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

S. Ramo, J. Whinnery, T. Duzer

Peiran Xu, Tiantian Huang, Qingzi Li et al.

ABSTRACT Environment‐adaptabilities are always critical for optical and electrical components while Ga2O3 thin films have been attractive in UV photodetectors, flexible optoelectronics and multifunctional integrations. Here, we present the atomic‐layer deposited amorphous Ga2O3 thin films and the solar‐blind UV photodetectors with temperature‐adaptabilities across a wide temperature range of 100–450 K. The devices exhibit an excellent responsivity (∼3.99 mA/W) and detectivity (∼1.19 × 1011 Jones) at 120 K, and remain operational during temperature changes between 100 and 450 K. The distinct non‐monotonic variations that were observed in the UV photoresponses may originate from the thermal‐driven evolution of oxygen‐vacancy‐related trap states. We believe that these investigations will provide an alternative approach to understanding amorphous Ga2O3 thin films and temperature‐tolerant devices, and exploring reliable integration used for sensing and observation under extreme environment changes.

Yu Teng, Jian Yao, Qinan Wang et al.

As circuit integration continues to advance, power consumption has become a critical bottleneck limiting further development. Multi‐valued logic (MVL) has garnered extensive attention due to its potential to reduce interconnect complexity and switching losses. Single‐walled carbon nanotubes (SWCNTs), with their superior electrical properties, ultra‐small dimensions, and controllable aligned array growth, offer unique advantages for the large‐scale fabrication of high‐density MVL circuits. However, progress in this field using SWCNTs remains relatively lagging compared to two‐dimensional materials, primarily due to device stability issues arising from challenges in precise doping control. Here, we demonstrate a system consisting of acetylacetonate metal molecules encapsulated within SWCNTs (M(acac) x @s‐SWCNT), in which carrier concentration can be dynamically modulated under an applied electric field. Transistors based on this platform validate that this electric‐field‐controlled modulation yields three well‐defined logic states: 0, 1, and 2. These transistors demonstrate good uniformity and stable operation, showing a static power consumption of 8.2 pW and dynamic power consumption of 0.31 nJ (state 0 to 1) and 0.35 µJ (state 1 to 2). The ternary inverter based on this heterostructure exhibits rail‐to‐rail output capability, enabling the accurate execution of MVL operations. Ternary weight networks (TWNs) built with these transistors reduce computational complexity and storage, enabling efficient neuromorphic computing.

Yi-Feng Luo, Guan-Jhu Chen, Chun-Liang Liu et al.

: As lithium-ion batteries become increasingly prevalent in electric scooters, vehicles, mobile devices, and energy storage systems, accurate estimation of remaining battery capacity is crucial for optimizing system performance and reliability. Unlike traditional methods that rely on static alternating internal resistance (SAIR) measurements in an open-circuit state, this study presents a real-time state of charge (SOC) estimation method combining dynamic alternating internal resistance (DAIR) with artificial neural networks (ANN). The system simultaneously measures electrochemical impedance ∣ Z ∣ at various frequencies, discharge C-rate, and battery surface temperature during the discharge process, using these parameters for ANN training. The ANN, leveraging its superior nonlinear system modeling capabilities, effectively captures the complex nonlinear relationships between AC impedance and SOC through iterative training. Compared to other machine learning approaches, the proposed ANN features a simpler architecture and lower computational overhead, making it more suitable for integration into battery management system (BMS) microcontrollers. In tests conducted with Samsung batteries using lithium cobalt oxide cathode material, the method achieved an overall average error of merely 0.42% in self-validation, with mean absolute errors (MAE) for individual SOCs not exceeding 1%. Secondary validation demonstrated an overall average error of 1.24%, with MAE for individual SOCs below 2.5%. This integrated DAIR-ANN approach not only provides enhanced estimation accuracy but also simplifies computational requirements, offering a more effective solution for battery management in practical applications.

