FeCl3/KOH two steps activated biocarbon with hierarchical porosity and oxygen-rich for enhanced supercapacitor applications

An X-ray ionization beam position monitor (XIBPM) has been developed and evaluated for beam position diagnostics at a soft X-ray free-electron laser (FEL). The redesign was guided by electrostatic simulations and focused on mitigating electric-field distortions near the microchannel plate (MCP) and improving the internal electrode geometry and structural stability. The introduction of a conductive shielding cover effectively suppressed electric-field distortion from the MCP lead, substantially reducing displacement errors and improving measurement stability. A mesh-free electrode structure was also investigated, reducing photo-ion loss and increasing photo-ion transmission; however, under high-intensity FEL operation, the enhanced signal amplitude occasionally led to saturation effects. Beam position measurements were performed at photon energies of 500-1100 eV in both pink-beam and mono-beam modes. Under optimized conditions, a beam position resolution of approximately 24-25 µm was achieved for pulse-by-pulse analysis and improved to approximately 10-12 µm when averaging over ten pulses. The transverse ion profiles were found to be significantly broader than the actual photon beam size, reflecting intrinsic ion-transport dynamics and detector point-spread effects that dominate over the intrinsic photon beam size. These results demonstrate that the shielding cover represents the most significant improvement for accurate and stable beam position monitoring, while the electrode configuration can be selected flexibly depending on the operating regime. The improved XIBPM provides a practical, non-invasive solution for beam position diagnostics in soft X-ray FEL beamlines.

• Pump voltage distribution orders of 3, 5, 11, 13 generate quadratic nonlinearities • Ideal sense dynamics require drive alignment and nonlinear frequency balancing • Pump voltage phase must be varied when adjusting parametric amplification • Larger parametric amplification suppresses imperfection effects on rate output gain In this paper quadratic electrostatic forces are used to apply tunable parametric excitation to enhance rate-sensitivity in imperfect capacitive ring-based Coriolis Vibrating Gyroscopes (CVG) subjected to electrostatic nonlinearity. Using a mathematical model, implementation is achieved by selecting electrode configurations capable of decoupling the drive, tuning and parametric excitation whilst achieving ideal device performance. For a 16 electrode device operating in the n = 2 in-plane mode it is shown that parametric excitation can be generated by applying a harmonic pump voltage with spatial distributions of m p = 3, 5, 11 or 13. For m p = 3, conditions are obtained for the pump voltage amplitude and phase to achieve nonlinear frequency balancing to trim the CVG at a chosen operating amplitude whilst amplifying the rate output and sensitivity. It is found that the level of imperfection and electrostatic nonlinearity modify the required pump voltage phase, and the phase changes as the pump voltage amplitude is increased to enhance parametric amplification. It is also shown that large pump voltage amplitudes desensitise the rate sensitivity gain to the effects of imperfection. Theoretical results are presented to demonstrate enhanced rate sensitivity, and are validated against results obtained using the finite element method. Results are also presented to investigate the effect of mechanical damping on non-resonant coupling and the pump voltage needed to enhance rate sensitivity gain.

Lithium metal batteries (LMBs) have garnered considerable attention owing to their high theoretical capacity and low electrochemical potential; however, their practical implementation is hindered by unstable Li plating/stripping and poor interfacial stability. Previous strategies have largely focused on enhancing lithiophilicity or wettability to regulate initial Li deposition, yet they do not necessarily ensure stable long-term cycling. In this study, an interfacial buffer layer was rationally designed for metal-based current collectors to elucidate the distinct contributions of lithiophilicity and wettability to Li deposition behavior. A comparison of representative material systems designed to decouple these effects revealed that interfacial stability, derived from mechanical robustness and adhesion, governs long-term electrochemical performance. Bare Cu induces localized Li nucleation and forms a compositionally heterogeneous and unstable solid electrolyte interphase (SEI), leading to dendritic growth and dead Li accumulation. Conversely, a graphene oxide-poly(vinylidene fluoride)-coated current collector enables uniform Li deposition and promotes the formation of a mechanically robust and chemically homogeneous SEI, improving plating/stripping reversibility. The submicron-thick coating enables effective interfacial control without compromising practical electrode configurations. The resulting system delivers a stable coulombic efficiency of ∼75% over 120 cycles, whereas other configurations exhibit rapid degradation due to interfacial instability. XPS depth profiling revealed the formation of a uniform and lithium fluoride (LiF)-rich SEI with minimal depth-dependent variation, indicating a stabilized interphase. These findings highlight that long-term stability in LMBs is governed by mechanically robust interfacial stability during repeated cycling rather than by initial nucleation behavior, providing clear design guidelines for interface-engineered current collectors.

