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

Hocine LOUBAR, Razika ZAMOUM BOUSHAKI, Abdellah KOUZOU

A quadcopter is a highly coupled and nonlinear multivariable system which attracted the attention of many researchers. During the last decade, several techniques and strategies have been proposed for modeling and controlling Quadcopters. In this work, dynamic modelling of the quadcopter is formulated using the Newton-Euler method, and a new control approach for quadcopter trajectory tracking is proposed. In this approach, the state space description of nonlinear quadcopter system is transformed into a linear quasi block controller decoupled form, then eigenstructure assignment using state feedback is applied. The proposed approach is used to control a quadcopter, in order to assess its performance in terms of trajectory tracking capabilities, time response performance, robustness and robust stability.

Jaewon Shin, Mototsugu Hamada, Atsutake Kosuge

This paper presents a via-programmable DNN processor architecture, the Via-Programmable Neuron Array (VPNA), designed for low-NRE and low-power AIoT applications. To enable shared base-chip layouts across diverse workloads, a connectivity-aware design ensures tile-to-tile routing under a column-wise placement rule. A <inline-formula> <tex-math notation="LaTeX">$6{\times }6$ </tex-math></inline-formula> programmable-wire structure supports task-specific data paths, and via-based ternary-weight mapping allows multiple tasks to reuse the same base chip with a single via mask. A unified bit-serial neuron circuit supports convolution and pooling operations under both neuron-serial and neuron-parallel modes, completing the functional implementation required for one-dimensional time-series DNNs. Post-layout evaluations in a 40&#x2006;nm CMOS process demonstrate sub-milliwatt power consumption and sufficient inference accuracy across representative AIoT tasks, including keyword spotting, ECG arrhythmia detection, and EEG seizure detection. Compared with prior FPGA- and ASIC-based accelerators, the proposed architecture achieves a better trade-off among low power, low NRE cost, and task-level flexibility, highlighting its potential as a scalable foundation for future ultra-low-NRE and field-programmable AIoT processors.

Cuo Wu, Hao Shen, Richard Schroedter et al.

ABSTRACT Reversible weight tuning is critical for edge AI chips, enabling online learning and local inference. Conventionally, the transition from analog interfacial switching to abrupt filamentary switching in memristors is commonly considered irreversible, as high electric fields induce conductive filaments, locking devices in the filamentary state. Here, we report that TiN/HfO2/Pt memristors exhibit stable interfacial switching and achieve voltage‐driven, repeatable interfacial‐to‐filamentary‐to‐interfacial (I‐F‐I) transitions. Systematic electrical characterization demonstrates more than 10 stable I‐F‐I transition sequences, controllable I‐F‐I transition yield exceeding 40%, a preserved resistance window, and an ON/OFF ratio of about 30. High bias activates a fast digital filamentary mode, while low bias restores a linearly tunable analog interfacial mode. Two defect migration models—soft filament and Schottky emission—elucidate this phenomenon. This analog‐digital switching could in the future, enable single‐chip training and inference and support reconfigurable logic‐in‐memory architectures, advancing low‐power artificial neural networks as well as neuromorphic computing for edge AI applications.

Yuhan Pu, Yung C. Liang

Abstract Conventional GaN‐based UV photodetectors (PDs) suffer from prolonged turn‐off dynamics and high residual off‐state currents, severely limiting their use in high‐speed optoelectronic applications. In this work, a self‐powered, on‐chip AlGaN/GaN photovoltaic‐photodetector integrated configuration (PPIC) that combines photovoltaic energy harvesting and UV photodetection is proposed to address these challenges. Taking advantage of the high conductivity and carrier mobility of the 2D electron gas (2DEG) at AlGaN/GaN heterojunction, the PPIC facilitates an internal gain under the field associated with the photovoltaic (PV) bias and achieves enhanced static photo‐responsivity. Crucially, the PV dynamically biases the PD in synchronization with the UV illumination, ceasing the residual photocarrier collection in dark conditions by eliminating the collection field, thereby effectively suppressing residual current and enhancing frequency response. Apart from competitive static self‐powered performance under 365 nm UV, the PPIC with 0.16 mm2 PV area exhibits outstanding transient performance, including the 3‐dB bandwidth of 6230 Hz and ultrafast rise and fall times of 61.18 and 97.79 µs respectively – over 100‐fold improvement compared to the conventional PD with external bias. Fabricated with CMOS‐compatible processes, the PPIC offers a solution for high‐speed, self‐powered UV photodetection, with transformative potential in applications like optoelectronic communication and UV imaging.

