Deep brain stimulation (DBS) is effective for treating neurological and psychiatric disorders. However, its tethered configuration, invasiveness, and limited tissue compatibility motivate wireless, minimally invasive alternatives. Here, we develop an in situ-gelled injectable conductive hydrogel (ICH), enabling wireless neuromodulation via electric-field localization under volume conduction. The ICH forms in vivo through bio-catalyzed polymerization and electrostatic self-assembly, yielding a stable, highly conductive, tissue-soft, and biocompatible network. Under high-frequency capacitive coupling, impedance difference between the ICH and surrounding brain tissue induces interfacial polarization and charge accumulation, locally concentrating the electric field to activate nearby neurons. This mechanism is supported by enhanced calcium signaling, increased c-Fos expression, and electrophysiological evidence of balanced basal ganglia-cortical activity. In a Parkinson's disease rat model, ICH-mediated stimulation improved locomotor behavior, preserved dopaminergic neurons, and restored functional connectivity and structural integrity as revealed by fMRI. This injectable hydrogel bioelectronics provides a platform for minimally invasive, wireless neuromodulation therapies.

Improving the efficiency of tumor treating fields delivery in tumor cell proliferation inhibition through conductive electrodes.

Suppressing the Capacitive Coupling by Adjusting the Precharge Biasing Scheme in a Two-Transistor Dynamic Random-Access Memory Operation

Dispersive readout, the standard method for measuring superconducting qubits, is limited by multiphoton qubit-resonator processes arising even at moderate drive powers. These processes degrade performance, causing dispersive readout to lag behind single- and two-qubit gates in both speed and fidelity. In this Letter, we propose a novel readout method, termed junction readout. Junction readout leverages the nonperturbative cross-Kerr interaction resulting from coupling a qubit and a resonator via a Josephson junction. Furthermore, by adding a capacitive coupling in parallel to the junction, Purcell decay induced by the exchange coupling can be suppressed. We also show that junction readout is more robust against deleterious multiphoton processes, and offers greater flexibility for resonator frequency allocation. Crucially, junction readout achieves superior performance compared to dispersive readout while maintaining similar hardware overhead. Numerical simulations show that junction readout can achieve fidelity exceeding 99.99% in under 30ns of integration time, making it a promising alternative for superconducting qubit readout with current hardware.

In this paper, we propose a new gas nanosensor based on a dual-gate Schottky barrier carbon nanotube field-effect transistor (DG SB-CNTFET) endowed with an all-terminal gas-sensitive configuration, investigated through full quantum-mechanical simulations. The numerical modeling is performed using the non-equilibrium green's function formalism combined with a pz-orbital nearest-neighbor tight-binding approach to describe quantum transport in SB CNTFETs. Full three-dimensional (3D) electrostatics is incorporated by self-consistently solving the Poisson equation. The sensing principle relies on gas-induced variations in the metal work function at all terminals. The 3D quantum simulation study covers transfer characteristics, potential profiles, charge density distributions, transmission coefficients, and sensitivity in both current-mode and pseudo-threshold voltage-shift mode. Four device configurations are investigated: (i) only the source terminal is sensitive, (ii) both source and drain are sensitive, (iii) source, drain, and top-gate are sensitive, and (iv) all terminals, including the back-control gate, are sensitive. The potential for sensitivity enhancement through coupling capacitance engineering is also examined. Results show that the all-terminal gas-sensitive configuration yields a substantial improvement in the constant-current gate voltage shift, enabling the detection of extremely low gas pressures. These findings establish the proposed DG SB-CNTFET-based nanosensor as a strong candidate for next-generation ultra-sensitive gas detection systems, where compact size, low power consumption, and exceptional sensitivity are critical requirements.

This paper presents a high-sensitivity microwave sensor based on a modified Complementary Split Ring Resonator (CSRR) architecture, integrated with inductive stubs, for non-invasive blood glucose monitoring. The proposed sensor is designed to enhance the electric field localization and coupling efficiency by introducing inductive elements that strengthen the perturbation effect caused by glucose concentration changes in the blood. Numerical simulations were conducted using a multilayer finger model to evaluate the sensor’s performance under various glucose levels ranging from 0 to 500 mg/dL. The modified sensor exhibits dual-resonance characteristics and outperforms the conventional CSRR in both frequency and amplitude sensitivity. At an optimized stub gap of 2 mm, which effectively minimizes the capacitive coupling effect of the transmission line and thereby improves the quality factor, the sensor achieves a frequency shift sensitivity of 0.086 MHz/mg/dL and an amplitude sensitivity of 0.02 dB/mg/dL, compared to 0.032 MHz/mg/dL and 0.0116 dB/mg/dL observed in the standard CSRR structure. This confirms a significant enhancement in sensing performance and field confinement due to the optimized inductive loading. These results represent significant enhancements of approximately 168% and 72%, respectively. With its compact design, increased sensitivity, and potential for wearable implementation, the proposed sensor offers a promising platform for continuous, real-time, and non-invasive glucose monitoring in biomedical applications.

