Voltage Mode Research Articles

Solely Light‐Induced Integrate‐and‐Fire 1T‐Neuron Operation and Implementation of the McGurk Effect

The increase in global data processing demands cannot be addressed with the limited architecture and processing speeds of existing technologies. Therefore, neuromorphic systems designed to emulate the functionalities of the human brain have emerged as a potential solution to address this issue. In this study, integrate‐and‐fire characteristics are successfully implemented using a single transistor to create a neuron‐like device within neuromorphic systems. The device employs oxide semiconductors as the channel and dielectric materials, ensuring structural stability and complementary metal‐oxide‐semiconductor compatibility. TiO2 is used as the channel material because of its high photoresponsiveness. Further, voltage pulses are applied to the bottom gate to simulate electrical firing in a biological neuron model. Optical firing is achieved by directly exposing the channel to ultraviolet light using only optical stimuli. Moreover, the neuron‐to‐synapse transition behavior that depends on the modulation of the read voltage is observed. This study aims to mimic human brain activity and the McGurk effect is successfully replicated by simulating the integration of auditory and visual stimuli through the combined action of electrical and optical inputs.

A flexible multi-gate organic electrochemical synaptic transistor for image processing

In this study, a P3HT-based multi-gate frequency-dependent synaptic transistor is fabricated, which demonstrates significant advantages in mimicking the transmission characteristics of biological synaptic activities. The proposed device simulates outputs related to frequency and gate voltage modulation. This device can respond differently to inputs ranging from 0.75 to 11.11 Hz, and at the same input frequency, it exhibits different responses by varying the control gate voltage from 0 to −0.8 V. This innovative design can dynamically adjust the cutoff frequency, enhancing edge feature processing in images, thereby significantly improving the recognition accuracy of information in blurry images that can be difficult for humans to distinguish. Our results provide a hardware edge-computing image processing method, overcoming the limitations of traditional single-gate transistors that typically have fixed parameters. The recognition accuracy of information in blurry images preprocessed by this device improved significantly from 80% to 100%. Combined with the multi-gate design, this synaptic device excels not only in edge enhancement and image processing but also offers robust hardware support for future neuromorphic electronics.

Weak Antilocalization and Negative Magnetoresistance of the Gate-Tunable PbTe Thin Films.

We have systematically studied the electromagnetic transport properties of PbTe thin films under gate voltage modulation. The system demonstrates pronounced electron-electron interactions exclusively within the gate voltage range where only hole carriers are present. Furthermore, the Berry phase is utilized to qualitatively elucidate the transition between weak antilocalization (WAL) and weak localization (WL) through the regulation of gate voltage and temperature. Using the three-resistor model, we have effectively explained the correlation between the characteristic temperature of the R-T curve, the coexistence of electron-hole carriers, and the nonmonotonic temperature dependence of negative magnetoresistance (NMR), consistently indicating that complex magnetotransport phenomena are caused by microscopic disorder. Our research findings open up new avenues for exploring and manipulating the magnetotransport properties of PbTe thin films.

Dual Ionic Signal Detection: Modulation of Surface Charge of Nanofluidic Iontronics by Dual-Split Gate Voltages.

Nanofluidic iontronics, including the field-effect ionic diode (FE-ID) and field-effect ionic transistor (FE-IT), represent emerging nanofluidic logic devices that have been employed in sensitive analyses. Making analyte recognitions in predefined nanofluidic devices has been verified to improve the sensitivity and selectivity using a single ionic signal, such as ionic current amplification, rectification, and Coulomb blockade. However, the detection of analytes in complex systems generally necessitates more diverse signals beyond just ionic currents. Here, we demonstrated that dual ionic signals, steady ionic switching ratio, and transient response time (ts) act as detection signals modulated by dual-split gate voltages along the nanochannel for the detection of charged analytes. With an increase in gate voltage, the switching ratio decreases in both FE-ID and FE-IT, whereas the response time exhibits an exponential increase specifically in the FE-ID. Moreover, the response time shows no significant correlation with the external transmembrane voltage in the FE-IT. These results contribute to the optimization of reconfigurable iontronics through gate voltage modulation, providing a theoretical foundation for multiple ionic signal detection.

