Hasil untuk "Electric apparatus and materials. Electric circuits. Electric networks"

Md. Ibrahim Kholil, Alexey Lipatov, Saman Bagheri et al.

ABSTRACT We present a synthetic procedure for large Ti2CTx MXene monolayers with the majority of flakes having sizes of 10–15 µm and the largest ones reaching 40 µm, which are used for device fabrication and electrical measurements on a single‐flake level. We demonstrate that if exposed to ambient conditions, Ti2CTx monolayers oxidize in an aqueous solution or on a substrate on a time scale of hours, but multilayer flakes are more resistant to environmental degradation. The partially oxidized monolayer Ti2CTx flakes exhibit low electrical conductivity and electron mobility, as well as the semiconducting‐like temperature dependence of resistance with dR/dT < 0. However, the more degradation‐resistant multilayer flakes show electrical conductivity of about 3700 S cm−1 and electron mobility of about 1.6 cm2 V−1 s−1, which are among the highest values reported for MXene materials, as well as the metallic temperature dependence of resistance with dR/dT > 0, which is expected for Ti2CTx with mixed surface terminations (Tx = ─F, ─OH, = O) based on prior theoretical calculations. These results correlate with the electrical measurements of Ti2CTx films, which showed that the thicker films exhibit better environmental stability. The characteristics of multilayer flakes suggest high intrinsic electrical conductivity of Ti2CTx and justify its potential for electronic applications.

Tim Greitemeier, Achim Kampker, Jens Tübke et al.

Battery production for electric vehicles (EVs) necessitates a supply chain capable of supporting the exploitation of a variety of raw materials. Lithium, nickel, manganese, and cobalt are of particular significance for the dominant lithium-ion battery (LIB) technology, primarily relying on lithium iron phosphate (LFP) and lithium nickel manganese cobalt oxide (NMC) cathodes. Geographically, the global supply is heavily reliant on China with competition expected to intensify. In light of this, the questions of how global competition manifests at the company level and whether regions capture their share of the supply chain through domestic companies remain unanswered. These are addressed by analyzing the companies behind each supply chain sector and the respective raw materials. The results demonstrate that China, Europe, and the United States of America (USA) exhibit the most pronounced ownership across the supply chain, acquiring the largest foreign shares in the mining sector. Overall, China leads in a total of eleven out of the 12 investigated sectors, with its peak for LFP production at above 98 %. This preeminence, coupled with the substantial output of South Korea, Europe, and Japan in NMC production, the latter represents a viable target for mitigating supply chain vulnerabilities and attaining greater growth and sovereignty.

Xian‐Hu Zha, Yu‐Xi Wan, Shuang Li et al.

Abstract Beta gallium oxide (β‐Ga2O3) is an ultra‐wide‐bandgap semiconductor with advantages for high‐power electronics. However, the power resistance of β‐Ga2O3‐based devices is still much lower than its material limit due to its flat band dispersion at its valence band maximum (VBM) and the difficulty for p‐type doping. Here, β‐Ga2O3‐based new type ternary ultra‐wide bandgap semiconductors: β‐(RhxGa1‐x)2O3’s alloys are reported with x up to 0.5. The energy and band‐dispersion curvature of β‐Ga2O3’s VBM are significantly enhanced via Rh‐alloying. Compared to that in β‐Ga2O3, the β‐(RhxGa1‐x)2O3’s VBMs increase more than 1.35 eV. The hole mass of β‐(Rh0.25Ga0.75)2O3 is only 52.3% of that in β‐Ga2O3. The decreased hole mass is correlated with the equal Rh─O bond along the b‐axis. Thanks to the simultaneous rise of conduction band minimums, the bandgaps of β‐(RhxGa1‐x)2O3 are still much larger than that in commercial silicon carbide. Moreover, the alloys show direct bandgaps in a wide range of x, and a direct and ultra‐wide bandgap of 4.10 eV is determined in β‐(Rh0.3125Ga0.6875)2O3. Combined with the enhanced valence energy, reduced hole mass, and ultra‐wide bandgap, the β‐(RhxGa1‐x)2O3 can be candidate semiconductors for a new generation of power electronics, ultraviolet optoelectronics, and complementary metal‐oxide‐semiconductor (CMOS) technologies.