ABSTRACT This article proposes a dual‐polarization broadband frequency selective rasorber (FSR) based on a composite metasurface structure, achieving ultra‐wide absorption bands on both sides of the transmission band. The vertically stacked configuration consists of a lossy layer and a frequency selective surface (FSS) layer. The top lossy layer uses compact electric resonators with coupling capacitors, while the lower FSS layer features a Jerusalem cross‐slot structure, both designed to enhance absorption bandwidth. To elucidate the underlying physical mechanism, an accurate equivalent circuit model (ECM) is established, combined with surface current distribution analysis to interpret the absorption behavior. Simulation results show that the proposed FSR achieves a dB reflection band over 3.68–16.94 GHz with a fractional bandwidth of 128.6%, featuring a minimum insertion loss of 0.3 dB at 10.3 GHz. The design achieves the widest low‐reflection bandwidth among reported two‐layer FSRs without increasing structural complexity. A prototype was fabricated and measured, showing reasonable agreement with simulations. The proposed FSR exhibits potential in broadband stealth radomes and anti‐interference systems.

Abstract Antenna instruments deployed in space are known to be sensitive to dust impacts, and the detected signals can be used to characterize the dust populations within the solar system. Recently, an electrostatic model describing how transient impact plasmas generate characteristic signals measured by antennas was presented. This first-principles model considers the capacitive coupling between the elements of the spacecraft (SC)–antenna system and calculates the collected and induced charging from the expanding impact plasma. Here, the model is updated to include the angular and velocity distributions of the ions in the impact plasma. The relevant parameters of the impact plasma are obtained from laboratory measurements using a dust accelerator. These parameters are further refined by matching the updated electrostatic model to antenna signals collected in the laboratory using a simple model SC. The angular distribution of ion expansion is best described by a cosine distribution, cos β θ , with β = 1. The velocity distribution considers heavy-, medium-, and low-mass ions present in the impact plasma with corresponding velocities of 3.8, 14, and 36.7 km s −1 for high speed dust impacts. The updated electrostatic model provides excellent agreement with antenna measurements collected in the laboratory and can be used as a basis for analysis and precise interpretation of dust impact data collected by antenna instruments on various space missions.

This study proposes a hybrid wireless power transfer (WPT) coupler that integrates a Double-D (DD) coil and a Split Capacitive Plate (SCP) for unmanned aerial vehicle (UAV) near-field charging stations. The proposed structure arranges the DD coil and SCP orthogonally in a stacked configuration, enabling simultaneous utilization of both magnetic and electric field coupling paths. The equivalent circuit is composed of integrated inductive and capacitive coupling branches. The overall network is divided into subcircuits to define transmission matrices, which are then converted into a 2 × 2 S-parameter matrix. To verify the analytical model, the equivalent circuit results were compared with 3D full-wave simulation outcomes, showing a discrepancy of less than 8%, which is acceptable considering circuit simplification and parasitic effects. Furthermore, simulation results under positional and rotational misalignment conditions confirm that the proposed coupler maintains stable power transfer efficiency even beyond a 25% offset range. These results demonstrate that the complementary coupling mechanism, where one dominant coupling mode compensates for the attenuation of the other, operates effectively under misalignment. Consequently, the proposed hybrid coupler provides a promising alternative for enhancing misalignment tolerance in UAV near-field wireless charging systems.

Wireless Electric Vehicle Charging (WEVC) systems have become a game-changing remedy aimed at enhancing the convenience, safety, and efficiency of electric vehicle (EV) charging. Unlike traditional plug-in systems, with WEVC, physical connectors are no longer necessary by utilizing wireless energy transfer technologies, such as resonant electromagnetic techniques, capacitive coupling, and inductive coupling. These technologies enable seamless power delivery from charging pads to onboard vehicle receivers, allowing EVs to be charged either in stationary or dynamic conditions without manual intervention. This review provides a comprehensive examination of recent advancements in WEVC systems, focusing on improvements in energy efficiency, power transfer capabilities, and adaptability with existing transportation infrastructure. Key innovations in coil design, alignment mechanisms, and power electronics have significantly improved the reliability and performance of these systems. Despite these advancements, several technical and economic challenges persist, including misalignment losses, electromagnetic interference, high implementation costs, and limitations in standardization and interoperability. The review further discusses the regulatory and safety factors that need to be taken into account in order to guarantee the secure implementation of WEVC technology, especially in urban and high-traffic environments. Additionally, the integration of WEVC with smart grid systems and renewable energy sources holds great promise for enhancing grid resilience and enabling energy-efficient transportation networks. The synergy between wireless charging and intelligent traffic management could further promote the development of sustainable, connected, and automated mobility solutions. By evaluating the current state of research and deployment, this review emphasizes the transformative potential of WEVC in supporting environmentally friendly transportation and contributing to the development of smart cities. Future research directions are proposed to overcome existing limitations and accelerate the widespread adoption of this innovative technology.