Farnaz Fahimi Hanzaee, Ivan B. Dimov, Luke W. Gatecliff et al.

Abstract Organic electrochemical transistors (OECTs) are attractive devices, particularly for biomedical applications. The inherent quality of OECTs in amplifying signals, combined with the possibility of directly interfacing with biological tissue, make them unique candidates to replace recording electrodes with the added advantage of providing on‐site amplification (and thus allowing them to be counted as active electrodes). While most amplifiers using OECTs are transconductance amplifiers, having voltage‐to‐voltage amplification is more desirable in many applications to make the output compatible with any downstream conditioning circuit. Differential recording of physiological signals has the benefit of rejecting the common‐mode noise sourcing from the environment or the body itself while amplifying the desired signal. Here the considerations for and challenges of designing an OECT‐based differential amplifier are discussed and a three‐transistor amplifier is proposed that can provide a common‐mode rejection ratio of up to ≈20 dB. To demonstrate its advantage, a differential amplifier is used to record ECG signals from a human volunteer, and the collected data is compared with recordings from a Wheatstone bridge OECT amplifier, showing the improved signal‐to‐noise ratio, gain, and power consumption.

Carsten Strobel, Carlos A. Chavarin, Martin Knaut et al.

Abstract Hot electron transistors (HETs) represent an exciting new device for integration into semiconductor technology, holding the promise of high‐frequency electronics beyond the limits of SiGe bipolar hetero transistors. With the exploration of 2D materials such as graphene and new device architectures, hot electron transistors have the potential to revolutionize the landscape of modern electronics. This study highlights a novel hot electron transistor structure with a record output current density of 800 A cm−2 and a high current gain α, fabricated using a scalable fabrication approach. The hot electron transistor structure comprises 2D hexagonal boron nitride and graphene layers wet transferred to a germanium substrate. The combination of these materials results in exceptional performance, particularly in terms of the highly saturated output current density. The scalable fabrication scheme used to produce the hot electron transistor opens up opportunities for large‐scale manufacturing. This breakthrough in hot electron transistor technology holds promise for advanced electronic applications, offering high current capabilities in a practical and manufacturable device.

Changqing Guo, Huayu Yang, Shouzhe Dong et al.

Abstract Advances in flexible electronics are driving the development of ferroelectric thin‐film capacitors toward flexibility and high energy storage performance. In the present work, the synergistic combination of mechanical bending and defect dipole engineering is demonstrated to significantly enhance the energy storage performance of freestanding ferroelectric thin films, achieved through the generation of a narrower and right‐shifted polarization‐electric field hysteresis loop. The recoverable energy storage density of freestanding PbZr0.52Ti0.48O3 thin films increases from 99.7 J cm−3 in the strain (defect) ‐free state to 349.6 J cm−3, marking a significant increase of 251%. The collective impact of the flexoelectric field, bending tensile strain, and defect dipoles contributes to this enhancement. The demonstrated synergistic optimization strategy has potential applicability to flexible ferroelectric thin film systems. Moreover, the energy storage properties of flexible ferroelectric thin films can be further fine‐tuned by adjusting bending angles and defect dipole concentrations, offering a versatile platform for control and performance optimization.

Zuzanna Molenda, Sylvain Chambon, Dario M. Bassani et al.

Abstract The popularity of metal halide perovskites is in part the result of their versatility in numerous applications. To date, perovskites are used in their intrinsic, undoped form, as the doping of these materials is not yet adequately mastered. Herein, the recently reported electronic doping of CH3NH3PbI3 is employed to fabricate perovskite solar cells in which the interfacial electron transport layer (ETL) is replaced by n‐doping of one side of the perovskite film. The doping involves the incorporation of metastable Sm2+ ions that undergo an in situ oxidation to Sm3+, releasing electrons to the conduction band to render the perovskite n‐type. In spite of the lack of an ETL, these solar cells have the same efficiency as the samples with the ETL. The open circuit voltage of the doped solar cells increases proportionally to the doping concentration due to the narrowing of the depletion layer thickness at the interface of the perovskite and the top electrode, reaching the value of ≈1 V for the doped ETL‐free device, the same as for the reference sample. These proof‐of‐concept results represent the first step toward perovskite‐based devices incorporating a p‐n homojunction.

