of compact and efficient oil–water separators. [ABSTRACT FROM AUTHOR]

The 3-D finite-element model (FEM) of a Y-cut plano-plano langasite crystal thickness shear mode (TSM) resonator is presented, and Mindlin’s theory is used to investigate the optimal electrode shapes and sizes for langasite crystal resonator. Circular and elliptical electrodes of various arc lengths are studied to identify the most optimal electrode design configuration in order to achieve TSM vibration free from any anharmonic modes. Simulation results show that resonators with elliptical electrodes have noticeably better suppression of spurious modes compared to that of circular electrodes. Moreover, spurious mode suppression is accomplished for multiple electrode sizes for the same shape, which greatly differs from Mindlin’s theory. Hence, three optimized designs are shortlisted and their mass loading sensitivities are investigated. Circular and elliptical electrodes of the same area show similar responses to added mass, indicating that elliptical electrodes have no apparent advantage over circular electrode in mass sensing applications. [ABSTRACT FROM AUTHOR]

Abstract This work aimed at evaluating the effects of high-voltage electric field (HVEF) produced by an improved electrode system on the freezing behaviors and selected properties of agarose gel. The freezing of the agarose gel was realized by a Peltier cooler coupled with an improved electrode system. The electrode system was integrated with a dielectric spacer having high permittivity to avoid partial discharges. Results showed that HVEF combined with a low freezing rate significantly reduced the supercooling degree, enhanced the average freezing rate in particular the nucleation rate, and higher internal electric field intensity showed a better microstructure with smaller ice crystals in frozen samples. Under the highest applied voltage of 9 kV ( E i n = 1.09 E+05 V/m) tested in this study, a 100% supercooling release was achieved. Maximum reductions of 78.83%, 25.79% and 28.75% were observed for the nucleation time, tempering time and total freezing time, respectively, while the phase transition time was prolonged by 14.86% as compared with the control (p < 0.05). Some reinforcement was detected in the gel strength by increasing internal electric field intensity, but not significant enough to prevent the structural damage and syneresis caused by freezing and thawing. This study suggested that HVEF-assisted freezing was able to reduce the size of ice crystals formed in semi-solid model foods, and the integration of a dielectric spacer with high permittivity to the electrode could be used as a potential method to solve the electrical discharge problem. Highlights • An improved electrostatic freezing (EF) system was developed. • Electrodes with dielectric spacer could strengthen the internal field intensity. • EF reduced supercooling degree and enhanced freezing rate. • EF enhanced gel strength but did not prevent freezing damage. • EF reduced the size of ice crystals formed in agarose gel. [ABSTRACT FROM AUTHOR]

In the orbital mode of electrical discharge machining (EDM), an electrode with a complex profile causes deviation in the cavity profile from the design objective. In this paper, electrode compensation techniques according to the envelope theory are presented to eliminate deviation errors. The succession of orbits traced out a family of electrode curves based on kinematic geometry integrated with the motion path of tool bodies and constraints. The boundary of the family of electrode curves is referred to as the orbiting profile. The deviation error between the orbiting and objective profiles can be eliminated by using a compensation electrode in the orbiting process. Thus, the generated orbiting profile conforms to the objective profile. Experimental results of the tested example for the machining profile of the compensation electrode by using the orbital process revealed that profile deviation can be eliminated to ensure that the EDM profile closely conforms to the objective profile. This compensation method for orbiting EDM provided an exact process to engineers for easy control of the machining precision of EDM. [ABSTRACT FROM AUTHOR]

Atmospheric ice accretion is considered a severe safety issue for technical systems such as communication infrastructure, power lines, blades of wind turbines, and so on in cold climate regions. Among different sensing systems to detect and provide reliable information about the state of ice, capacitive sensing has been reported as a suitable technique. In capacitive sensing, measured capacitances are influenced due to ice accretion. Signal processing for ice sensors requires to estimate parameters for the state of ice from the data. In this paper, we present a model-based estimation approach for capacitive ice sensors. We analyze different electrode topologies for ice sensing and provide a statistical analysis of the sensor behavior. We hereby consider the random nature of natural ice accretion. From simulations, we show how a statistical model for the measurement process can be derived and demonstrate the construction of estimation algorithms within the Bayesian framework. We will demonstrate the capability of our approach for automated ice detection by means of long-term field data showing the ability to estimate ice layers with a precision better than 1 mm. [ABSTRACT FROM AUTHOR]