Tenis Ranjan Munaweera Thanthirige, Michael Flanagan, Ciaran Kennedy et al.

Tidal energy is one of the most predictable and reliable renewable energy sources, capable of generating significant amounts of electricity in the coming decades. Scientists, researchers, and technology developers are working tirelessly to propel the industry forward, employing next-generation innovative design strategies to achieve future milestones in affordable and sustainable power generation. In this context, the validation of novel tidal turbine systems offers significant advantages to developers, enabling them to deploy the devices at various tidal potential sites worldwide with confidence that their designs will be able to withstand loading conditions during operation. A method used to help achieve this is to conduct a structural testing program of their tidal turbine blades, in accordance with DNV-ST-0164 and IEC DTS 62600-3 standards. Within this scope, developers are demanding accelerated, efficient, and reliable testing programs to de-risk innovative designs while traditional instrumentation methods have considerable disadvantages. Therefore, this study addresses these challenges by investigating the use of modern advanced measurement tools and offering recommendations to enhance the structural testing process of tidal turbine blades, aiming to improve testing effectiveness and deliver high-quality results within a shorter time frame. Within this study, laser scanning vibrometer, digital image correlation systems, infrared thermal imaging camera, fibre Bragg grating sensors, and laser displacement measuring sensors were employed, in parallel with the traditionally used sensors, to assess the structural testing program of a helical shape tidal turbine foil and studied the results. This study yields promising outcomes, highlighting the potential use of advanced measurement techniques to enhance the structural testing paradigm for tidal turbine blades for future accelerated testing programs. More importantly, it supports the developers in de-risking their technologies, while establishing a new knowledge base for the effective use of modern measurement tools, ultimately contributing to the reduction of the levelised cost of tidal stream energy devices.

Zhanibek Bizak, Harold F. Mazo‐Mantilla, Linqu Luo et al.

Abstract The intrinsic high non‐linearity of Schottky diodes with the latest improvements in performance, material, and design novelties have made them invaluable in the emerging devices ecosystem. However, the reported studies on diodes based on 2D and metal‐oxide semiconductors for digital circuits are limited to basic logic gates. The Schottky diodes‐based integrated circuit feasibility and scalability discussions are lacking. In this work, the large throughput and cost‐effective adhesion lithography in tandem with the solution‐based method is used to fabricate integrated functional circuits for Arithmetic Logic Unit (ALU). The self‐aligned nanogap separation between interdigitated coplanar aluminum (Al) and gold (Au) electrodes is uniform throughout the fabricated diode width, resulting in a high rectification ratio of 5 × 106. The fundamental logic AND, OR, and XOR gates based on nanogap Schottky diodes are fabricated, from which arbitrary logic and arithmetic functional circuits can be constructed. To demonstrate the large‐area integration, a 3‐bit Binary Shifter circuit is implemented. The measurement‐based Keysight ADS diode model is used to design a complete 4‐bit ALU circuit. The excellent circuit‐level performance, large‐area scalability, design flexibility, and cost‐efficiency of logic circuits based on nanogap Schottky diodes make them promising candidates for future Internet of Things applications.

Ashrafun Naher Pinky, Thomas Ebel, Samaneh Sharbati

This paper demonstrates a fabless design approach for the lateral optimization of a GaN current aperture vertical electron transistor (CAVET). To this end, the length of the current blocking layer (CBL) has been scaled to exhibit the influence of current aperture length on the static characteristics of GaN CAVET e.g. threshold voltage (Vth), on-state resistance (RON), and breakdown voltage (VBR) and C-V characteristics. Results conclude that the on-state resistance decreases with an increase in aperture length for a given length of the device. Devices with large aperture lengths are additionally susceptible to breakdown at low voltages. This observation illustrates a critical trade-off between the on-state resistance and breakdown voltage for different aperture lengths. Considering this trade-off, optimizing aperture length maximizes Baliga's Figure of Merit (BFOM) for power application.