Nanosecond pulsed electric field (nsPEF) exposure can disrupt and disaggregate amyloid-β, indicating its potential to improve symptoms of Alzheimer's disease. However, the propagation and distribution patterns of nsPEF within brain tissue remain insufficiently understood, making related simulation analysis necessary. In this study, a high-resolution three-dimensional human head model incorporating the scalp, skull, cerebrospinal fluid, gray matter, white matter, and hippocampus was constructed. Based on the spectral characteristics of nsPEF, the dielectric properties of human tissues at different frequency ranges were assigned, and a transient finite-element model of nsPEF exposure in the human brain was established. The simulation analysis identified two optimal electrode-pair positions and characterized the spatial distributions of intracranial electric field strength as well as current density. It further elucidated the dependence of the hippocampal electric field response and current density on pulse parameters. In addition, a physical human brain model was constructed to experimentally validate the finite-element simulation results. The results showed that transcranial nsPEF can reach deep brain regions with extremely narrow pulse widths, and pulsed electric fields with kilovolt-level amplitudes and nanosecond-scale pulse widths can generate electric field strengths of approximately 10 3 V/m in the hippocampus. In summary, this work provides a theoretical basis and experimental support for optimizing the electrode configuration and stimulation parameters of transcranial nsPEF, thereby laying a foundation for future research on its application in non-invasive physical interventions for Alzheimer's disease.

All-solid-state lithium-sulfur batteries offer high energy density and enhanced safety. However, their practical application is hindered by high external operating pressure to mitigate mechano-chemical failures at interfaces. Here we show a strain-coordination strategy that leverages the opposite volume changes of electrodes during cycling to reduce electrode-level stress evolution and the external pressure required for stable operation. Using an FeS2 positive electrode and a prelithiated Si negative electrode as a representative system, we modulate the Li-to-Si ratio to achieve a near-zero-strain effect, where the expansion of FeS2 and the contraction of Li2Si partially counterbalance each other. This self-compensated electrode configuration mitigates mechano-electrochemical degradation under reduced pressure. As a result, the all-solid-state lithium-sulfur batteries deliver a discharge capacity of 868.4 mAh g⁻1 at 15 MPa. Under 100 MPa, the cells achieve an areal capacity of 21.7 mAh cm⁻2, and cycle life 4500 cycles at 1 C (60 min) and 140,000 cycles at 15 C (4 min). Furthermore, low-pressure all-solid-state pouch cells achieve stable cycling over 500 cycles at 15 MPa. This strain-coordination strategy provides an approach for enabling stable operation of all-solid-state batteries under reduced external pressure.

ABSTRACT A half-shifted dual-electrode parallel-aligned fringe-field switching (PA-FFS) liquid crystal device is proposed. The effects of electrode configuration and cell gap on electric-field distribution, molecular rotation behaviour, transmittance, and response time are investigated using three-dimensional numerical simulations. The results show that thinner cell gaps provide higher transmittance, whereas thicker cell gaps exhibit more favourable PA-FFS driving characteristics with reduced interaction between the upper and lower LC layers. By redistributing and compensating the virtual-wall regions through the half-shifted electrode configuration, high transmittance can be achieved without significantly sacrificing response speed. The proposed structure therefore demonstrates strong potential for high-performance applications in photonics and virtual-reality (VR) displays that require both fast response and high optical efficiency.