Improvement of the Wear and Corrosion Resistance of CrSiN Films on ZE52 Magnesium Alloy Through the DC Magnetron Sputtering Process

The utilization of magnesium alloys as lightweight structural materials is becoming increasingly prevalent, particularly within the fields of electronics, automotive engineering, and defense. These alloys display high specific strength and excellent heat dissipation properties. The magnesium–zinc–rare earth alloy ZE52 displays superior formability and strength-ductility when compared to conventional magnesium alloys. A CrSiN film was deposited on the surface using a sputtering technique with the objective of enhancing wear and corrosion resistance for industrial applications. A CrSi buffer layer was deposited onto the ZE52 substrate prior to the deposition of the CrSiN film, with the objective of enhancing the adhesion between the two materials. The sputtering process for CrSiN films entailed the modulation of the substrate bias voltage. The CrSiN films exhibited a nanocomposite structure comprising CrN nanocrystallites embedded within an amorphous Si3N4, which resulted in enhanced hardness. Upon adjusting the bias voltage, improvements in mechanical properties were observed, with the film hardness and Young’s modulus increasing to 16.5 GPa and 187.4 GPa, respectively. Among the various CrSiN coatings under investigation, the ZE52 alloy that was coated with a CrSiN film deposited at a bias voltage of −50 V and a substrate temperature of 250 °C demonstrated the most favorable performance, exhibiting the lowest wear rate and superior corrosion resistance. In the tungsten carbide wear test with a loading of 4 N, the coating exhibited the lowest wear rate, at 2.2 × 10−6 mm3·m−1·N−1. Furthermore, the coating demonstrated remarkable corrosion resistance in a 3.5% NaCl solution, displaying a corrosion current density of 1.23 μA·cm−2 and a polarization resistance of 1271.4 Ω·cm−2.

A novel pulse-current waveform circuit for low-energy consumption and low-noise transcranial magnetic stimulation.

Transcranial magnetic stimulation (TMS) is widely used for the noninvasive activation of neurons in the human brain. It utilizes a pulsed magnetic field to induce electric pulses that act on the central nervous system, altering the membrane potential of nerve cells in the cerebral cortex to treat certain mental diseases. However, the effectiveness of TMS can be compromised by significant heat generation and the clicking noise produced by the pulse in the TMS coil. This study proposes a novel, non-resonant, high-frequency switching design controlled by high-frequency pulse-width modulation (PWM) voltage excitation to achieve ideal pulse-current waveforms that minimize both clicking noise and heat generation from the TMS coil. First, a particle swarm optimization algorithm was used to optimize the pulse-current waveform, minimizing both the resistance loss and clicking noise (vibration energy) generated by the TMS coils. Next, the pulse-current waveform was modeled based on the principles of programmable transcranial magnetic stimulation circuits. The relationships between the parameters of the pulse-current waveform, vibration energy, and ohmic resistance loss in the TMS coil were explored, ensuring the necessary depolarization of the nerve membrane potential. Finally, four insulated-gate bipolar transistors, controlled by a series of PWM pulse sequences, generated the desired pulse-current duration and direction in the H-bridge circuit. The duration and slope of the rising and falling segments of the current waveform were adjusted by the PWM pulse duration. The optimized current waveform, represented by three segmented functions, reduces heat loss and noise while inducing a greater change in neural membrane potential compared with those obtained with conventional symmetric waveforms. Spectral analysis further confirmed that the noise spectrum of the optimized current waveform, particularly the peak spectrum, is significantly lower than that of the conventional triangular symmetric waveform. The study provide a method and new ideas for low energy consumption and low-noise transcranial magnetic stimulation by using TMS circuit design techniques as well as waveform optimization.

Improving electron injection of organic light-emitting transistors via interface layer design.

