Voltage Research Articles

Reference calibrator of electric voltage within the frequency range 0.1–30.0 mHz

Reference calibrator of electric voltage within the frequency range 0.1–30.0 mHz

Electrical and UV-sensing performance of N-doped-Ba(Ti,Zr,Mo,Hf,Ta)O3-dielectric and ZnSnO-channel-based flexible thin-film transistors

Flexible thin-film transistors (TFTs) based on N-doped Ba(Ti,Zr,Mo,Hf,Ta)O3 dielectric and ZnSnO channel show high electrical and UV-sensing performance. The optimal N-doped Ba(Ti,Zr,Mo,Hf,Ta)O3 compositions with low equivalent oxide thicknesses (≈2 nm) and high-entropy (configurational entropy ≈ 1.59 R) are efficiently determined from a wide composition space (library). The film library is patterned to 450 metal–insulator-metal stacks, revealing dielectric constants ≈ 262–322 and loss (tan δ) ≈ 0.01–0.30 for the N-doped Ba(Ti,Zr,Mo,Hf,Ta)O3 at 1 kHz. The library is further integrated to 63 TFTs, and the promising ones exhibit the remarkable parameters: current on/off ratio of 108, threshold voltage (VT) of 0.02 V, saturation field-effect mobility of ≈76 cm2⋅V−1⋅s−1, and subthreshold swing of 0.062 V dec−1. The devices also exhibit desirable long-term stability for up to five months and perform reliably with small or negligible changes in VT and drain-source current under various gate-bias stress and temperature conditions. Furthermore, the TFT-based ultraviolet (253 nm) detector demonstrates impressive sensitivity (≈ 2 × 106) and responsibility (≈ 1171.9 A W−1). There is no substantial degradation in electrical or sensing characteristics under various levels of deformation. Charge transport in constructed energy band diagrams is used to elucidate the observed remarkable performance.

Field ionization intensity used to measure local pressure in gas flows

A coaxial ion source produces an ion beam via field effect in a gas flow through a coaxial microchannel structure. Measuring the intensity of ion emission under an electric voltage condition reveals the pressure at the tip of the coaxial structure, where ionization occurs. The spatial resolution of the measurements is defined by the volume into which the position of the tip fits, here estimated as a cube with an edge of 10 μm. The pressure at the tip is also obtained analytically as a function of the throughput through the coaxial structure. The theoretical and experimental pressure values reported in the present work are in agreement between them within the geometric uncertainties of the coaxial structure itself.

Physiochemical View of Fuel Jet Impingement and Ignition Upon Contact with a Cylindrical Hot Surface

This study delves into ignition and flame dynamics involving a cylindrical hot surface impact. Previous studies have focused on the flat-wall hot surface interacting with fuel spray, leaving gaps in understanding the effects of cylindrical hot surfaces on fuel-air mixing and ignition. Using high-fidelity large-eddy simulations (LES), this study investigates how fluid elements, upon contacting an electronically activated glow plug structure, exhibit mixing and thermochemical properties. The analysis examines how this type of structure enhances fuel-air mixing and subsequently influences the thermochemistry behavior in conjunction with the fuel-specific combustion behavior. The study includes scenarios with free spray and non-thermal deposit cases to assess their mixing impact, alongside testing five different electric voltage inputs to study the thermally assisted ignition process. Results demonstrate that the cylindrical structure hinders flow, reducing its inertia and increasing flow residence time. Moreover, a significant Coandă effect due to the circular wall structure is identified, potentially serving as a mechanism for enhancing flame-holding. Furthermore, varying the input voltage notably affects ignition timing, revealing a non-monotonic ignition delay pattern with lower voltages. Detailed analysis highlights the critical role of negative temperature coefficient (NTC)-driven low-temperature chemistry (LTC) in the ignition process.

Hf0.4Zr0.6O2 Thickness-Dependent Transfer Characteristics of InxZn1-xOy Channel Ferroelectric FETs.

We investigate how the threshold voltage (VT) is adjusted to create a memory window (MW) in ferroelectric field-effect transistors (FeFETs) composed of ferroelectric Hf0.4Zr0.6O2 and InZnO (In2O3:ZnO = 9:1 wt %). Temperature-dependent polarization measurements reveal a dipole switching in Hf0.4Zr0.6O2. The properties of the n-type InZnO channel are examined by fabricating an oxide transistor with an HfO2 gate dielectric. Upon replacement of HfO2 with Hf0.4Zr0.6O2 in the oxide transistor, a counterclockwise MW is observed. Specifically, as the Hf0.4Zr0.6O2 thickness increases from 16 to 24 nm, the VT of the FeFET after a + gate voltage (VG) sweep remains nearly constant, while the VT after a -VG sweep shifts significantly from -0.9 to 0.5 V. The enlarged MW of approximately 2 V, which is proportional to the Hf0.4Zr0.6O2 thickness in the FeFET, can be explained by considering the balance between VG controllability across the gate stack and the ferroelectric switching of Hf0.4Zr0.6O2.