Wireless power transfer (WPT) is moving quickly from theory to reality, thanks to a series of smart design improvements. Innovations like the Resonant Regulating Rectifier (3R), multi-frequency operation, optimized coil designs, impedance matching, and adaptive frequency control now make it possible to deliver power efficiently even when conditions aren’t perfect. Whether using capacitive coupling for short distances, magnetic resonance for mid-range, or multi-coil setups for broader coverage, these systems work reliably in many different situations. From tiny medical implants and underwater robots to electric vehicles and high-speed trains, WPT is proving it can power devices both small and large. The strong agreement between lab results and real-world tests shows that these designs aren’t just theoretical anymore, they’re practical, reliable, and ready to power everyday life. They’re compact, efficient, and versatile enough to fit into consumer gadgets, industrial machines, and even transportation systems.

This work investigates the impact of load-dump stress on p-GaN HEMTs under floating gate condition. The experiments show that preconditioning the device with a small load-dump stress (150 V, @td = 100 ms and tr = 8 ms) enhances its robustness against a larger stress (190 V, @td = 100 ms and tr = 8 ms). If a large load-dump stress (≥160 V, @td = 100 ms and tr = 8 ms) is applied directly to the device’s drain, the device will burn out. This occurs because the rapidly changing drain voltage during a load-dump event can generate a capacitive coupling current, leading to transient positive charge accumulation in the gate region. Consequently, the channel under the gate is turned on, allowing a large current to flow through it. The coexistence of high current and high voltage leads to substantial Joule heating within the device, resulting in eventual burnout. When a small load-dump stress is initially applied, the resulting charging of electron traps in the gate region increases the threshold voltage. As a result, the device can withstand a larger load-dump stress before the channel turns on, which explains the device’s enhanced robustness. This work clarifies the failure threshold of p-GaN HEMTs under the load-dump stress, providing key support for improving the devices’ reliability in the practical applications. It can provide a basis for adding necessary protective measures in device circuit design, and clarify the triggering voltage threshold of protective measures to ensure that they can effectively avoid device damage due to the load-dump stress.

ABSTRACT Metal oxide heterostructure assemblies made of ZnO‐Co 3 O 4 core–shell nanowires enable high‐performance self‐powered optoelectronic devices with potential applications in wireless, autonomous, low maintenance medical implants or environmental sensors. Surprisingly, the experimental study of the single core–shell heterostructures forming the assembly was never reported until now. We unveil the transport phenomena occurring in individual ZnO‐Co 3 O 4 core–shell nanowires by engineering ionic liquid‐gated nanotransistors. The nanostructures are isolated on fabrication substrates and equipped with a set of metallic electrodes probing selectively different sections of the nanowire, in three different configurations labelled core–core, shell–shell and core–shell. The observed electrical responses reflect the properties of the ZnO core, the Co shell and the core–shell heterojunction. The ultrahigh capacitive coupling of the ionic liquid to the nanowire and its conformal feature reveal multiple transport regimes in the same nanodevice: the core, the shell and the core–shell heterojunction act as a linear, nonlinear, and rectifying nanoelectronic components, respectively. This work shines light on the transport properties of individual metal oxide nanowire heterostructures employed in self‐powered optoelectronics, suggesting potential applications as multifunctional nanoelectronic components. The methodologies developed in this research set the benchmark for the investigation of nanoscale building blocks of functional semiconductor nanomaterial assemblies for electronic and optoelectronic applications.