Spinal cord stimulation (SCS) is an established treatment for chronic pain. However, there is a clear opportunity for improvement as only approximately 60% of patients report a 50% or greater reduction in pain. In this study, we propose a novel approach, termed dual-frequency spinal cord stimulation (dfSCS), that is designed to exploit the underlying putative mechanisms of SCS-Gate Control Theory-by dispersing SCS-mediated excitation in time while preserving SCS-mediated inhibition. We simulate dfSCS, using a validated computational model of the spinal cord dorsal horn, by delivering 2 simultaneous stimulation frequencies to Aβ dorsal column axons representing the painful and surrounding region dermatomes. We experimentally compared dfSCS patterns that the model indicated were robust to variation in the axonal populations activated, as well as progressive loss of GABAergic inhibition typical in chronic pain, against conventional single-frequency SCS in male spared nerve injured rats. Dual-frequency spinal cord stimulation targeted to vertebral levels T12/T13, where the largest population of dorsal column projections from the hypersensitive sural nerve territory and surrounding dermatomes are located, increased responder rates over conventional stimulation. The optimal dfSCS frequency combination depended on both the orientation of the bipolar electrode stimulation and the rostrocaudal placement over the cord. Paw withdrawal threshold testing revealed either 2 Hz:54 Hz or 25 Hz:40 Hz as the most effective stimulation pair, depending on mediolateral vs rostrocaudal electrode configuration and vertebral level of stimulation, with rodent responder rates up to 100%. Overall, dfSCS is a promising approach to improving the efficacy of SCS for neuropathic pain.

Leukocyte analysis constitutes a fundamental pillar in clinical hematology due to the dynamic variations in subpopulation profiles during pathological processes, such as infections and inflammation. While impedance flow cytometry provides a label-free differentiation strategy based on intrinsic electrical properties, it is constrained by position-dependent signal variation and microchannel clogging. To address these limitations, we proposed a monolithically integrated microfluidic device that synergistically combined a bulk acoustic wave (BAW) resonator with coplanar edge electrodes projecting into one side of a wide microchannel. This design strategically concentrates the electric field intensity to a localized region near the electrodes, effectively eliminating clogging risks and enhancing detection sensitivity. Simultaneously, the BAW-induced acoustic streaming enables precise three-dimensional (3D) cell focusing, thereby circumventing the impact of the inherent nonuniform electric field. Additionally, the sheath-free focusing trajectory is flexibly tunable via modifications to the resonator geometry, enabling facile alignment with electrode properties for optimal cell positioning within the sensing zone. This design yielded a 5.04-fold enhancement in detection sensitivity compared to conventional electrode configurations. By characterizing both cell size and internal complexity through multifrequency impedance responses, the system achieved 3-part leukocyte classification comparable to hospital test reports, demonstrating its potential for practical medical and point-of-care testing (POCT) applications.

Abstract Developing spacecraft electrical systems with higher power and voltage levels is a key optimization direction in current spacecraft engineering, with a mainstream trend and research focus on elevating the voltage level to 400 V. However, during the on-orbit operation, the outgassing of internal materials creates a low-pressure environment, and electrode discharge in this low-pressure atmosphere can casue insulation failure. Existing research on electrode structures is insufficient to support the design requirements for high-power and high-voltage applications. In this paper, using FR-4 as the insulating substrate and brass as the electrode material, six typical spacecraft electrode structures including screw electrodes, busbar electrodes and circular electrodes are designed. Through a combination of experiments and simulations, the effects of electrode configuration and gas pressure on the discharge voltage (V d ) and extinction voltage (V e ) are investigated in a nitrogen environment ranging from 1 to 1000 Pa. The results indicate that the discharge characteristics of all samples exhibit Paschen-like curve features, and the electrode structure influences the discharge threshold by regulating the discharge path length and the electric field concentration. The H-type busbar structure demonstrates optimal performance due to its long discharge path and diffused electric field distribution, achieving a minimum V d of 678 V. In contrast, traditional busbar electrodes and circular electrodes exhibit a minimum V d of only about 360 V, and coating with PI film does not significantly improve insulation performance. These findings provide key data support and engineering guidance for the design and protection of next-generation high-voltage insulation structures in spacecraft.