Fabio Silva, Pedro Pinho, Nuno Borges Carvalho

The rise in popularity of the Internet of Things (IoT) has increased the need to power devices wirelessly, a process called Wireless Power Transfer (WPT), to avoid the usage of batteries, which present limited lifespans. In particular, Microwave Power Transfer (MPT), both Near-field (NF) and Far-field (FF), use Electromagnetic (EM) waves to transfer power between two points. However, these systems still present some downsides, mainly efficiency-wise. This paper explores the usage of Multibeam Antennas (MBAs), specifically Beamforming Network (BFN)-based ones, to improve the capabilities of traditional MPT and Radio Frequency Energy Harvesting (RFEH) systems. The paper starts by introducing the usage of MPT in IoT applications and how MBAs could help solve some of them or at least mitigate them. Afterward, a general explanation of the typical MBAs architectures, including Passive Multibeam Antennas (PMBAs), Multibeam Phased-Array Antennas (MBPAAs), and Digital Multibeam Antennas (DMBAs) is presented, along with their advantages, drawbacks, and some emerging trends. After introducing the typical architectures of MBAs, a comprehensive literature survey is done around rectennas and MPT Transmitters (TXs). This approach allows us to understand better why some architectures are more present than others in both applications, highlighting the exclusive usage of PMBAs in rectennas due to them not using energy. To finalize the paper, using the literature survey done, some challenges associated with integrating MBAs in MPT and RFEH are presented, along with some works presenting ways to mitigate them.

Madison Mooney, Lauren Pandolfi, Yunfei Wang et al.

Abstract Semiconducting polymers offer synthetic tunability, good mechanical properties, and biocompatibility, enabling the development of soft technologies previously inaccessible. Side‐chain engineering is a versatile approach for optimizing these semiconducting materials, but minor modifications can significantly impact material properties and device performance. Carbohydrate side chains have been previously introduced to improve the solubility of semiconducting polymers in greener solvents. Despite this achievement, these materials exhibit suboptimal performance and stability in field‐effect transistors. In this work, structure–property relationships are explored to enhance the device performance of carbohydrate‐bearing semiconducting polymers. Toward this objective, a series of isoindigo‐based polymers with carbohydrate side chains of varied carbon‐spacer lengths is developed. Material and device characterizations reveal the effects of side chain composition on solid‐state packing and device performance. With this new design, charge mobility is improved by up to three orders of magnitude compared to the previous studies. Processing–property relationships are also established by modulating annealing conditions and evaluating device stability upon air exposure. Notably, incidental oxygen‐doping effects lead to increased charge mobility after 10 days of exposure to ambient air, correlated with decreased contact resistance. Bias stress stability is also evaluated. This work highlights the importance of understanding structure–property relationships toward the optimization of device performance.

Wenjie Wang, Lina Han, Junwei Qiao et al.

High-entropy oxide ceramics (HEOCs) hold promising potential for diverse applications, as their properties can be precisely tailored through the strategic selection of elements and adjustment of doping ratios. While structural and coating materials represent the most widespread and fundamental applications of high-entropy materials, comprehensive reviews focusing on these domains remain scarce. In this Perspective, we highlight diverse structural and coating oxide ceramics that have emerged since the discovery of high-entropy ceramics. Despite the relatively short history of high-entropy materials, we analyze classic-case studies that correlate phase structures with performance, systematically compiling and contrasting findings to guide future research. An overview of intrinsic properties in these cases, such as crystal structures, synthesis methodologies, mechanical properties, and thermal-insulation capabilities, is given and presented visually through images and tables. This synthesis not only clarifies the current landscape but also establishes a framework for advancing high-entropy ceramic studies, providing a foundational reference for researchers exploring novel material designs and applications.

Liguang Gong, Hongping Jiang, Bin Lao et al.

Abstract Strain engineering offers a powerful route to tailor topological electronic structures in correlated oxides, yet conventional epitaxial strain approaches introduce extrinsic factors such as substrate‐induced phase transitions and crystalline quality variations, which make the unambiguous identification of the intrinsic strain effects challenging. Here, a flexural strain platform is developed based on van der Waals epitaxy and flexible micro‐fabrication, enabling precise isolation and quantification of intrinsic strain effects on topological electronic structures in correlated oxides without extrinsic interference. Through strain‐dependent transport measurements of the Weyl semimetal SrRuO3, a significant enhancement of anomalous Hall conductivity (AHC) by 21% is observed under a tiny strain level of 0.2%, while longitudinal resistivity remains almost constant—a hallmark of intrinsic topological response. First‐principles calculations reveal a distinct mechanism where strain‐driven non‐monotonic evolution of Weyl nodes across the Fermi level, exclusively governed by lattice constant modulation, drives the striking AHC behavior. This work not only highlights the pivotal role of pure lattice strain in topological regulation but also establishes a universal platform for designing flexible topological oxide devices with tailored functionalities.