Yili Wang, Yunqi Liu, Yunlong Guo

Abstract With the rapid development of human‐computer interaction and Internet of Things technologies, bioinspired electronics have attracted significant attention due to their excellent compatibility, portability and mechanical flexibility. Over the past few decades, advancements in stretchable organic semiconductor materials and devices have established stretchable organic transistors as versatile platforms for bioinspired electronic systems, owing to their exceptional mechanical stretchability, high biocompatibility, and tunable optoelectronic properties. These devices, with their multifunctionality to simultaneously process and store information, effectively circumvent the von Neumann bottleneck, thereby driving the development of next‐generation bionic intelligence, artificial sensory systems, and neuroprosthetics. In this review, we first provide a comprehensive overview of recent advances in design strategies for stretchable organic transistors, encompassing design of intrinsically stretchable materials and structural engineering approaches. Next, we summarize their applications in bioinspired electronics, particularly in neuromorphic devices and skin‐like sensors. Finally, we discuss the prospects and challenges of stretchable organic transistor‐based bioinspired electronics, ranging from the design of intrinsically stretchable organic materials to their practical implementation, thereby laying a solid foundation for next‐generation prosthetic skins, human‐machine interfaces, and neurorobotics.

Fatme Jardali, Jenny L. Chong, Yeonju Yu et al.

Abstract Artificial neurons exhibiting volatile threshold switching and action potential‐like oscillations are crucial for brain‐inspired computing. While Complimentary Metal‐Oxide‐Semiconductor (CMOS)‐based strategies require hundreds of transistors to simulate each neuron, neuronal oscillations arise spontaneously in individual electro‐thermal devices due to nonlinearities like the Mott transition in VO2. Despite improved understanding of the physics, quantitative connections between neuronal performance and material properties remain under‐explored, preventing predictive neuron design and rational materials selection. In this work, a physics‐aware forward design methodology is developed for interrogating a wide palette of materials with properties varying by orders of magnitude, and their performance (high frequency, high dynamical reconfigurability and low power) under external circuit and device geometry constraints is assessed. The space of viable materials is identified to be much larger than previously recognized, with candidates from a range of materials classes, including Ge, GaP and MoS2. CMOS‐compatible performance (such as 100 GHz oscillating frequencies) can be achieved with CMOS‐compatible node sizes (≈10 nm). Finally, combinations of material properties yielding desired neuronal performance under uncertain design constraints are considered. This work solidifies forward design principles for electro‐thermal neuron devices, a necessary pre‐condition for inverse design from desired neuronal performance to required materials properties.

Yuang Chen, Haojing Tan, Jiahua Zhuang et al.

The interaction mechanism between a single microscopic object like a cell, a particle, a molecule, or an atom and its interacting electromagnetic field is fundamental in single-object manipulation such as optical trap and magnetic trap. Function-on-demand, single-object manipulation relies on a high degree of freedom control of electromagnetic field at localized scales, which remains challenging. Here we propose a manipulation concept: programmable single-object manipulation, based on programming the electromagnetic field in a multi-bit electrode system. This concept is materialized on a Programmable Electric Tweezer (PET) with four individually addressed electrodes, marking a transition from function-fixed single-object manipulation to function-programmable single-object manipulation. By programming the localized electric field, our PET can provide various manipulation functions for achieving precise trapping, movement and rotation of multiscale single microscopic objects, including single proteins, nucleic acids, microparticles and bacteria. Implementing these functions, we are able not only to manipulate the object of interest on demand but also quantitatively measure the charge to mass ratio of a single microparticle via the Paul trap and the electrical properties of an individual bacterial cell by the rotation analysis. Finally, with superposed single-particle trapping and rotation, we demonstrate the spontaneous relaxation of DNA supercoiling and observe an unexpected pause phenomenon in the relaxation process, highlighting the versatility and the potential of PET in uncovering stochastic biophysical phenomena at the single-molecule level.