This study presents a dataset of electrospinography (ESG) signals recorded from the human spinal cord during gait-related activities and motor imagery tasks. The dataset was acquired as part of a broader initiative to develop a spinal-machine interface (SMI) for closed-loop control of lower limb exoskeletons. ESG signals were collected using high-density surface electromyography (HD-sEMG) electrodes from fourteen able-bodied participants performing baseline trials (2), movement execution tasks (12) and motor imagery tasks conducted both in static conditions (5) and during movement (5). The dataset encompasses multiple electrode configurations targeting the brachial and lumbar plexuses, as well as surrounding musculature, across three experimental protocols. A total of 10 sessions were recorded for Experiment 1 (one 64-electrode matrix), 10 sessions for Experiment 2 (two 32-electrode matrices) and 5 sessions for Experiment 3 (two-32 electrode matrices). Preprocessing techniques were applied to mitigate cardiac and motion artifacts. The data provides a valuable and pionneering resource for advancing neurorehabilitation research, allowing the refining of exoskeleton control strategies and improving artifact removal methods.

BackgroundTumor Treating Fields (TTFields) provide a noninvasive treatment option for newly diagnosed glioblastoma. While electrode placement is considered important for treatment efficacy, current clinical planning relies on a proprietary and undisclosed software (NovoTAL). This study investigates a new computational approach for optimizing TTFields electrode placement and compares it with the current clinical standard.MethodsWe developed a computational pipeline integrating patient-specific anatomical data to optimize electrode configurations in five representative glioblastoma cases spanning diverse tumor locations and sizes. Two optimization strategies were investigated: one maximizing electric field intensity at the tumor and another increasing coverage of the surrounding brain while maintaining tumor intensity. Results were compared with electrode placements generated by NovoTAL. Additional simulations with artificial tumors assessed the effects of tumor size and location.ResultsOptimized electrode placements increased tumor electric field intensity by 18%-34% compared with the clinical standard. Coverage-weighted optimizations achieved broader field coverage with minimal reduction in tumor intensity. Smaller and surface-adjacent tumors benefited most from optimization. Extensive randomized placement analyses demonstrated the superior performance of the optimized configurations. Artificial tumor models showed consistent improvements across a range of tumor locations and sizes.ConclusionsPersonalized optimization of TTFields electrode placement improved simulated electric field metrics within tumors and adjacent brain regions compared with the current clinical planning approach. These findings support the potential of patient-specific computational planning and the future development of adaptive, automated TTFields planning strategies. The clinical significance of the observed field improvements remains to be established in prospective studies.

Zinc-nickel sulfide (ZnNiS) nanostructures were synthesized via a simple ball-milling process followed by low-temperature annealing and investigated exclusively as a surface-modifying layer for electrochemical methanol sensing on conductive substrates. Structural characterization using X-ray diffraction, Fourier-transform infrared spectroscopy, scanning and transmission electron microscopy confirmed the formation of nanocrystals with a mixed orthorhombic-trigonal phase and particle sizes in the range of 50-150 nm. BET analysis revealed a mesoporous morphology with a high specific surface area, while thermal analysis confirmed stability up to 550 °C, supporting their suitability for electrochemical applications. Electrochemical measurements using cyclic voltammetry and linear sweep voltammetry demonstrated that methanol oxidation is primarily driven by the nickel substrate, with ZnNiS acting as a nanostructured catalytic modifier that enhances active surface sites and facilitates charge transfer processes. The optimized electrode configuration exhibited sensitivities of 62.785 µA mM-1 on Ni-based electrodes and 3.8214 µA mM-1 on stainless steel, confirming the dominant role of the substrate in governing the overall response. Kinetic analysis indicated pseudo-second-order adsorption behavior, consistent with chemisorption-controlled electrooxidation of methanol. Overall, the study highlights the synergistic interaction between ZnNiS nanostructures and the Ni substrate, leading to improved electrochemical sensing performance for cost-effective methanol detection.