Nicolò Albanelli, Francesco Capodarca, Michele Zanoni et al.

The need for high-energy and safe batteries is more and more urgent, and a possible approach is to use solid polymer electrolyte with high conductivity combined with lithium metal anode. Poly (1,3-dioxolane)-based electrolytes are promising, and the feasibility to polymerize 1,3-dioxolane (DOL) in situ makes this approach very attractive. In this paper, we present the in situ electro-initiated polymerization of DOL in polyacrylonitrile nanofibrous mats, without using initiator or crosslinking agents. The amount of monomer loaded in the porous scaffold, the electrochemical technique used to initiate the polymerization and the salt amount were investigated as important parameters that affect the ion conductivity and the performance of the obtained polymer electrolyte. Particular attention was directed towards minimizing the presence of residual monomer in the resulting polymer, with the aim of progressing towards the development of a real solid-state polymer electrolyte. The results of the thermal, morphological, and electrochemical characterization are reported and discussed.

Junjie Zhang, Guangyuan Chen, Zhenhu Jin et al.

Abstract In recent years, there is a meteoric rise in the prevalence of electronic wearables, and flexible wearables have attracted tremendous attention in human–machine interfaces due to their high biocompatibility, functionality, conformability, and low‐cost. Flexible magnetic smart skin is part of this rapidly progressing field of flexible wearable electronics, which has paved the way for a new path for human perceptual development, as they may form a new perception, also known as magnetic sense, that is, the capacity to detect and interact with magnetic fields. In this review, the concept of the magnetic smart skin is defined: magnetoelastomers and flexible magnetic sensors. In magnetoelastomers, different sources of magnetic field, structures, and applications are summarized by recent and renowned research. In flexible magnetic sensors, different flexible substrates, sensor types, and applications are also summarized. This review further concludes by discussing the outlook and current challenges of magnetic smart skin in human–machine interfaces.

Angel Cuadras, Victoria J. Ovejas, Herminio Martínez García

The present study examines the relationship between thermal and configurational entropy in two resistors in parallel and in series. The objective is to introduce entropy in electric circuits analysis by considering the impact of system geometry on energy conversion in the circuit. Thermal en-tropy is derived from thermodynamics, whereas configurational entropy is derived from network modelling. It is observed that the relationship between thermal entropy and configurational en-tropy varies depending on the configuration of the resistors. In parallel resistors, thermal entropy decreases with configurational entropy, while in series resistors, the opposite is true. The impli-cations of the maximum power transfer theorem and constructal law are discussed. The entropy generation for resistors at different temperatures was evaluated, and it was found that the con-sideration of resistor configurational entropy change was necessary for consistency. Furthermore, for the sake of generalization, a similar behavior was observed in time-dependent circuits, either for resistor-capacitor circuits or circuits involving degradation.

Giorgia Longobardi, Loizos Efthymiou, John Findlay et al.

This work provides an overview of the current state of technology in the field of lateral GaN power devices and presents the characteristics of the main commercially available 650 V GaN power devices and ICs. A comparison is given, both in terms of key parameters as well as of the availability of complex functionality through integration of additional smart features. The features of our new technology, termed ICeGaN™, are presented in this context, focusing on the benefits that may be derived when ICeGaN™ devices are used in common applications. ICeGaN™ is a new concept of a smart HEMT which offers ease-of-use, sensing and protection functions without sacrificing performance.

Keiji Tsubaki, Atsushi Tsurumaki‐Fukuchi, Takayoshi Katase et al.