Chengmin Wang, Jun Liu, Hongchao Zhang et al.

Laser Charging means high energy laser beam to irradiate the solar cell to gain electricity power through photovoltaic generation. This kind of wireless energy transform way fits the IoT and other low energy satiation with the benefit of long-distance transmission. In this paper, we present a new way of information transferring while energy is gained which is called Simultaneous Wireless Information and Power Transfer. The main idea is to switch the laser device output power to generate the different PV current values, the dual level of laser power decides two ranges of the value. We imitate the On-Off Keying (OOK) named Low-High Keying(LHK) which turns the information into the energy code with a high or low current value. The issue of information coding is also presented with an example. And the application also provided the realization presented. The new method provides a brand way to Simultaneous Wireless Information and Power transfer without any extra equipment by contrast with others. It's suited for the long-distance, low power and limited information-connected occasions.

William R. Tavares, Rudnei O. Ramos, Ricardo L. S. Farias et al.

We study the symmetry breaking and restoration behavior of a self-interacting charged scalar field theory under the influence of a constant electric field and finite temperature. Our study is performed in the context of the optimized perturbation theory. The dependence of the effective potential with constant electric fields is established by means of the bosonic propagators in the Schwinger proper-time method. Explicit analytical expressions for the electric and thermal contributions are found. Our results show a very weak decreasing behavior of the vacuum expectation value as a function of the electric field, which is strengthened by the temperature effect. A first-order phase transition that occurs at zero/weak electric fields changes to a second-order phase transition under strong electric fields. The critical temperature for the phase transition exhibited a very weak dependence on the electric field. Additionally, we computed the vacuum persistence probability rate for the interacting theory, finding a peak at the critical point. The maximum value of this rate at the critical point is found to be independent of the coupling constant but depended solely on the magnitude of the electric field.

D. Damodaram, Rakesh Kumar Godi, Rajkumar et al.

Several researchers would study the development of controlling and centralized management approaches in response to improvements in wireless communication, microsystems, microcontrollers, deeply integrated computers, deeply integrated devices, and the expanding demand for more productive controlled electric equipment. The objective is to develop a computerized device that employs Wireless Sensor Networks (WSN) and Dynamic Power Management (DPM) to supervise and troubleshoot the electrical system. The Intelligent Sensor Modules (ISM) and isolated data automation systems, that are in charge of Signal Detection, Computing, and Transmission, have been deployed on two network architectures (SDCT). The data collection devices must be accepted by the Remote Servers (RS) design, and the monitoring inverter serves as the wired connection's gateway. A DPM approach is used by the sensor networks to extend the WSN's lifespan. By simply extending the sleep duration, which could be modified according to the application operating on the sensor network, the life of the node can be easily increased.

Hugo De Souza Oliveira, Federica Catania, Albert Heinrich Lanthaler et al.

Abstract Innovation in materials and technologies has promoted the fabrication of thin‐film electronics on substrates previously considered incompatible because of their chemical or mechanical properties. Indeed, conventional fabrication processes, typically based on photolithography, involve solvents and acids that might harm fragile or exotic substrates. In this context, transfer techniques define a route to overcome the issues related to the nature of the substrate by using supportive carriers in the electronics stack that mitigate or avoid any damages during the fabrication process. Here, a substrate‐free approach is presented for the transfer of ultra‐thin electronics (<150nm‐thick) where no additional layer besides the electronics one remains on the final substrate. Devices are transferred on several surfaces showing good adhesion and an average performance variation of 27%. Furthermore, a sensor bent to a radius of 15.25µm, shows variation in performance of 5%. The technique can also be sequentially repeated for the fabrication of stacked electronics, enabling the development of ultra‐thin devices, compliant on unconventional surfaces.