Identifying optimal conditions for transcutaneous spinal cord stimulation (tSCS), such as electrode configuration, is essential for clinical translation, particularly as this promising neuromodulation therapy expands to include diverse neurological populations. However, before clinical application, it is important to understand how different configurations affect dosage and muscle recruitment. We define dosage as the percentage of the current needed to elicit a motor response (the resting motor threshold, or RMT) of the current value tolerated during walking when stimulation is delivered continuously. Another consideration is whether electrode configurations can selectively recruit specific muscles, potentially guiding tSCS protocols to prioritize the muscles most critical for functional improvement. This study tested five electrode configurations in individuals with chronic stroke: one round electrode at T11-T12 vertebrae, one round electrode at L1-L2, two separate round electrodes at T11-T12 and L1-L2 from separate current channels, two separate round electrodes at T11-T12 and L1-L2 from the same current channel, and a rectangular electrode spanning T11-T12 and L1-L2. No single electrode configuration clearly outperformed others in terms of tolerated dosage, with most supporting stimulation near 50% of RMT except the two-channel setup with separate current channels, which showed lower dosage (∼35% RMT). Additionally, muscle selectivity did not significantly differ across configurations. These findings inform stimulation dosage feasibility for future tSCS protocols using different electrode configurations and the need for future studies to evaluate whether current dosage levels are adequate to induce meaningful neuromodulation and clinical benefits in the stroke population.NEW & NOTEWORTHY This is the first study to examine how electrode configuration influences stimulation comfort in transcutaneous spinal cord stimulation (tSCS) relative to resting motor threshold (RMT) in individuals with stroke. Across five configurations, most were tolerated at ∼50% RMT, whereas a two-channel setup reduced tolerance (∼35%). Muscle selectivity did not differ significantly among configurations. These findings establish critical feasibility benchmarks for electrode placement in future tSCS protocols for stroke rehabilitation.

This study investigates the thermal risks associated with electrosurgical units (ESUs) in patients with metallic orthopedic implants. Using a combination of phantom-based experiments and computational simulations, we evaluated the effects of implant presence and electrode configuration on localized heating. Gel phantom experiments were conducted under three conditions: without implants, with a titanium rod, and with a metallic plate positioned between ESU electrodes. Voltage and temperature changes were recorded across ESU power settings at 20W, 30W, and 40W. These results were validated using COMSOL simulations. To assess clinical relevance, human body simulations with the Duke model in Sim4Life were performed at 40W, 80W, and 120W, evaluating the impact of implant proximity and dispersive electrode placement. Results showed strong agreement between experimental and simulation data. Significant temperature increases were observed near implants, especially at higher power settings or with short distance between implant and ESU electrode, the maximum temperature increase could achieve 11.6 ℃ at the implant device when the device is 3 cm away from active electrode. This is about 4 times higher than that from the scenario without any implants. ESU electrode placement can also influence heating patterns. These findings highlight the importance of surgical configuration and implant positioning in minimizing thermal risks during electrosurgical procedures.

Contact electrification has been extensively investigated and harnessed, yet quantifying the triboelectrification capacity of liquid phase materials remains elusive due to their non-fixed shape and complex flow dynamics. Here, we report a novel gas-regulated flow strategy to stabilize liquid columns, effectively decoupling fluid kinetics from electrification processes. By optimizing material selection, electrode configurations, and flow regimes, we established a standardized triboelectric series encompassing 50 diverse liquids, including organic solvents and ionic solutions. Our results reveal that liquid-phase triboelectrification is synergistically governed by molecular functional groups, ionic species, and concentrations. Specifically, hydroxyl groups and dilute ion concentrations promote charge transfer, whereas alkyl groups and excessive ions exert a suppressive effect. This study elucidates that liquid-solid electrification arises from a sophisticated interplay of electron transfer, molecular polarization, ion adsorption/screening, which collectively dictate charge redistribution. By providing a quantitative triboelectric matrix, this work facilitates the design of high-efficiency energy harvesters and safer industrial liquid-handling systems, advancing the fundamental understanding of liquid-interface physics.