Electroplasticity constitutive modeling of aluminum alloys based on dislocation density evolution

Electrical current can effectively improve the plasticity of metallic materials. The tensile deformation behavior of Al alloys under the pulsed electrical current assisted quasi-static unidirectional tension (EAT) has been investigated. Materials under the EAT exhibits periodic electro-softening and strain-hardening behaviors, i.e., a ratchet shape mechanical response. However, establishing a constitutive model to accurately predict the ratchet shape mechanical behavior, especially during the EAT interval, and accurately predicting the strain-hardening behavior of materials are critical issues that need to be solved urgently. In this study, based on the Taylor polycrystalline model, thermal activation theory and dislocation density evolution theory, a two-parameter dislocation density electroplasticity constitutive model with forward and reverse dislocation density evolution was developed to describe the periodic coupling effect of the electro-thermal-mechanical fields during EAT. The tensile deformation behaviors of AA 6061-T6 and AA 7075-T6 under the effect of a pulsed electrical current were quantitatively predicted using the proposed constitutive model. The results show that the correlation coefficient between the predicted and experimental results of the constitutive model can reach 0.84–0.99, implying that the proposed constitutive model can accurately predict the complex electroplasticity behavior of Al alloys during EAT.

Enhanced Threshold Voltage and Improved Subthreshold Swing Using NiOX/ITO Reverse Bias Gated Diamond pMOS

An increase in the device performance of diamond‐based p‐type metal–oxide–semiconductor (pMOS) transistors using a combination of p‐type nickel oxide and n‐type indium tin oxide (NiOX/ITO) reverse bias diode as the gate dielectric is reported. Negative threshold voltage pMOS transistors are desirable for digital circuits and power applications for fail‐safe operation. A Schottky gate‐based conventional diamond pMOS transistor suffers from many limitations, including a positive threshold voltage (VT). Herein, it is experimentally demonstrated that NiOX/ITO gate dielectric with Al gate contact circumvents many critical limitations, providing a negative threshold voltage of −1.2 V, improved subthreshold slope of 145 mV dec−1, current ON/OFF ratio >107, and peak gate leakage current reduction >103. An Al/NiOX‐based control gate structure shifts the VTH negative with improvements in crucial device performances. Adding a reverse bias junction through the Al/ITO/NiOX heterointerface with the Al metal gate further improves performance. The measured device characteristics are explained in a common framework of energy band diagram for all the devices.

Numerical investigation into the transition of electrohydrodynamic spraying modes and behaviors

Electrohydrodynamic (EHD) spraying is an interesting phenomenon where the liquid subjected to an electrical stress deforms into an electrified liquid drop, a thin liquid jet, or the so-called Taylor cone, which is also highly complicated owing to its various spraying modes and behaviors. Due to the lack of critical information such as the electric charge density and internal velocity profile, the underlying physics behind the transition of different EHD spraying modes are still not adequately understood. In light of this, we conducted a numerical investigation into the transition of EHD spraying modes and behaviors under the three most important operating parameters including electric voltage, nozzle height, and liquid flow rate. Four typical spraying modes, namely, dripping, cone-jet, multi-jet, and jetting, are observed. From the numerical results, we obtained the voltage distribution in the environment, electric charge density at the liquid–air interface, and velocity profile inside the liquid, which help us to comprehensively analyze and explicate the influences of these three parameters on the transition of spraying modes and behaviors. This eventually leads us to a spraying mode map showing the correlation between the spraying modes and the electric Bond number. To the best of our knowledge, this is the first numerical work focusing on the transition of EHD spraying mode, from which we intend to expand the knowledge of this interesting phenomenon.