Mustafa B. Dawood, Hawra Mohamed Ali M. Taher

The results of an experimental study into the flexural and shear conduct of continuous two span unbonded posttensioned high strength concrete beams subjected to static and a limited number of repeated loading cycles are presented in this paper. The experimental program comprising testing and experimentation of four continuous unbonded posttensioned high strength beams with a total length (4300) mm. The main objective of this study was to see how the strength and serviceability of continuous prestressed concrete beams were affected by restricted repeated loading cycles. As a result, these beams were split into two similar groups. The first set consisted of two beams to study the flexural behavior. The second set consisted of two beams to study the shear behavior. For each set one tested under static loads and the second tested under repeated loads. They were subjected to two concentrated loads in the middle of each span loads up to destruction. It was determined that the repeated load ranged between 0.4 and 0.6 of the ultimate load generated by the static test. Immediately following the ten cycles, the load was withdrawn, and the beams were subjected to a monotonic static test until failure was achieved. Recorded the cracking and ultimate load capacity, midspan deflections, and crack widths. The experimental results explained that the ultimate flexural and shear strength for beams that are tested under repeated loads is a little reduced (1.7%) and (3.9%) comparing with the strength of the identical beams under monotonic static loading and increasing the ultimate deflection after ten cycles of repeated loading, decreased about (5.3%) and (15.1%) for flexural set and shear set, respectively.

Patrick P. Mercier, Steven M. Bowers

Radios are everywhere. They allow us to watch terrestrial TV broadcasts, connect our cars to satellite-based navigation systems, and connect our computers, phones, and other smart devices to the Internet. As the Internet of Things continues to proliferate, radios will start to connect food packaging, pets, environmental monitors, and all sorts of other things to the Internet as well. A large percentage of these emerging applications will operate on either very small batteries or small energy harvesters, and thus must support all application requirements on very tight power budgets. Since radios often dominate the power consumption of low-power sensing nodes, anything we can do to help reduce the power consumption of wireless communications will help enable these new applications. Of course, this should be accomplished thoughtfully, with careful consideration of coexistence, standards, regulations, security, privacy, and other application-level constraints.

Bang Liu, Li-Hua Zhang, Zong-Kai Liu et al.

Microwave sensing has important applications in areas such as data communication and remote sensing, so it has received much attention from international academia, industry, and governments. Atomic wireless sensing uses the strong response of the large electric dipole moment of a Rydberg atom to an external field to achieve precise measurement of a radio frequency (RF) electric field. This has advantages over traditional wireless sensing. The advantage of a Rydberg atom is its ultra-wide energy level transitions, which make it responsive to RF electric fields over a wide bandwidth. Here, we briefly review the progress of electric field measurement based on Rydberg atoms. The main contents include the properties of Rydberg atoms, measurement using Rydberg atoms, and experimental progress in electric field measurement in different bands. We show the different methods for detecting electric fields such as atomic superheterodyne, machine learning, and critically enhanced measurement. The development of Rydberg atomic measurement focuses on the advantages of Rydberg atomic sensing, especially compared with conventional microwave receivers. This is of major significance to developing Rydberg-based measurement in astronomy, remote sensing, and other fields.

Melisa M. Gianetti, Roberto Guerra, Andrea Vanossi et al.

We theoretically explore the effect of a transverse electric field on the frictional response of a bi-layer of packed zwitterionic molecules. The dipole-moment reorientation promoted by the electric field can lead to either stick-slip or smooth sliding dynamics, with average shear stress values varying over a wide range. A structure-property relation is revealed by investigating the array of molecules and their mutual orientation and interlocking. Moreover, the thermal friction enhancement previously observed in these molecules is shown to be suppressed by the electric field, recovering the expected thermolubricity at large-enough fields. The same holds for other basic tribological quantities, such as the external load, which can influence friction in opposite ways depending on the strength of the applied electric field. Our findings open a route for the reversible control of friction forces via electric polarization of the sliding surface.