Abstract In Mott‐type resistive switching phenomena, which are based on the metal–insulator transition in strongly correlated materials, the presence of an abrupt temperature‐driven transition in the material is considered essential for achieving high‐speed and large‐resistance‐ratio switching. However, this means that the freedom of material/device design in applications is significantly reduced for this type of switching by the strict requirement of transition abruptness. Here, high‐speed, abrupt resistive switching with a switching time of 140 ns is demonstrated in epitaxial films of Ca2RuO4/LaAlO3 (001), which is a material with a nonthermal metal–insulator transition driven by current, despite the complete absence of an abrupt thermal transition in the resistivity–temperature characteristics. Highly smooth negative‐differential‐resistance behavior, very high cycling stability, and an endurance over 106 cycles are also demonstrated in the current–voltage and current–time characteristics, which confirm the nonstochastic nature of the abrupt switching. These results suggest that strict control of the resistivity–temperature characteristics is not necessarily required in a material with a nonthermal‐type metal–insulator transition to obtain high‐speed resistive switching because of the independence of the dynamics from those of the thermal transition, and this phenomenon potentially has important advantages in resistive switching applications.

Febin Paul, Krishna Nama Manjunatha, Shashi Paul

Abstract This work focuses on the non‐zero‐crossing and open‐loop current–voltage (I–V) characteristics of electronic memory devices that are studied and focused on primarily for non‐volatile memory storage applications. Gold nanoparticles‐based devices are fabricated to understand possible non‐crossing zero and open‐loop current–voltage behavior, where a non‐zero current and open loop I–V characteristics are observed at zero voltage. While other studies have attributed this behavior as a “battery effect”, this study presents an alternate perspective for non‐redox‐based charge storage memory devices. The electrical measurements clearly demonstrate that the non‐zero current and open‐loop characteristics are due to the charge trapping of the gold nanoparticles. The charge accumulation within the nanoparticle is observed to create a non‐zero potential within the device and thereby encouraging such behavior, even though the applied external voltage is zero. The longstanding mystery in deciphering if electrical measurements or the charge storage device contributes toward non‐zero property is unfurled in this article. A possible charge storage model is proposed and further verified using liquid crystals‐based two terminal devices. The presence of internal potential leads to an offset within the devices, a non‐zero current and open‐loop I–V even when the external applied voltage is zero.

Tatsuhiro Horii, Kei Okada, Toshinori Fujie

Abstract Skin‐contact dielectric elastomer actuators (DEAs) consisting of skin‐conformable, stretchable electrodes are fabricated using a roll‐to‐roll‐based gravure coating method. In this method, single‐walled carbon nanotubes (SWCNTs) are continuously applied on a free‐standing ultra‐thin film (nanosheet) of poly(styrene‐b‐butadiene‐b‐styrene) (SBS) to produce an SWCNT‐SBS nanosheet of 101‐nm thickness. After the first SWCNT coating, the SWCNT‐SBS nanosheet shows a Young's modulus (i.e., 80.9 MPa) comparable to that of the SBS film and a sheet resistance of 4.6 kΩ sq−1. Using the free‐standing SWCNT‐SBS nanosheets as electrodes, a ten‐layered DEA is fabricated without glue or dielectric elastomer precursors on three substrates with different stiffness, namely glass, Ecoflex 00–30, and a urethane elastomer model skin. The low flexural rigidity of the ten‐layered DEA (105 nN m) ensures conformability to the shape of an index finger. Application of an actuation voltage of 2100 V produces a two‐fold larger displacement of the DEA on the Ecoflex 00–30 substrate compared with that on the glass substrate. The ability of the DEA to conform to the surface of skin will enable its application in skin‐contact haptic devices.

Rajarao Banavathu, Sreenivasulu Meruva

In recent years, edge-related smart computing is the way to process and store data via outsourcing environments. Security is the main progressive concept in smart-related Internet of Things (IoT) software denied networks to share and increase the scalability and efficiency in data storage. Because of the rapid growth of different smart services, different security-related problems may appear in resource processing and sharing data in real-time computing systems. To increase the reliability in secure data storage and satisfy the basic requirements related to IoT-related smart computing networks. So propose and implement a Novel Artificial Intelligence based Blockchain Secure Model (NAIBSM) to provide efficient secure data storage in IoT-related smart computing systems. This model flexibly captures each user authentication for the detection of different user-related attacks (i.e. distributed denial-of-service (DDOS)) in the storage of data via applying Artificial Intelligence (AI) calculation method i.e. Leverage Bat algorithm to explore complex features. Build a blockchain at the server side to provide secure communication and reliability of storing data on the terminal of IoT. This approach provides random hash values to each data to ensure blockchain for the integrity of data and uses a weight-based data storage procedure to arrange/store and classify data to each user with secure and unsecured storage in smart computing networks. The experimental results of the proposed model are to explore complex security features and ensure the performance of secure authentication to each user and better security, accuracy, and low communication overhead in IoT-related smart computing data storage and sharing systems.