As a promising large-scale energy storage device, the vanadium redox flow battery (VRFB) has attracted attention due to its excellent safety, the independence between energy capacity and power capacity, the suitable polarization potential, and the ability to avoid cross-contamination. In this work, a 3D model of VRFB is developed based on the open-source computational fluid dynamics (CFD) platform OpenFOAM, which is well-validated. Then, the effect of operating conditions is studied, which shows that a higher electrolyte concentration can reduce the overpotential and increase the discharge voltage. Reducing the current density can increase the deepness of charge and discharge, reduce the electrolyte concentration gradient, the mass transfer loss and the activation loss. In addition, the effect of electrode porosity is studied that the overpotential decreases near the membrane and increases near the current collector with increasing porosity. Finally, the effect of porosity changes in different directions is studied, and an attempt is made to utilize this overpotential distribution by introducing the gradient-porosity electrode to reduce the non-uniformity of overpotential. The gradient-porosity electrode design using higher porosity near the membrane and lower porosity near the current collector can effectively improve the distribution of overpotential and increase battery performance by 1.67 mV. [Display omitted] • A VRFB model is developed under open-source environment OpenFOAM. • The effect of electrolyte concentration and current density is studied. • The overpotential distribution pattern caused by different porosity is summarized. • The performance with the gradient-porosity electrode is increased by 1.67 mV. [ABSTRACT FROM AUTHOR]

Objective: The ideal form of a neural-interfacing device is highly dependent upon the anatomy of the region with which it is meant to interface. Multiple-electrode arrays provide a system that can be adapted to various neural geometries. Computational models of stimulating systems have proven useful for evaluating electrode placement and stimulation protocols, but have yet to be adequately adapted to the unique features of the hippocampus. Methods: As an approach to understanding potential memory restorative devices, an admittance method-NEURON model was constructed to predict the direct and synaptic response of a region of the rat dentate gyrus to electrical stimulation of the perforant path. Results: A validation of estimated local field potentials against experimental recordings is performed and results of a bilinear electrode placement and stimulation amplitude parameter search are presented. Conclusion: The parametric analysis presented herein suggests that stimulating electrodes placed between the lateral and medial perforant path, near the crest of the dentate gyrus, yield a larger relative population response to given stimuli. Significance: Beyond deepening understanding of the hippocampal tissue system, establishment of this model provides a method to evaluate candidate stimulating devices and protocols. [ABSTRACT FROM AUTHOR]

Single ion conductors, such as solid electrolytes are promising alternatives to overcome drawbacks of lithium-ion batteries with binary electrolytes, e.g. thermal runaway and electrolyte decomposition. Within this research a pseudo-two-dimensional (P2D) battery model for cells with single ion conducting electrolytes is derived and compared to a state of the art P2D model for cells with binary electrolytes to elucidate the theoretical differences in cell performance when replacing binary with single ion conducting electrolytes, as well as the related advantages and bottlenecks. At high discharge rates, electrolyte potential losses are more distinct for binary electrolytes compared to single ion conducting electrolytes which results in a higher energy for the latter one. Further, sensitivity to variations in electrode and electrolyte are elucidated analyzing discharge curves, Electrochemical Impedance Spectroscopy (EIS) and maximal energy. Parameter variations indicate that single ion conducting electrolyte cells allow thick electrode designs. They can therefore be advantageous to classical binary electrolyte cells when building high energy cells, once the high conductivities of laboratory studies found their way into application. [ABSTRACT FROM AUTHOR]

A hybrid Zn battery is developed by integrating a Zn-Co 3 O 4 battery and a Zn-air battery at the cell level, which combines the unique advantages of a high working voltage and a high discharge capacity. However, the design of the working electrode, which is the key to the battery performance, is absent in the literature. In this work, the electrode design of hybrid Zn-Co 3 O 4 /air batteries for performance improvements is investigated by considering the active material loading and the surface hydrophobicity of the Co 3 O 4 nanosheet-decorated carbon cloth electrode. The results demonstrate that the capacity of the Zn-Co 3 O 4 battery first dramatically increases with the loading, but the improvement becomes limited when the loading further increases. The discharge voltage plateau of the Zn-air battery increases first and then keeps decreasing. The reason is that although both the active material and the surface area increase, the increased dimension of nanosheets increases the transport resistance, especially for electrons and oxygen. For a given electrode, the discharge voltage of the Zn-air battery first increases with an increase of the hydrophobicity due to the creation of gaseous oxygen transport pathway, but then decreases due to the coverage of active sites. While both the voltage and the capacity of the Zn-Co 3 O 4 battery decrease with the hydrophobicity, which is attributed to the decreased contact surfaces between the reactant and the liquid electrolyte. Based on the optimized active material loading and surface hydrophobicity, a hybrid Co 3 O 4 /air battery delivers a high energy density of 936 Wh kg −1 (on the weights of Co 3 O 4 and consumed Zn) and stable discharge and charge voltages ranging from 0.94 V to 2.01 V for 400 cycles. This work illustrates that for high-performance hybrid batteries, the active material loading of the electrode should be well designed considering the transport of electrons and oxygen, and a balance between the hydrophobicity and hydrophilicity should be established. [ABSTRACT FROM AUTHOR]