Ambipolar transport is crucial for constructing high performance organic light-emitting transistors (OLETs), but the ambipolar feature is usually not exhibited due to ineffective electron injection especially in symmetric device geometry. Herein, we show that electron injection could be greatly enhanced through the judicious design of an organic interface layer of 3,7-di(2-naphthyl)dibenzothiophene S,S-dioxide (DNaDBSO) which shows an interfacial dipole effect upon contact with a metal electrode, especially an Au electrode. When incorporating a DNaDBSO film beneath Au electrodes, the electron injection and mobility were significantly enhanced in 2,6-diphenylanthracene-based OLETs, and thus ambipolar transport (μmaxh: 2.17 cm2 V-1 s-1, μmaxe: 0.053 cm2 V-1 s-1) was effortlessly obtained. Furthermore, the shift of the electroluminescent region was obviously observed upon modulation of gate voltage, which demonstrates efficient electron injection and intrinsic ambipolar transporting properties in devices. This study provides a new avenue for regulating the interface in electroluminescent devices towards high performance simple-structured OLETs in applications.

Analytical computation of arm inductor for minimizing MMC circulating current using passive method

The study of circulating currents in modular multilevel converters is vital for improving their efficiency and reliability. The circulating current may arise from capacitor voltage unbalancing, modulation imperfections, load variations, and transient conditions. Such currents typically induce distortions in arm currents, exhibiting second-order harmonics that lead to power losses and negatively impact the ratings of converter components as well as the amplitudes of capacitor voltage ripples. Despite ongoing research, effective strategies to mitigate circulating currents are limited. This paper aims to systematically address this issue by selecting key design parameters specifically arm inductance and capacitor values, to suppress circulating currents. The methodology incorporates harmonic analysis and instantaneous power theory to derive expressions for arm inductance. Initial modelling includes common mode and differential mode analyses, leading to an examination of harmonic content. Analysis reveals that the selection of the arm inductor value is mainly influenced by the second-order harmonic component, whereas the capacitor value is determined by the fundamental harmonic component. By adopting this methodology, the boundary limit for arm inductor selection can be determined. This article proposes a novel expression for arm inductor selection. The proposed expression mainly depends on factors such as load, submodule capacitor voltages, submodule capacitor, and differential current. By selecting an appropriate inductor value based on converter-rated parameters, circulating current within the system can be effectively suppressed. The methodology offers a practical framework for arm inductor selection. Simulation results validation shows strong alignment with analytical results with the error margin of less than 1%, hereby the MMC parameter can be determined with better accuracy through analytic method.

A TSF Control Strategy with Zero Voltage Modulation in Interval Segmented for Permanent Magnet-assisted Switched Reluctance Motor

A TSF Control Strategy with Zero Voltage Modulation in Interval Segmented for Permanent Magnet-assisted Switched Reluctance Motor

Study of the influence of temperature on the opticalscheme of a resonator fiber-optic gyroscope

The article presents a study of the temperature effect on the optical circuit of a resonator fiberoptic gyroscope (RFOG), as well as a study of the temperature effect on the half-wave voltage of the phase modulator, the effect on the spectra and power of the superluminescent diode, and the output amplitude-frequency characteristic of the fiber-optic ring resonator. The results of the study showed that in the temperature range from -30 to +50 °C has a significant effect on the parameters of the optical circuit of the RFOG. This study is an important stage in the development of the RFOG, indicating which parameters must be especially carefully monitored during further development of the sensor to ensure the temperature stability of the device.

Bias Selectable Dual Band Detectors Based on Vertically Aligned In2S3‐coated ZnO Nanorod Arrays Grown on p‐GaN

Herein, we report vertically aligned In2S3 coated ZnO nanotube arrays deposited on p‐GaN substrate by wet chemical method. The fabricated device based on In2S3/ZnO/p‐GaN heterostucture structure displays an enhanced photoresponse with self‐driven operation. The device based on ZnO/p‐GaN structure coupling with In2S3 nanoparticles exhibits bias selectable photodetection by detecting UV and UV/visible light through bias voltage modulation. This strategy can benefit to fabricate broadband photodetector based on ZnO/GaN structure.

The influence of welding modes on metallic structures processed through WAAM

Abstract Wire arc additive manufacturing (WAAM) has emerged as a versatile and cost-effective technique for fabricating complex, large-scale components with enhanced material flexibility. The bead profile, like width, height, and penetration, is critical in WAAM fabrication, influencing the quality and performance of the final component. Consistent and precise profiles are essential for accurate layering and material deposition in complex 3D structures. Various parameters, such as current, voltage, deposition rate, interpass temperature, and welding mode, impact deposit quality in WAAM. This study focuses on implementing a controlled heat input deposition approach, utilizing various welding modes: Control Weld (classic MIG/MAG), Speed Weld (voltage-controlled pulsed arc), Vari Weld (current-controlled pulsed arc), Rapid Weld (high-capacity spray arc), Root Weld (energy-reduced short arc), and Fine Weld (energy-reduced, current-controlled short arc). The study scrutinizes the impact of altering the welding mode on bead profile, bead quality, macroscopic morphology, microstructure, and mechanical properties in single-bead WAAM structures.