Ionic wind and ozone generated by corona discharge have demonstrated considerable potential for applications in nonthermal processing, particularly for low-temperature drying and sterilization of agricultural products. In this study, a corona discharge plasma drying platform was established to evaluate the discharge characteristics of a multi-needle-to-mesh electrode system, as well as the ionic wind and ozone concentration during seed drying. The effects of applied voltage and electrode configuration, including electrode gap (d), mesh aperture (D), and hole spacing (L), on voltage–current (V–I) characteristics, ionic wind velocity, and ozone concentration were systematically investigated. Based on the electrical characteristics, optimal parameters were selected to conduct drying experiments on Capsicum annuum L. seeds, with comparisons made against 50 °C hot-air drying and natural air drying. The findings indicate that positive corona discharge fostered streamer formation at an electrode gap of d = 25 mm. At 15 kV, the positive corona current, ionic wind velocity, and ozone concentration were significantly higher than those under negative polarity. A mesh electrode with an aperture of D = 3 mm and a hole spacing of L = 30 mm was more conducive to generating ionic wind and active species, such as ozone. Drying experiments demonstrate that, under optimal electrical parameters, the initial drying rate of Capsicum annuum L. seeds was 0.11 g/min, approximately 1.8 times that of hot-air drying. This enhancement is primarily attributed to the disruption of the saturated vapor boundary layer on the material surface by the strong ionic wind. In addition, over the same 2-h drying period, the specific energy consumption (SEC) of plasma drying was 18.2 kJ/g, which was substantially lower than that of hot-air drying (33.8 kJ/g). This study confirms the application potential of multi-needle-to-mesh corona discharge technology in the drying of heat-sensitive agricultural products. It provides a theoretical foundation for the design of drying equipment parameters.

This paper investigates the effect of spatial confinement on the electric and propulsive behavior of various quasi-two-dimensional electrode configurations. Ducted electrode systems have indeed recently been investigated in multistage configurations so as to improve electroaerodynamic (EAD) propulsive performance. In this contribution, the effect of dielectric confinement is specifically investigated for parallel emitter–collector systems having a face-to-face distance D while being confined between two parallel dielectric walls separated by a distance 2H. An optimal distance Hopt≈0.6D maximizing the EAD force for every voltage and for each electrode shape (cylindrical or drop-shaped collector) was found, showing better performance than in the corresponding unconfined configuration. Experimental measurements are complemented by numerical simulations that provide consistent results. A collapse of experimental measurements so as to predict the observed current for cylindrical collector configurations is suggested.

Across many oases in semi-arid and arid regions, water availability is steadily declining while soil salinity is increasing at an alarming rate. To address these challenges, the SuLaMo project proposed integrated sustainable land and water management concepts for agriculture, incorporating desalination as a viable source of irrigation water. This study experimentally evaluated a pilot-scale, photovoltaic-driven membrane capacitive deionization (MCDI) system for the desalination of brackish groundwater (TDS = 6.3 mS cm -1 ). The investigation focused on finding practical steps to: (1) evaluate the effect of flow rate on adsorption capacity; (2) optimize the system configuration to maximize water recovery; (3) evaluate the long-term performance and the effect of scaling, electrode configuration and selective ion removal on system efficiency. Additionally, the effect of soil salinisation was monitored during the trials. The results demonstrated the feasibility of MCDI for desalinating low-brackish water and mitigating long-term soil salinization. A trade-off between ion removal efficiency (RE), water recovery (WR), and energy consumption (SEC) was evaluated using a Pareto method. Steps for systematically optimizing the process are suggested. Pilot at low-cleaning operation resulted in optimized values of RE = 45%, WR = 69% and SEC = 2.75 kWh m -3 .m -3 . However, prolonged operation with infrequent cleaning resulted in significant scaling effects, a lower net flow rate and increased SEC. This indicates that frequent cleaning is essential, particularly when treating hard water. Further improvements in electrode adsorption capacity and anti-scaling operational strategies are necessary for the large-scale agricultural application of MCDI. • PV-MCDI was found to be feasible for desalinating low-brackish water in arid environments in Morocco. • Changes in flow demonstrate a trade-off effect between water recovery and specific energy consumption. • Brine disposal remains a critical issue, even with high water recovery rates. • A systematic optimization of pilot-scale MCDI to maximize water recovery is suggested. • The findings highlight the potential of combining MCDI with photovoltaic (PV) systems.

Optimal positioning and size of high-density electrocorticography grids for speech brain-computer interfaces.