Silicon-graphite composite electrode is one of the most practical solution for next generation high performance lithium ion batteries. Electrode geometry design is a new strategy to improve the electrochemical performances. Herein, we report a unique hierarchical structure of Si@alginate microcapsule-graphite composite anode, in which Si microcapsules are prepared by wrapping of calcium cross-linked alginate. The Si@alginate microcapsules are uniformly dispersed in graphite anode with the widely adopted CMC and SBR binder. The new geometry of electrode architecture has locally different binder systems, which enables both Si and graphite run in their optimized binder environment. The cross-linked alginate capsule effectively confines the volume change and prevents aggregation of the Si nano-particles, which contribute to a significant improvement of the electrochemical performances. At a weight ratio of 3:7 between Si and graphite, the composite electrode exhibits a reversible capacity of 916 mAh g −1 and a capacity retention of 92.4% after 200 cycles. The new strategy for hybrid anode represents a promising avenue for the mass production of high performance Si-graphite composite anode in the future. [ABSTRACT FROM AUTHOR]

Taking advantage of a high theoretical energy density of 2567 Wh kg -1 , lithium sulfur batteries (LSBs) have been considered promising candidates for next-generation energy storage systems. Nevertheless, challenging issues involving both sulfur cathode and lithium anode hinder their practical applications, which are followed by the extensive research efforts to resolve them. A wide variety of carbon nanomaterials with different characteristics has played an important role in enhancing the performance of LSBs via immobilizing sulfur in cathodes, accommodating the volume expansion of sulfur, enhancing the reaction kinetics and stabilizing lithium anodes. This report overviews the state-of-the-art progress in designing and fabricating nanocarbon for advanced LSBs with particular focuses on the correlations among porosity, electrical conductivity and surface chemistry as some of the most critical factors. More importantly, statistical analysis of electrochemical performance of batteries collected from literatures allows us to identify substantial disparities between the current achievements and the requirements for real-world applications. In an effort to bridge this gap, we highlight recent advances in the design of LSBs with improved sulfur loading, enhanced charge transfer and minimized electrolyte/sulfur ratio. Conclusions and perspectives for future development of nanocarbon in LSBs are proposed. [ABSTRACT FROM AUTHOR]

The electrocatalytic reduction of carbon dioxide (CO 2 RR) is a crucial technology to develop the decarbonisation strategy for carbon circularity and producing solar fuels substituting fossil fuels. This viewpoint discusses the role of the electrode and reactor design as the main factor in determining the performance of CO 2 RR, at least under reaction conditions relevant to industrial scalability, evidencing the need to overturn the current strategic vision focused more on improving the characteristics of the electrocatalytic materials. Many parameters characterising the performances (such as Faradaic efficiency, carbon selectivity and potential onset, besides the current density) are strongly influenced and typically dominated (under relevant conditions) by the effective population of adspecies on the electrode surface, which is, in turn, related to mass control and transport resistances, local pH changes, multiphase boundaries, wettability and other aspects. Even the preliminary screening of the catalysts could be incorrect, not operating under representative conditions, and thus without properly choosing the electrode and reactor. Advanced electrode/reactor designs, e.g., based on gas-diffusion electrodes (GDEs) that avoid having a liquid electrolyte (zero-gap design), are necessary to improve CO 2 RR scalability to industrial applications. Even in situ catalyst nanoparticle reconstruction may depend on these aspects. Electrochemical characterization methods like electrochemical impedance spectroscopy (EIS) are the right approach to study electrocatalytic reactions, providing crucial indications on the effective controlling elements that determine the electrocatalyst/electrode performances. [Display omitted] • status and perspectives for electrode and reactor design in CO2RR. • advanced electrode/reactor designs based on GDE and zero-gap design for the cell. • electrochemical impedance spectroscopy to understand the performance-controlling aspects. • role of mass control and transport resistances, local pH changes, multiphase boundaries. • role of electrode/reactor design in determining the mechanism of CO2 conversion. [ABSTRACT FROM AUTHOR]

Silicon (Si) is one of the most promising next generation anode materials for lithium-ion batteries (LIBs), but the use of Si in LIBs has been rather limited. The main challenge is its large volume change (up to 300%) during battery cycling. This can lead to the fracture of Si, failure at the interfaces between electrode components, and large dimensional change on the cell level. To optimize the Si electrode/battery design, a model that considers the interactions of different cell components is needed. This paper presents the development of a multiphysics microstructure-resolved model (MRM) for LIB cells with a-Si anode. The model considered the electrochemical reactions, Li transports in electrolyte and electrodes, dimensional changes and stresses, property evolution with the structure, and the coupling relationships. Important model parameters, such as the diffusivity, reaction rate constant, and apparent transfer coefficient, were determined by correlating the simulation results to experiments. The model was validated with experimental results in the literature. The use of this model was demonstrated in a parameter study of Si nanowall|Li cells. The specific and volumetric capacities of the cell as a function of the size, length/size ratio, spacing of the nanostructure, and Li + concentration in electrolyte were investigated. [ABSTRACT FROM AUTHOR]