Cigdem Cakirlar, Bruno Neckel Wesling, Konstantinos Moustakas et al.

Abstract Research on transistors with various architectures is crucial for developing high‐performance, compact devices, as they improve the functionality of integrated circuits within the same or smaller footprint. Simulation studies have shown that transistors fabricated using a U‐shape channel have a higher functionality as their natural geometry enables the realization of gate‐all‐around structures and long channel lengths within a small footprint. The experimental realization of the transistor is essential for exploring circuit applications. This paper presents the process integration route and the first experimental results of a U‐shape ambipolar Schottky barrier field effect transistor. Also, a detailed explanation of the challenges in fabricating a 3D transistor and the improvement steps are given. The fabricated device demonstrates highly symmetrical on‐currents for both p‐ and n‐branches. Self‐aligned contact formation and atomic force microscopy imaging are used to simplify fabrication and facilitate 3D structural monitoring. In addition, the formation of self‐aligned contacts in the proposed device architecture is significantly simplified compared to traditional 3D architectures. TCAD simulations are also performed to support the experimental findings and demonstrate the device's future potential and scalability. In conclusion, it effectively addresses the challenges of the fabrication of 3D transistors and drives innovations in device design with its silicon‐on‐insulator body.

B. S. B. Mobarak, Hany Aziz

Abstract Despite their potential advantages over widely used ZnO, the use of organic materials for the electron transport layers (ETLs) in quantum dot light‐emitting devices (QLEDs) has been limited by subpar external quantum efficiency (EQE). This work investigates the root causes of this issue and approaches to address them. Contrary to expectations, electron leakage toward the hole transport layer (HTL) is identified as a plays a primary role in limiting the efficiency of these devices. By using a multilayer ETL configuration that includes electron blocking interfaces, electron leakage is reduced, and higher EQE is achieved. Using this approach, a max EQE of ≈10% in green‐ and red‐emitting QLEDs, the highest reported for a green QLED not utilizing a ZnO ETL and among the highest in the case of red QLEDs, has been demonstrated. Tests on electron‐only devices as well as transient electroluminescence measurements point to a mechanism where the formation of electron space charges within the organic ETLs may be assisting hole injection in the quantum dot layer, thus helping to reduce leakage. The findings highlight the importance of layer interface engineering and leakage control for achieving higher EQE in QLEDs, and present strategies for the effective utilization of organic ETLs in them.

Do Yun Park, Hye‐Min Lee, Su‐Hwan Kim et al.

Abstract Wearable and implantable devices provide users with continuous monitoring and treatment, and bioresorbable features can facilitate the use of temporary biomedical devicesand reduce electronic wastes (e‐wastes). Bioresorbable metals and polymers offer multiple benefits, such as high conductivity and mechanical support, for skin‐interfaced and implantable biomedical devices in versatile biomedical applications. These materials dissolve naturally after their targeted lifetime, avoiding complications arising from retrieval surgeries and preventing e‐waste accumulation. This review summarizes recent advances in both bioresorbable materials and devices, highlighting various polymers, semiconductors, and metal options along with their dissolution processes. The following contents introduce the current developments in bioresorbable skin‐interfaced and implantable systems including electrostimulation (ES), energy harvesting, sensor, and transistor systems. A concluding section discusses current challenges and future research opportunities in this field.

Jin Liu, Wei-Wu Jin, Zhao-Fan Cai et al.

Topological phase transitions can be remarkably induced purely by manipulating gain and loss mechanisms, offering a novel approach to engineering topological properties. Recent theoretical studies have revealed gain-loss-induced topological disclination states, along with the associated fractional charge trapped at the disclination sites. Here, we present the experimental demonstration of topological disclination states in a purely lossy electric circuit. By designing alternating lossy electric circuit networks that correspond to the disclination lattice, we observe a voltage response localized at the disclination sites and demonstrate the robustness of these states against disorder. Furthermore, we measure the charge distribution, confirming the presence of fractional charge at the disclination sites, which gives rise to the topological disclination states. Our experiment provides direct evidence of gain-loss-induced topological disclination states in electric circuits, opening new possibilities for applications in classical systems.