Gallium Nitride (GaN) fabricated on an insulated sapphire substrate achieves a higher rated voltage of monolithic power integrated circuits compared to that fabricated on a conductive silicon substrate. In this paper, the effectiveness of isolation approaches considering substrate bias and crosstalk effects between adjacent devices in GaN-on-Sapphire monolithic power integrated circuits is investigated. It is demonstrated that the substrate bias and crosstalk effects between high-side and low-side power devices are effectively suppressed regardless of substrate termination with the implantation isolation approach. Thanks to the ultrathin buffer upon an insulated sapphire substrate, the ion implantation can also isolate the adjacent high-voltage (power) and low-voltage (logic) devices. However, a weak crosstalk effect that is caused by capacitive coupling is still observed between high-voltage devices and low-voltage devices with the implantation approach; the degradation rate is calculated to be up to 3%. Experimental results prove that a shallow trench isolation structure in the implantation region can be adopted to mitigate the crosstalk effects, to further improve the stability of integrated logic circuits and drivers under dynamic high-voltage switching conditions.

Abstract Non-reciprocal devices are key components in both classical and quantum electronics. One approach to realizing passive non-reciprocal microwave devices is through capacitive coupling between external electrodes and materials exhibiting non-reciprocal conductance. In this work, we develop an analytic framework that captures the response of such devices in the presence of dissipation while accounting for the full AC dynamics of the material. Our results yield an effective circuit model that accurately describes the device response in experimentally relevant regimes even at small dissipation levels. Furthermore, our analysis reveals counterpropagating features arising from the intrinsic AC response of the material that could be exploited to dynamically switch the non-reciprocity of the device, opening pathways for tunable non-reciprocal microwave technologies.

Research on high-frequency electrochemical impedance spectroscopy (HF-EIS), focusing on frequency band exceeding 1 MHz, has attracted much attention in recent years. For example, Nakajima et al. reported a spectral change in HF-EIS during the first ten charge and discharge cycles of lithium-ion batteries1. In another study, Ishigaki et al. developed a method to detect metallic lithium deposited on the electrode surface by using the skin effect characteristics of HF-EIS2.However, several issues need to be solved. First, it is necessary to use an experimental apparatus which are not typically used in the field of electrochemistry such as impedance analyzers and network analyzers, since the upper frequency limit of most commercially available potentio/galvanostats with frequency response analyzer is about 1 MHz. Additionally, due to the specifications of most apparatus, coupling capacitors are required to be inserted into the circuit to block the DC current when measuring samples which has an electromotive force. Furthermore, it is important to ensure that the inductive reactance of the wires is sufficiently lower in order to discuss the bulk resistance of the samples.In this study, we developed fixtures for HF-EIS measurements of 2032-type coin cells using a commercially available impedance analyzer and discussed measurement-related challenges.References Nakajima, N. Yamamoto, and Y. Tanaka, Proceeding of the 65th Battery Symposium in Japan, (2022), 3C17. Ishigaki, K. Ishikawa, T. Usuki, H. Kondo, S. Komagata, and T. Sasaki, Nature Communications 14, (2023), 7275.

The development of robust and efficient wireless charging systems is essential for the widespread adoption of electrification in the transport sector, e.g., Electric Vehicles (EVs). Capacitive Wireless Power Transfer (CWPT) has emerged as a promising alternative to inductive methods, offering advantages such as lower cost, lighter structure, and reduced electromagnetic interference. However, the performance of practical CWPT systems, particularly systems employing simple L-type compensation networks, is severely affected by coupling plate misalignment, which causes variations in coupling capacitance. These variations give rise to a pseudo-resonance phenomenon, wherein conventional controllers, such as traditional Sliding Mode Control, mistakenly regulate reactive power to zero at an off-resonant frequency, leading to a drastic collapse in active power transfer. To overcome this limitation, this paper introduces a novel Adaptive Sliding Mode Control (ASMC) framework augmented with an online Recursive Least Squares (RLS) observer for real-time estimation of the time-varying coupling capacitance. The proposed dual-loop control structure integrates an inner adaptive loop that accurately tracks capacitance changes and an outer sliding mode loop that dynamically adjusts the inverter switching frequency to sustain true resonant operation. A rigorous Lyapunov-based stability analysis confirms global convergence and robustness of the closed-loop system. Comprehensive MATLAB/Simulink R2025a simulations validate the proposed approach, demonstrating its capability to maintain zero reactive power and stable 35 kW power transfer with over 95% efficiency under dynamic misalignment conditions of up to 30%. In contrast, a conventional SMC approach experiences severe pseudo-resonant collapse, with output power degrading below 1 kW. These results conclusively highlight the effectiveness and necessity of the proposed ASMC-RLS strategy for achieving robust, misalignment-tolerant CWPT in high-power EV charging applications.