Electrode design is investigated for electrical capacitance tomography on a 1 mm-thick 3D planar domain. Arrays of square electrodes are located on both sides of the domain, which is filled with dielectric material. Anomalies of interest are voids in the material with low dielectric constant. Simulated tomography is conducted with various electrode patterns over a range of electrode sizes in order to compare performance. The high-aspect-ratio domain requires a large finite element mesh for simulating electric fields and for defining spatial sensitivity responses of electrode pairs. Compared to the canonical 2D pipe cross-section problem, this high-aspect-ratio system requires solving the reconstruction problem on a much larger mesh and is more severely underdetermined. An efficient methodology for characterizing the sensitivity responses of various electrode pairs is developed. An image reconstruction algorithm creates binary images by sequentially composing a list of occupied cells, conditioned with a cell-to-cell energy formulation. A parametric study of four candidate electrode patterns is conducted using electrode sizes between 0.8 mm and 1.6 mm, in which each potential design is used to perform tomographic reconstruction of 100 images. A new image-error metric is proposed, which is used to evaluate each electrode design. It is found that an electrode matrix pattern on each substrate, with the patterns offset, results in lower mean image error than other candidate patterns. [ABSTRACT FROM AUTHOR]

Single-plate digital microfluidic devices offer a set of advantages over two-plate devices such as better mixing, the ability to move larger volumes, and easier access to the droplet. Currently, the non-floating configuration, where all non-energized electrodes on the device are grounded, is the most common electrode switching scheme used in single-plate devices. However, this scheme is limited by the symmetry of the electric field around the energized electrode, which can prevent complete droplet transport to the energized electrode for small droplets that can be seamlessly manipulated on two-plate devices. Here we present a numerical model to analyze the effect of droplet volume on the electrical forces generated on droplets actuated on single-plate digital microfluidic devices. We show that the commonly used non-floating switching scheme has a limit on the smallest droplet volume it can manipulate even if the droplet base diameter is larger than the electrode length; a condition that is currently believed sufficient for complete droplet movement. The model we built used Maxwell Stress tensor to calculate the electrical forces on the droplet to capture the effect of the grounding scheme more accurately than the contact angle change model. We used this model to analyze movability of droplets of various volumes and contact angles to find the minimum volume that can be successfully actuated. We also suggest better electrode designs that improve actuation of small droplets on single-plate devices and make their performance comparable to two-plate devices. [Display omitted] • Droplet full transport to the energized electrode is not guaranteed even if the diameter of the droplet base is larger than the electrode length. • Symmetry of the electric field may cause droplets to stop halfway to the energized electrode. • Analysis of the physics behind this behavior is presented through numerical modeling and preliminary experimentation. • New device designs that improve the movability of small droplets are presented. [ABSTRACT FROM AUTHOR]

In this paper, we report the simulation and fabrication of thickness-shear mode langasite resonators with stepped elliptical electrode designs to investigate their effects on energy trapping and suppression of spurious modes at elevated temperatures. Finite element analysis was conducted to analyze the design of a stepped elliptical electrode on a contoured langasite crystal. Based on the simulation findings, langasite resonators with stepped electrodes were fabricated, and their displacement profiles and frequency–temperature properties were characterized using network analysis and laser Doppler vibrometry. Results demonstrate improved frequency separation between the resonant and spurious modes, and enhanced spurious mode suppression at both room and higher temperatures, suggesting that stepped elliptical electrode designs can effectively enhance the sensing performance of langasite resonators. • Langasite resonators with stepped elliptical electrodes are reported. • Effects of stepped electrodes on energy trapping and spurious modes are investigated. • Analysis shows enhanced suppression of spurious modes with stepped electrodes. • Separation between resonant and unwanted modes improved, even at high temperatures. [ABSTRACT FROM AUTHOR]

Short electrode life has been one of the crucial issues for aluminium resistance spot welding in high-volume automobile manufacturing. A fair amount of heat may be generated at the electrode/workpiece interface because of the high electrical contact resistance of the aluminium oxide layers. Correspondingly, rapid electrode degradation is observed due to severe Cu–Al alloying, pitting and cavity during welding. This issue has not yet been fully addressed. This survey focuses on the current studies of understanding and development of electrode life improvement specifically on those that extend electrode life via optimising the electrical contact resistance at the interface, including altering the surface conditions of the workpiece, weld parameters development and weld equipment selections, and new electrode designs, and etc. [ABSTRACT FROM AUTHOR]