Bo He, Gang He, Qingqing Hu et al.

Abstract Although In2O3 nanofibers (NFs) are regarded as one of the active channel materials for next‐generation, low‐cost thin‐film transistors (TFTs), these NFs‐based devices still suffer from the degraded carrier mobility and operational instability, limiting the ability of such devices to replace current polycrystalline silicon technologies. Here, it is shown that nanofiber channel transistors with high electron mobility and operational stability can be achieved by selectively doping Zn element into electrospun In2O3 NFs. By precisely manipulating the doping level during NFs fabrication, their crystallinity, surface morphology, and corresponding device performance can be regulated reliably for enhanced transistor performances. It has been detected that InZnO/SiO2 TFTs with an optimized Zn doping concentration of 50% have demonstrated the high field‐effect mobility (µFE) of 6.38 cm2 V−1 s−1, the larger ION/IOFF of 4.12 × 107 and operation in the energy‐efficient enhancement‐mode. Low frequency noise (LFN) measurements have displayed that the scattering and defects inside the NFs are effectively suppressed by the particular microstructure. When integrating ALD‐derived Al2O3 films as the gate dielectric into TFTs devices, their electron mobility and ION/IOFF can be further improved to 37.82 cm2 V−1 s−1 and 2.92 × 108, respectively. To demonstrate the potential toward more complex logic applications, a low voltage resistor‐loaded unipolar inverter is built by using InZnO/Al2O3 TFT, exhibiting a high gain of 20.95 and full swing characteristics. These optimized parameters have demonstrated the significant advance of this electrospinning technique toward practical applications for high performance and large‐scale electronics.

Bhola Khan, Kirubadevi S, Swathi Agarwal et al.

Despite not being uniform, urban economic growth usually shows some inconsistency. Urban sustainable development may be harmed if the financial instability goes above a particular threshold. This article examines the current status of India's macro-economic real-time management of early warning alert systems and information warehouse-related innovations. In order to deal with the significant loss caused by the increased variation of an urban economy, it analyzes and explicates the position of Internet of Things (IoT) technology in the macro-economic alert system. This reviews the development path of financial monitoring and early alerting system whichsorts out and compares numerous popular economic monitoring techniques.Depending on IoT technology, the urban economic reports surveillance &amp; advance warning system has conducted research on information transfer, tracking, forecasts, analysis, and presentation. After simulating the system, the proposed research's findings indicate that the overall accuracy of the model's macroeconomic fluctuation forecast approaches 80%, which may be used in real life.

M. Aamir, Somya Sharma, Anuj Grover

IoT edge devices process the data collected, which can contain sensitive information related to the user. It is crucial to incorporate robust encryption algorithms considering the resource and power budget of these devices. In this paper, we present a power-based SCA-resistant implementation of the ChaCha20 encryption algorithm for low-end devices by utilizing memory arrays. The 10T SRAM-based implementation performs simple operations (like NAND, NOR, XOR) on the bitlines and other operations like addition/subtraction, shifting, rotation on custom-designed in-memory elements tightly coupled to sense amplifiers (SA). The design is verified for multiple test vectors to generate power consumption signatures. Welch&#x2019;s t-test is performed on these signatures to demonstrate that the design is highly resistant to power-based SCA. The proposed implementation of ChaCha20 runs at 250MHz at a 1.2V supply, in 65nm Low Standby Power (LSTP) technology, achieving a speedup of around 7 times in terms of execution time compared to the ARM Cortex A9 processor.

Alistair Forbes

Coordinate metrology can be thought of as a two-stage process, the first stage using a coordinate measuring system to gather coordinate data – point clouds – related to a workpiece surface, the second extracting a set of parameters or characteristics from the data. In this paper, we describe a range of straightforward, approximate models of CMM behaviour that can be used to generate variance matrices associated with point clouds. In particular, we describe models that incorporate spatial correlation to capture the smooth departure of CMM behaviour from ideal geometry. We also discuss how variance matrices associated with point clouds can be propagated through to variance matrices associated with derived features.