Large-scale Integration Research Articles

Myelin Sheath-Inspired Hydrogel Electrode for Artificial Skin and Physiological Monitoring.

Significant advancements in hydrogel-based epidermal electrodes have been made in recent years. However, inherent limitations, such as adaptability, adhesion, and conductivity, have presented challenges, thereby limiting the sensitivity, signal-to-noise ratio (SNR), and stability of the physiological-electrode interface. In this study, we propose the concept of myelin sheath-inspired hydrogel epidermal electronics by incorporating numerous interpenetrating core-sheath-structured conductive nanofibers within a physically cross-linked polyelectrolyte network. Poly(3,4-ethylenedioxythiophene)-coated sulfonated cellulose nanofibers (PEDOT:SCNFs) are synthesized through a simple solvent-catalyzed sulfonation process, followed by oxidative self-polymerization and ionic liquid (IL) shielding steps, achieving a low electrochemical impedance of 42 Ω. The physical associations within the composite hydrogel network include complexation, electrostatic forces, hydrogen bonding, π-π stacking, hydrophobic interaction, and weak entanglements. These properties confer the hydrogel with high stretchability (770%), superconformability, self-adhesion (28 kPa on pigskin), and self-healing capabilities. By simulating the saltatory propagation effect of the nodes of Ranvier in the nervous system, the biomimetic hydrogel establishes high-fidelity epidermal electronic interfaces, offering benefits such as low interfacial contact impedance, significantly increased SNR (30 dB), as well as large-scale sensor array integration. The advanced biomimetic hydrogel holds tremendous potential for applications in electronic skin (e-skin), human-machine interfaces (HMIs), and healthcare assessment devices.

Active and passive infrared emittance tuning using optically transparent unpatterned ITO thin films

Tailoring of thermal emittance has applications in smart radiators, camouflage, infrared (IR) scene generation, stealth, and thermal management. Various studies have explored avenues to achieve both passive and active emittance tuning using methods such as meta-surfaces, phase change materials, composites, nanostructure arrays and multi-layer stacks. Most of these methods often involve complex fabrication processes like multilayer depositions and micro/nano patterning, limiting their scalability for large-scale applications. This study presents a straightforward and scalable approach for passive and active emittance tuning using Indium Tin Oxide (ITO) films deposited on a high emissivity flexible polyethylene terephthalate (PET) substrate. By changing the deposition time, the thickness of the ITO film is controlled which changes the observed emissivity of the ITO/PET composite structure over a wide range (0.2–0.94) while maintaining optical transparency. Using this approach for passive emittance tuning, we demonstrate an IR scene generation application. As the ITO film is conducting, by applying voltage to the ITO/PET sheet, its temperature is changed using which active emittance tuning is also achieved. Compared to existing methods of emittance tuning, the presented approach is simpler, gives flexible films with optical transparency, and has the potential for large-scale integration, enabling cost-effective and scalable manufacturing of emittance-tuned surfaces.

TexSe1-x Shortwave Infrared Photodiode Arrays with Monolithic Integration.

TexSe1-x shortwave infrared (SWIR) photodetectors show promise for monolithic integration with readout integrated circuits (ROIC), making it a potential alternative to conventional expensive SWIR photodetectors. However, challenges such as a high dark current density and insufficient detection performance hinder their application in large-scale monolithic integration. Herein, we develop a ZnO/TexSe1-x heterojunction photodiode and synergistically address the interfacial elemental diffusion and dangling bonds via inserting a well-selected 0.3 nm amorphous TeO2 interfacial layer. The optimized device achieves a reduced dark current density of -3.5 × 10-5 A cm-2 at -10 mV, a broad response from 300 to 1700 nm, a room-temperature detectivity exceeding 2.03 × 1011 Jones, and a 3 dB bandwidth of 173 kHz. Furthermore, for the first time, we monolithically integrate the TexSe1-x photodiodes on ROIC (64 × 64 pixels) with the largest-scale array among all TexSe1-x-based detectors. Finally, we demonstrate its applications in transmission imaging and substance identification.