S. Shinderuk, Y. Batygin

The purpose of this work is to propose and substantiate the workability of a magnetic-pulse complex for attracting thin-walled metals, consisting of two successive circuits with a common capacitive energy storage device, the first of which is a resonant charger powered by an industrial voltage and frequency network, and the second unit is a discharge circuit with an inductor-tool for performing the assigned production task. When deriving the main analytical relationships for calculating the characteristics of the proposed resonant magnetic-pulse complex designed to attract sheet metals and operating as a resonant amplifier of the energy of an electric signal from an industrial voltage and frequency network, the mathematical apparatus of the theoretical foundations of electrical engineering and methods of integrating differential equations were used. The high efficiency of resonant formation of charge characteristics of a capacitive electric energy storage device from an industrial network of ~ 220 V at a frequency of ~ 50 Hz for ~ 0.1 s to a voltage of ~ 4595.85 V (gain is ~ 14.78 times) with a stored energy of ~ 2640 J (energy of the source ~ 8.47%, resonant energy ~ 91.53%) is shown. For a discharge circuit at a frequency of ~ 1500 Hz, it was obtained that the maximum energy in the inductor-tool is ~ 8.25 times higher than the energy consumed from an external power source. The discharge current in the inductor-tool is ~ 45270.4 A. With this current value there should be a sufficiently effective force impact on the workpiece.

Valeriy Pupin, Dmitry Safonov, Oleg Fedorov

The presence of own sources of electricity in the conditions of joint operation of autonomous and centralized power sources of power supply systems imposes the need to use a special mathematical apparatus for the study of short-circuit modes. The mathematical model of the power supply system with autonomous and centralized sources proposed by us takes into account the closed electric network of sewage treatment plants. Computational studies of various types of short circuits in a combined circuit with autonomous and centralized power sources have been carried out, which confirm an increase in the accuracy of calculations of currents and residual voltages of the network by taking into account the EMF angles of generators, synchronous and asynchronous motors relative to the EMF of the balancing unit.Computational studies have confirmed that the short-circuit currents in the VTE Wassertechnik GmbH division (APVSH-682510.003-PZ project from 2008), with the assumptions adopted there, are overestimated by 15-24%. This led to the choice of switches with a high cut-off current, and also required changes in the relay protection and automation settings. Short-Circuit currents in the supply power system on 110 buses, as well as the 10 and 6 kV distribution network of the electrotechnical complex of sewage treatment plants are compared. The nodes are identified, with a three-phase short circuit, in which dynamic stability is disrupted.

Wudi Ji, Guohua Liu, Yuxiang Gong

This article proposes a novel sensor system for detecting the permittivity of solid materials. The proposed sensor system consists of three parts: planar microwave sensor, RF oscillator, and differential measurement circuit. The planar microwave sensor is based on an electric LC (ELC) structure, with two microstrip lines (MTLs) acting as ports, and achieves a transmission zero frequency at 1.93 GHz. The low noise amplifier (LNA) based on the ATF54143 transistor, combined with a positive feedback loop, satisfies the Barkhausen criteria and forms an oscillator, with a no-load oscillation frequency of 2.36 GHz. Differential measurement circuits employ a mixer and a frequency detector to measure frequency and obtain the permittivity of the material under test (MUT), effectively reducing the influence of environmental factors on the oscillator frequency. This scheme replaces the need of vector network analyzers (VNAs), thereby reducing the cost of measuring instruments.

Zhichao Xie, Chenyu Zhuge, Chunyang Li et al.