Elmer Sorrentino, Andres Vera

Abstract This article shows an improved equation to describe the induction motor currents during a three‐phase short‐circuit near to motor terminals. The proposed equation considers three details which are not in the equation shown in the IEEE Std. 551: (a) the equivalent frequency of these currents is not strictly equal to the grid frequency; (b) the magnitude of the DC component is not strictly equal to the magnitude of the AC component; (c) an angle is included to consider the instant of fault occurrence. The proposed equation was verified by experimental results, which were also verified by simulations. It is shown that the equivalent frequency of analysed currents is not exactly the grid frequency due to the sudden change of the machine speed (caused by the high braking torque originated by high transient currents during the short‐circuit). This effect is larger in smaller motors. The AC and DC components of the analysed currents have their own time constants, which are usually estimated from motor equivalent circuit. The application of the improved equation was useful to demonstrate that such a procedure does not lead to accurate results in case of the DC time constants of small motors. Finally, an example illustrates a case that cannot be well described by the equation from the IEEE Std. 551, whereas the result from the proposed equation is very similar to the measured current.

S. Sivachandiran, K. Jagan Mohan, G. Mohammed Nazer

Recently, person detection and tracking in a video scene of a surveillance system were grabbing higher interest because of its extensive range of applications in gender classification, abnormal event recognition, person identification, human gait characterization, individual counting in a dense crowd, and fall detection for older people, etc. Several methodologies were implied for person detection for surveillance applications. This paper presents a new DL driven automated person detection and tracking (DLD-APDT) model on surveillance videos. The major goal of the proposed DLD-APDT model is to identify people and track them in the videos. To accomplish this, the proposed DLD-APDT model initially performs frame conversion process where the input video is converted into a set of frames. In addition, the proposed DLD-APDT model employs EfficientDet model as object detector, i.e., persons and track them. EfficientDet is a recently developed object detector that makes use of different optimization and backbone tweaks, like bi-directional feature pyramid network (BiFPN) and a compound scaling approach. Moreover, root means square propagation (RMSProp) optimizer is applied to optimally choose the hyperparameters related to the EfficientNet model which helps in accomplishing enhanced performance. The experimental validation of the DLD-APDT model takes place using two training datasets namely PascalVOC and PenFudan datasets. The simulation results reported the enhanced detection and tracking performance of the DLD-APDT technique over recent approaches.

Enrico Genco, Marco Fattori, Pieter J. A. Harpe et al.

This article presents a multiplexed current sensitive readout for label-free zeptomolar-sensitive detectors realized with large-area electrolyte-gated organic thin-film transistors (EGOFETs). These highly capacitive biosensors are multiplexed using an organic thin-film transistor (OTFT) line driver and OTFT switches and interfaced to a 65-nm Si CMOS, low-power, pA-sensitive front-end. The Si chip performs analog-to-digital conversion and data transmission to a microcontroller too. A current domain interface is used to transmit the signals coming from multiple biosensors to the 1.2-V supply CMOS Si-IC via the 30-V supply OTFT electronics. Exploiting an analog module implemented in the Si-IC, the EGOFETs are precisely biased, even in the presence of a large OTFT multiplexer resistance. The CMOS current sensitive front-end achieves a dynamic range (DR) of 137 dB and a power consumption of 42-<inline-formula> <tex-math notation="LaTeX">$\mu \text{W}$ </tex-math></inline-formula> per channel reaching a state-of-the-art DR-power-bandwidth FOM of 208 dB. The front-end has been designed with a first-stage programmable-gain, active-feedback transimpedance amplifier topology that, contrary to common current-sensitive front-end solutions, is not affected by the sensor capacitance. The system has been validated with different concentrations of human IgG and IgM proteins using both a single sensor and a 4 <inline-formula> <tex-math notation="LaTeX">$\times $ </tex-math></inline-formula> 4 array of EGOFETs. Thanks to the multiplexing strategy and the low costs of its modules, the system here presented has the potential to enable widespread use of precision diagnostic with extreme sensitivity even in point-of-care and low-resource settings.