PID-based Closed-Loop Voltage Mode Control for Addressing Non-Idealities in Ćuk Converters for Renewable Energy Application

PID-based Closed-Loop Voltage Mode Control for Addressing Non-Idealities in Ćuk Converters for Renewable Energy Application

Design and Simulation of Single Input Double Output Coupled Inductor Boost Converter with Bisection Method for Independent Home Application

This paper proposed a converter design that functions as a voltage booster, increasing the input voltage while supplying two load outputs from a single voltage input using only one switch. Known as a single input double output (SIDO) converter, it aims to enhance power efficieny. The bisection method is employed as an output voltage controller through pulse width modulation (PWM) to achieve an optimal voltage value, adjusted to meet the load requirements. The loads used for independent home applications include a 72 V/12 Ah battery and a 24 V/22 W water circulation pump. The output of the high voltage level acts as a battery charger while the output of the low voltage level serves as an energy supply for the water cir-culation pump. The two loads were chosen because they are widely used, aligning with the goal of realizing independent home applications. The simulation test results showed that the voltage output for battery charging in constant voltage mode was 80.6 V, with an error of 0.0515%, and the voltage output for the water circulation pump was 24 V, with an error of 0.33%.

An efficient design methodology for a tri-state multiplier circuit in carbon nanotube technology

Abstract This study delves into the computational aspects of ternary logic and the use of carbon nanotube field-effect transistors (CNTFETs) to develop an energy-efficient and robust ternary multiplier (TMUL). Leveraging the exceptional qualities of CNTFETs, such as balanced electron and hole mobility and easy modulation of threshold voltage, the research aims to achieve the desired designs. An innovative design method is employed, recommending a reduced count of logic gates for achieving necessary logic levels. These gates are then utilized to manage the activation and deactivation of the primary transistors within the TMUL cell to convey the intended logics to the outputs. Moreover, the suggested design is focused on a single-V DD , enhancing compatibility with the goals of a multi-valued logic platform. The proposed circuit is validated using Synopsis HSPICE simulator and Stanford’s standard 32-nm CNTFET model file. Comparative analysis with existing TMUL designs demonstrates a 25.43% decrease in average power consumption, a 42.24% reduction in power-delay product (PDP), and a 24.69% decrease in energy-delay product (EDP). The design undergoes thorough simulations under various conditions including load variations and process, voltage, and temperature (PVT) fluctuations to confirm its reliability and robustness.

Vibration characteristic, quality factor and sensitivity analysis of a resonant micro-gyroscope based on the blue-sideband parameter modulation

In this paper, we design a nonlinear resonant micro-gyroscope based on the blue-sideband parameter modulation (BSPM), and Coriolis force acts in the axial direction of the resonant beam in the form of a twice-frequency parameter excitation. Considering the geometrical nonlinearity of the micro-beam, the dynamic equations of the resonant beam are derived and discretized according to Hamilton principle and Galerkin method. The discretized equations are subjected to perturbation analysis by using the multi-scale method, and the quality factors of the resonant beams are calculated by the half-power bandwidth method. Moreover, the sensitivity of micro-gyroscope is characterized by the amplitude ratio changes before and after the bifurcation of the nonlinear resonant beam. We conducted a detailed study on the effects of Coriolis force dynamic input, and BSPM on the amplitude-frequency response of resonant beam and the sensitivity of micro-gyroscope. The results indicate that when Coriolis force acts on the resonant beam in the form of a twice-frequency parameter excitation, it not only causes the resonant frequency of the micro-beam to shift but also significantly increases the amplitude of the resonant beam. The addition of BSPM significantly improves the quality factor of the resonant beam and enhances the signal-to-noise ratio. Under nonlinear conditions, when the modulation voltage is sufficiently large, the amplitude-frequency response of resonant beam exhibits two unstable regions near the resonant frequency. Although BSPM reduces the amplitude ratio sensitivity, there is still a 60 times improvement over conventional frequency shift sensitivity. Furthermore, BSPM reduces the nonlinearity degree of the amplitude ratio sensitivity by 64%, which is important for the design and fabrication of high-sensitivity resonant micro-gyroscope.