Improving spin manipulation in HgTe/CdTe quantum wells via electrical means

We present a theoretical investigation of electron transport properties through a two-dimensional electron gas (2DEG) HgTe/CdTe quantum wells (QWs) heterostructure that incorporate two Rashba-modulated regions. Our study demonstrates that the transmission can be effectively tuned by varying the Rashba spin-orbit coupling (RSOC) strength, Fermi energy, and electrical voltage. Efficient spin-conserving and spin-flip transmission can be achieved by adjusting the RSOC modulation strength. Furthermore, fully spin-polarized spin or current transmission with PZ=±1, as well as complete spin-flip conversion with a rate of Tsf=1 are attained by fine-tuning the amplitudes of the two Rashba modulations using gate voltage or adjusting the RSOC strength. This electrical mechanism provides a convenient approach to electrically manipulate both spin and charge currents, which holds promise for low-power device applications.

Universal all-optical zero-bias logic gates in silicon photonics

Universal all-optical (optical input – optical output) logic gates, realized in a commercial foundry silicon photonics process, are reported. Microring resonator modulator and zero-biased stacked photodiodes are used to create the required optical input-output nonlinear transfer function for optical gate realizations. Several logic gate functions, specifically NOR which is a universal logic gate that can be used to implement any logic, are demonstrated. Logic operation on 10 Mbps data streams is demonstrated using universal optical logic gates without requiring any electrical supply voltage. The total optical power required for one such universal logic gate is 160 µW.

Stress-dependent Magnetization Processes in Co based Amorphous Microwires

Soft magnetic materials with high magnetic susceptibility are sensitive to changing magnetic fields and generate electrical voltage signals whose spectra contain higher harmonics. Magnetic susceptibility and saturation field are largely determined by magnetoelastic interactions in amorphous ferromagnets, respectively, the amplitudes of higher harmonics should depend on external mechanical stresses. In this work, we study the processes of magnetization reversal in amorphous microwires of two compositions: Co71Fe5B11Si10Cr3 and Co66.6Fe4.28B11.51Si14.48Ni1.44Mo1.69 under the action of external tensile stresses. For the first composition, mechanical stresses exceeding a certain limit (more than 350 MPa) lead to the transformation of the magnetic hysteresis from a bistable type to an inclined one. In this case, a sharp change of the harmonic spectrum is observed. In microwires of the second composition with an initially inclined loop, external stresses cause a monotonous increase in the slope of the hysteresis loop (a decrease in susceptibility). In this case, the amplitudes of higher harmonics change significantly at low stresses, less than 100 MPa. The results were obtained by remagnetization of microwire samples using a system of flat coils, which demonstrates the potential of using these materials as wireless sensors of mechanical stresses with remote reading.

Investigation of Innovative High-Response Piezoelectric Actuator Used as Smart Actuator–Sensor System

This paper presents an experimental analysis of a high-response piezoelectric actuator system for the modular design of hydraulic digital fluid control units. It focuses on determining static and dynamic characteristics, forming the basis for developing a smart Industry 4.0 component that incorporates both actuator and sensor function. The design process examines the main challenges, advantages, disadvantages, and working principles to define parameters that impact the actuator’s behaviour and performance. The new piezoelectric actuator system features three piezoelectric stack actuators in series, enabling simultaneous actuation and sensing by applying and measuring the electrical voltage at each piezo element. The experimental setup and test methodology are explained in detail, revealing that the new design, combined with an appropriate open-loop or closed-loop control method, offers superior actuator stroke control, high stroke resolution, and a high-dynamic step response. This paper proposes a concept of a smart piezo actuator system focused on I4.0 and an actuator administration shell, integrated with 5G and RFID technology, which will allow automatic plug-and-play functionality and efficient interconnection, communication, and data transfer between the hydraulic valve and the piezoelectric actuator system.

The impact of XLPE surface defects on electric field and breakdown voltage

During the construction of cable joints, three common defects may occur on the XLPE surface: scratches, moisture exposure, and adhered contaminated particles. To evaluate the impact of these defects on joint performance, this paper establishes a sheet model of XLPE insulation in cable joints to analyze the changes in the electric field under different defects and explore the influence of different defects on the electric field and breakdown voltage. Results of the study reveal that the electric field at the scratch site on XLPE produces severe distortion, being 1.6 times that of non-scratch areas. When exposed to moisture, the more conductive impurities present in the adhered contaminated water on the XLPE surface, the higher the conductivity of the contaminated water, thereby increasing its conductive performance and the electric field strength, which is 1.22–1.4 times that of the non-moist interface. When particles adhere to the XLPE surface, severe distortion occurs at the particle-interface electric field, approximately 1.5 times that of the defect-free interface. Scratches have the most significant impact on the electric field of XLPE insulation. Experimental results also demonstrate that the breakdown voltage without defects is 129.6 kV, while the breakdown voltage with scratch defects is 59.1 kV, moisture defects is 69.7 kV, and particle contamination defects is 59.2 kV, with scratches having the most significant impact on the breakdown voltage of XLPE insulation. These findings provide important insights into the influence of different defects on the insulation performance of cable joints.