This study investigates the impact of series reactor installation on transient recovery voltage (TRV) and the rate of rise of recovery voltage (RRRV) in the 500 kV Suralaya–Suralaya Baru transmission line within the projected 2030 Java–Madura–Bali (JAMALI) power system. Using data from the PLN RUPTL 2021–2030 [21], the research evaluates how series reactors influence TRV and RRRV during a single line-to-ground or short-line fault occurring 5% from the Suralaya line. Simulations were conducted in DIgSILENT PowerFactory using detailed transmission line modeling that incorporates line coupling and stray capacitance, with model validation performed through power flow and short-circuit comparisons. Two scenarios, before and after the installation of series reactors, were assessed. Prior to installation, TRV was 872.9 kV and RRRV was 2.14 kV/µs, while after installation TRV increased to 922.2 kV and RRRV increased to 11.9 kV/µs. Although the TRV remains within IEEE Std C37.011-2019 limits [11], the RRRV exceeds the standard threshold, indicating the need for mitigation. The study’s novelty lies in developing a detailed Java–Madura–Bali system model in PowerFactory and applying network reduction to improve simulation efficiency. As the effects of series reactors on TRV and RRRV in this system have not been previously examined, the findings provide essential insights for ensuring circuit breaker reliability and supporting future high-voltage system planning.

HighlightsWhat are the main findings?The capacitance behavior of interdigitated electrodes embedded between glass layers for touch sensing applications is accurately analyzed using equivalent circuit models for both touch and no-touch conditions. For a constant sensing area, wider electrode fingers reduce the number of fingers and the baseline capacitance in the no-touch state, resulting in improved touch sensitivity.Touch sensitivity—defined as the relative capacitance difference between touch and no-touch conditions—can be estimated during the electrode design stage by extracting the typical touch coupling capacitance under realistic application conditions. The dominant sensitivity factor is the coupling capacitance from the sensor electrodes through the fingertip and human body to ground, which leads to a lower capacitance measured across the positive and negative sensing electrodes under touch conditions.What is the implication of the main finding?By analyzing and predicting the capacitance value during the sensor design stage, the electrode geometry can be tailored to match the desired sensitivity and measurement range of capacitive sensing chips.Tuning the sensitivity through electrode design and choice of overlay material provides an additional degree of freedom for system optimization, reducing dependence on the sensing chip’s intrinsic capability and threshold settings, and helping to avoid false alarms or missed detections.This paper investigates the capacitance characteristics of a glass-embedded interdigitated capacitive sensor (IDCS) for touch-sensing applications. The study analyzes both baseline (no-touch) and touch-induced capacitance variations through a combination of analytical modeling and experimental validation. A multilayer analytical model is first employed to calculate the baseline capacitance of the proposed structure, followed by experimental measurements for model verification. Subsequently, an equivalent circuit model of the touched state is introduced to represent the interaction between the human fingertip, sensor electrodes, and earth-ground, explaining the observed capacitance reduction during a finger touch. Sensor prototypes with electrode finger widths of 1.4, 2.0, 2.4, and 3.0 mm were fabricated within a 40 × 40 mm2 sensing area. The baseline capacitance decreased from 28.6 pF at 1.4 mm to 12 pF at 3.0 mm electrode finger width, while the capacitance change upon touch ranged from 0.6–0.9 pF. Touch sensitivity for three test persons increased from about 1.7–4.6% at 1.4 mm to 5–7.6% at 3.0 mm electrode finger width. The results confirm that narrower-electrode designs yield higher absolute capacitance, whereas wider electrodes enhance touch sensitivity and provide greater uniformity within the defined sensing area. Overall, the findings validate the proposed IDCS configuration as a practical approach for realizing glass-integrated touch sensors and offer practical guidelines for optimizing electrode geometry in touch-based smart-glass applications.

When the demand for real-time data processing and energy keeps efficiency growing in fields like Advanced Driver-Assistance Systems (ADAS) for electric vehicles, in-memory computing (IMC) is becoming a key technology. The heart of effective IMC is Static Random Access Memory (SRAM). It is widely known for its fast access times and low power requirements. For these reasons, SRAM becomes an ideal choice for FPGA-based systems. This paper delves into optimizing SRAM for IMC by comparing the performance, power efficiency, and stability of three SRAM types: 6T, 8T, and 10 T. Whats more, we introduce the innovative C3SRAM architecture. This technology leverages capacitive coupling to boost computational speed and energy efficiency significantly. Finally, we summarize the CONV-SRAM architecture, tailored for in-memory convolution operations in neural networks. Through these explorations, we provide practical insights into how SRAM can be optimized to meet the demands of high-performance, energy-efficient systems, focusing on applications like autonomous vehicles that require speed and power conservation.