Multioutput Isolated Power Supply With Selectable Constant Voltage and Constant Current Modes Based on Magnetic Coupling Resonance

Multioutput Isolated Power Supply With Selectable Constant Voltage and Constant Current Modes Based on Magnetic Coupling Resonance

Impact of patient habitus and acquisition protocol on iodine quantification in dual-source photon-counting computed tomography.

Evaluation of iodine quantification accuracy with varying iterative reconstruction level, patient habitus, and acquisition mode on a first-generation dual-source photon-counting computed tomography (PCCT) system. A multi-energy CT phantom with and without its extension ring equipped with various iodine inserts (0.2 to 15.0mg/ml) was scanned over a range of radiation dose levels ( 0.5 to 15.0mGy) using two tube voltages (120, 140kVp) and two different source modes (single-, dual-source). To assess the agreement between nominal and measured iodine concentrations, iodine density maps at different iterative reconstruction levels were utilized to calculate root mean square error (RMSE) and generate Bland-Altman plots by grouping radiation dose levels (ultra-low: ; low: 1.5 to 5; medium: 5 to 15mGy) and iodine concentrations (low: ; high: 5 to 15mg/mL). Overall, quantification of iodine concentrations was accurate and reliable even at ultra-low radiation dose levels. RMSE ranged from 0.25 to 0.37, 0.20 to 0.38, and 0.25 to 0.37mg/ml for ultra-low, low, and medium radiation dose levels, respectively. Similarly, RMSE was stable at 0.31, 0.28, 0.33, and 0.30mg/ml for tube voltage and source mode combinations. Ultimately, the accuracy of iodine quantification was higher for the phantom without an extension ring (RMSE 0.21mg/mL) and did not vary across different levels of iterative reconstruction. The first-generation PCCT allows for accurate iodine quantification over a wide range of iodine concentrations and radiation dose levels. Stable accuracy across iterative reconstruction levels may allow further radiation exposure reductions without affecting quantitative results.

Autonomous Street Lighting System based on Solar Energy and LEDs

This paper introduces a solar-powered autonomous street lighting system designed primarily for areas without access to the grid, such as rural roads and intersections. It utilizes solar panels as the primary energy source, with batteries serving as backup, and employs light-emitting diodes (LEDs) for illumination. The proposed system is optimized for efficiency by employing direct current (DC) power at all stages. To replace a 70W high-pressure sodium (HPS) lamp, an LED fixture design is discussed, considering human scotopic vision. Experimental outcomes for the LED driver and battery charger are provided, demonstrating features such as maximum power point tracking (MPPT), constant current, and constant voltage modes. The system ensures MPPT under varying solar irradiance and temperature conditions by analyzing the battery charger input impedance.

Gate-tunable high tunneling magnetoresistance induced by hybrid interface states in Ni-electrode single-molecule junctions

Based on the density functional theory and non-equilibrium Green's function method, the modulation effects of gate voltage on the spin transport properties of Ni/triphenylene/Ni single-molecule junctions are investigated. The plane-, platform-, and tip-shaped electrode configurations are considered in the calculations. The numerical results show that the electrode configuration and gate voltage significantly influence the hybrid interface states (HIS) and further the spin transport properties of the molecular junctions. The molecular junctions with plane- and platform-shaped electrode configurations show weak spin polarization (SP) and tunneling magnetoresistance (TMR). Still, they exhibit excellent field effect transistor behaviors with the modulation of the gate voltage. Due to the delocalized spin-down HIS located at the Fermi level, the molecular junction with tip-shaped electrode configuration presents high and controllable SP and TMR behaviors through the gate voltage modulation. The calculations demonstrate that high spin-polarized HIS located at the Fermi level are extremely significant for the generation of excellent spin transport properties in molecular junctions composed of non-magnetic molecule and magnetic electrodes.