Complementary neural network circuits combining multifunctional high-performance p-type with n-type organic artificial synapses satisfy sophisticated applications such as image cognition and prosthesis control. However, implementing the dual-modal memory features that are both volatile and nonvolatile in a synaptic transistor is challenging. Herein, for the first time, we propose a single vertical n-type organic synaptic transistor (VNOST) with a novel polymeric organic mixed ionic-electronic conductor as the core channel material to achieve dual-modal synaptic learning/memory behaviors at different operating current densities via the formation of an electric double layer and the reversible ion doping. As a volatile synaptic device, the resulting VNOST demonstrated an unprecedented operating current density of MA cm-2. Meanwhile, it is capable of 150 analog states, symmetric conductance modulation, and good state retention (100 s) for a nonvolatile synapse. Importantly, the artificial neural networks (ANNs) for recognition accuracy of the handwritten digital data sets recognition rate up to 94% based on its nonvolatile feature. This study provides a promising platform for building organic neuromorphic network circuits in complex application scenarios where high-performing n-type organic synapse transistors with dual-mode memory characters are necessitated.

Dr.V.Senthil Sarathi, A. Nayagam, Shanik Dr.S et al.

Mosquitoes are an important vector of disease transmission for human beings, including the West Nile virus, dengue, malaria, and Zika. There are many ways to control these but certain techniques of control, such as pesticides, may have negative effects on the ecosystem. Mosquitoes are ubiquitous carriers of disease that disperse throughout the world. Bed nets, insect repellents, mosquito bats, and kitchen insect killers are examples of prevention techniques. The proposed invention is a sophisticated mosquito-killing electric mesh designed for window/door installation, which can be attached as a window/door for commercial and industrial purposes. It modifies the concept of a mosquito bat insect killer. To develop a project under the domain Embedded Systems and Power Electronics with an innovative creation of a Flexible and affordable insect(mosquito) electric guard and to ensure safety with precautious measures. An ingenious mosquito killer or fly insect mesh employs electric pulses to zap intruders on contact. For added peace of mind, ultrasonic and passive infrared sensors automatically detect and help to deactivate the electric charge if someone approaches the mesh, preventing accidental contact, and the LCD displays a pre-warning message, the status of working, and alarms the buzzer. This innovative project merges effectiveness, ease, and security against pesky pests. The mesh incorporates an electrical system powered by the Electric Board, with a final voltage range of 20 V to 24 V. To safeguard the network circuit, a relay is implemented. Invention automatically powers on and off according to predetermined time settings. The perimeter of the mesh is fortified with plastic or rubber material, and its openable design allows for convenient opening and closing of the window. Additionally, a UV blue light is affixed to the window to attract mosquitoes into the room or hall, enhancing the efficiency of the mosquito or insect-killing system.

Henry Park, Mohammed Abdullatif, Ehung Chen et al.

As modern ASICs integrate several hundred interconnect ports in a large package, ASIC Serdes design faces challenging performance, power, and area targets. Thanks to architectural advancements and technology scaling, a DSP-based transceiver has demonstrated better than 40-dB loss compensation with competitive power and area that enabled very large-scale Serdes integration in a single package. This article reviews two recent publications for long-reach ASIC Serdes designed in 5- and 7-nm FinFET. With detailed discussions on design challenges from major building blocks, TX/RX/PLL, a novel TX data path bandwidth extension technique by a feedback equalizer is proposed with silicon data.

Zain Shafiq, Dimitris E. Anagnostou, Symon K. Podilchak

A circuit-based calibration system is presented for active phased arrays. In particular, to achieve the desired (and corrected) consecutive phase differences and relative magnitudes between RF channels, a computer controlled circuit system was developed for dynamic adjustment. The proof-of-concept demonstrator uses a phase sensor, phase shifters (PSs), and variable gain amplifiers, along with other active hardware, to realize a self-calibrating circuit system which achieves the required magnitude and phase for each array element. In addition, measured magnitude and phase imbalances are less than 0.10 dB and 3<inline-formula><tex-math notation="LaTeX">$^\circ$</tex-math></inline-formula>, respectively. The computer-controlled feed network is then used to demonstrate that the system can automatically calibrate an active antenna array for various beam steering examples. Also, the S-band feed system can self-calibrate due to any monitored magnitude and phase drifts due to temperature changes and practical component ageing, or, other general channel offsets. This can be considered advantageous and simpler when compared to more established approaches which characterize the coupling between elements or the response of the entire array in the near- or far-field for example.