Impact of close proximity pulse width modulation switching events on electric machine terminal voltages

AbstractElectric machines form an essential part of a wide range of modern systems. When speed control is required, the use of pulse width modulation‐based inverters is generally the solution of choice. It is also usual to connect the machine to the inverter using a cable. The combination of these three elements produces the potential for voltages which exceed the dc link voltage to occur at the machine terminals. Methods for predicting the terminal voltage exist; however, these methods assume that the pulses applied to the system can be considered as isolated, discrete events. The authors highlight an issue with this assumption. When a switching event occurs, it will cause a voltage disturbance in the unswitched phases of the system due to the mutual coupling between the phases. If a second switching event occurs within a short time of this event the resultant voltage will interact with the previous switching event resulting in a higher terminal voltage than would be the case for an isolated event. This effect can be problematic for insulation design if it is not considered. This issue is demonstrated, with the worst‐case scenarios identified and potential methods of reducing terminal voltage being proposed.

Multicaloric response tuned by electric field in cylindrical MnAs/PZT magnetoelectric composite

The possibility observation of the electric field controlled multicaloric response through quasi-isostatic compression as a result of the converse piezoelectric effect was demonstrated on the cylindrical type magnetoelectric composite MnAs/PZT. It was shown that an electric voltage of 100 V corresponding to an electric field of E ∼0.3 kV/mm applied to the walls of the piezoelectric component PZT of the MnAs/PZT composite contributes to an increase in the maximum adiabatic temperature change by 0.2 K in the temperature range of the magnetostructural phase transition of MnAs ∼317 K at a magnetic field change of 1.8 T. Numerical analysis using the finite element method has shown that an electric field voltage of 100 V is capable of creating a quasi-isostatic mechanical stress in the region inside a cylindrical PZT tube of ∼3 MPa. Moreover, in the region of weak pressures up to 10 MPa, the contribution to the total adiabatic temperature change from piezo-mechanical compression linearly depends on the electrical voltage that can be used for control by magnetic and caloric properties of multicaloric materials.

Design and Simulation of a High-Performance Tunneling Field Effect Transistor-Based Biosensor Using a Heterojunction Electron-Hole Bilayer

Abstract This study introduces a novel dielectrically-modulated heterojunction electron-hole bilayer tunnel field-effect transistor (DM-HEHBTFET) for bio-sensing applications. The device features a Ga0.85Sb0.15As/Ga0.8In0.2As heterojunction and a p-type pocket in the channel, achieving a remarkably low threshold voltage (VT) of 20 mV, an average subthreshold slope (SS) of 5.7 mV/dec, and a leakage current (IOFF) as low as 5 × 10⁻¹¹ A/μm. The staggered bandgap in the heterostructures enhances electric field control, enabling lower gate voltage operation. Furthermore, the strategically positioned nanogap cavities in non-overlapping regions of the top and bottom gates effectively mitigate gate control issues over the channel, ensuring improved device performance. A modified design, the modified DM-HEHBTFET, is also proposed, featuring source and drain regions engineered with Ga0.85Sb0.15As/Ga0.8In0.2As heterojunctions. This design mitigates leakage current and improves the average subthreshold slope (SS). For biomolecules with a dielectric constant of 12, the modified biosensor exhibits a drain current sensitivity (Scurrent) of 2.6e4, average SS=2.7 mV/dec, and IOFF=1e-12 A/μm. The device's performance is assessed by examining steric hindrance and band tailing effects. The modified biosensor outperforms recent DM-TFET biosensors, making it a promising candidate for low-power, high-switching speed bio-sensing.

Equivalence of magnetic flux and energy

Magnetic flux and energy equivalence is the principle that everything that has magnetic flux has an equivalent amount of energy, and vice versa. The main methods used: transformation of natural units, algebra, analogy. The equivalence of magnetic flux and energy, despite its widespread use in describing the principles of physics, has not yet been formulated. This paper presents the formula for this equivalence. This is done based on known measurement systems, parameters and principles of physics. Five examples (Stoney units, Planck units, standard gravitational parameter, Lorentz force, and Ampere force) of the algebraic representation of this principle show its universality. Five examples should justify the universality of the new principle and its use in physics and astrophysics. Using the equivalence of magnetic flux and energy, new physical units of mass and magnetic flux are proposed, each of which is suitable for measuring both mass and magnetic flux. Natural values of electric current and voltage, linear density of electric capacitance and inductance, linear density of magnetic flux, linear density of electric charge, as well as natural units of electric voltage and current, electrical resistance, magnetic flux, electrical capacitance and inductance are also described. The article presents the Einstein field equation (additional magnetic stress–energy–momentum tensor) and a standard astrophysical parameter for refining the orbits of celestial bodies.

Use of RSM desirability approach to optimize WEDM of mild steel

Wire Electrical Discharge Machining (WEDM) is a non-traditional material removal process commonly used for precision machining of hard materials such as super alloys, ceramics, carbide, and composite materials. Optimization of process parameters is critical for improving machining efficiency and achieving the desired surface quality. Response Surface Methodology (RSM) systematically optimizes process parameters and investigates their impact on machining performance. WEDM control parameters such as pulse ON Time (TON) (50–60 μs), pulse OFF Time (TOFF) (25–34 μs), gap voltage (VG) (25–250 V), peak current (IP) (1–6 A), and dielectric flow rate (Df) (1–3 LPM) are optimized to reduce surface roughness (SR) and taper angle (TA) while increasing material removal rate (MRR) during the machining of Mild Steel. The optimal parameters are TON as 53 μs, TOFF as 28 μs, IP as 2.65 A, VG as 185 V, and Df as 1.5 LPM. The experimental findings are presented to demonstrate the usefulness of the proposed strategy in optimizing WEDM control parameters. The validation test was conducted under optimal conditions and the results were reported. The manufacturing industries can use RSM optimization in the manufacturing domain.

Multifunctional 1D/2D silver nanowires/MXene-based fabric strain sensors for emergency rescue

Abstract Monitoring the vital signs of the injured in accidents is crucial in emergency rescue process. Fabric-based sensing devices show a vast range of potential applications in wearable healthcare monitoring, human motion and thermal management due to their wearable flexibility and high sensitivity. Nevertheless, flexible electronic devices for both precise monitoring of health under low strain and motion under large strain are still a challenge in extremely harsh environment. Therefore, development of sensors with both high sensitivity and wide strain range remains a formidable challenge. Herein, a wearable flexible strain sensor with a one-dimensional/two-dimensional (1D/2D) composite conductive network was developed for healthcare and motion monitoring and thermal management by coating 1D silver nanowires (AgNWs) and 2D Ti3C2Tx MXene composite films on nylon/spandex blended knitted fabric (MANS). The MANS strain sensor can simultaneously achieve high sensitivity (gauge factor for up to 267), a wide range of detection (1–115%), excellent repeatability and cycling stability (1000 cycles). The sensor can be utilized for human health monitoring including heartbeat, pulse detection, breathing and various human motion. Moreover, the MANS sensor also has the electrical heating properties and voltage control temperature between 20-110 °C can achieved at low voltage. In addition, the MANS shows hydrophobicity with water contact angle of 137.1°. The MXene/AgNWs composite conductive layer with high sensitivity under low and large strains, electrical thermal conversion, and hydrophobicity has great potential for precisely monitoring health and motion of the injured in emergency rescue in harsh environment.

Reducing Plastic Waste and Generating Bioelectricity Simultaneously through Fuel Cells Using the Fungus Pleurotus ostreatus

Plastic waste, a persistent and escalating issue, and the high costs of installing electric power, particularly in remote areas, have become pressing concerns for governments. This research proposes a novel method for generating electric power from sugarcane bagasse waste and reducing plastic waste. The key to this method is the use of the fungus Pleurotus ostreatus in microbial fuel cells. Microbial fuel cells (MFCs) demonstrated their effectiveness by generating peaks of electric current (4.325 ± 0.261 mA) and voltage (0.427 ± 0.031 V) on day twenty-six, with a pH of 5.539 ± 0.278. The peak electrical conductivity of the substrate was 130.574 ± 4.981 mS/cm. The MFCs were able to reduce the chemical oxygen demand by 83%, showing a maximum power density of 86.316 ± 4.724 mW/cm2 and an internal resistance of 37.384 ± 62.522 Ω. The infrared spectra of the plastic samples showed a decrease in the peaks 2850–2920, 1470, and 720 cm−1, which are more characteristic of plastic, demonstrating the action of the Pleurotus ostreatus fungus on the plastic samples. Also, the micrographs taken by SEM showed the reduction in the thickness of the plastic film by 54.06 µm and the formation of microstructures on the surface, such as pores and raised layers of the sample used.