Coordinated frequency control strategy for modern power system considering engagement willingness

The large scale integration of renewable energy sources (RES) is posing unprecedented challenges to the frequency stability of modern power systems, with system inertia being the primary concern. Under such a landscape, this paper introduces a coordinated control strategy aiming at enhancing frequency stability by swiftly adjusting the power output of flexible resources to mitigate power imbalances and further dampen frequency fluctuations. Firstly, a communication-free center of inertia (COI) frequency estimation method is proposed. An equivalent inertia estimation method tailored for modern power systems is then developed by exploiting the correlation between synchronous inertia and active power fluctuations. By integrating the COI frequency variation rate with the estimated equivalent inertia, the imbalance power is calculated and compensated through the proposed coordinated control strategy. In this work, two typical flexible resources including photovoltaic (PV) generation and electric vehicles (EVs) are modeled and integrated into the testing system in PSCAD/EMTDC. Considering the contradiction between maximizing generation profit and reducing power output to mitigate frequency variation, the Corporate Social Responsibility (CSR) of renewable Generation Companies (GENCOs) is modeled to sketch their willingness of engaging into frequency support. Moreover, the frequency modulation potential of EVs in both commercial and residential areas are quantified for practical implementation. The simulations results successfully validate the effectiveness of the proposed control strategy.

Coordinated Control of Transient Voltage Support in Doubly Fed Induction Generators

The large-scale integration of wind power significantly alters the voltage dynamic characteristics of power systems. Wind turbines have a weak ability to withstand grid disturbances and have difficulty in providing effective reactive power support during transient periods. The sensitivity of wind turbines to the grid voltage significantly increases the probability of large-scale, cascading off-grid events. This paper proposes a coordinated control strategy to enhance the transient reactive power support capability of doubly fed wind farms. The additional stator current demagnetization control reduces the risk of a crowbar protection action after a fault and ensures that the unit power is controllable. Based on the voltage–reactive power coupling relationship, each unit can produce reactive power according to the voltage–reactive power sensitivity matrix during the transient period. After the reactive power output of the unit reaches the limit, transient active and reactive combined control is further adopted to reduce the active power output of the unit to a certain extent and improve the reactive power support capability. Finally, two cases are built in the PSCAD to verify the effectiveness of the proposed control strategy. The results show that the proposed control strategy can enable the wind farm to output more reactive power to the grid during the transient period, effectively supporting the system voltage during the transient process and avoiding further deterioration of the fault.

Coordination of Renewable Energy Integration and Peak Shaving through Evolutionary Game Theory

This paper presents a novel approach to optimizing the coordination between renewable energy generation enterprises and power grid companies using evolutionary game theory. The research focuses on resolving conflicts and distributing benefits between these key stakeholders in the context of large-scale renewable energy integration. A theoretical model based on replicator dynamics is developed to simulate and analyze the evolutionary stable strategies of power generation enterprises and grid companies with particular emphasis on peak shaving services and electricity bidding. These simulations are based on theoretical models and do not incorporate real-world data directly, but they aim to replicate scenarios that reflect realistic behaviors within the electricity market. The model is validated through dynamic simulation under various scenarios, demonstrating that the final strategic choices of both thermal power and renewable energy enterprises tend to evolve towards either high-price or low-price bidding strategies, significantly influenced by initial system parameters. Additionally, this study explores how the introduction of peak shaving compensation affects the coordination process and stability of renewable energy integration, providing insights into improving grid efficiency and enhancing renewable energy adoption. Although the results are simulation-based, they are designed to offer practical recommendations for grid management and policy development, particularly for the integration of renewable energies such as wind power in competitive electricity markets. The findings suggest that effective government regulation, alongside well-designed compensation mechanisms, can help establish a balanced interest distribution between stakeholders. By offering a clear framework for analyzing the dynamics of renewable energy integration, this work provides valuable policy recommendations to promote cooperation and stability in electricity markets. This study contributes to the understanding of the complex interactions in the electricity market and offers practical solutions for enhancing the integration of renewable energy into the grid.

Deep Immunoprofiling of Large-Scale Tuberculosis Dataset at Single Cell Resolution Reveals a CD81bright γδ T Cell Population Associated with Latency.

Tuberculosis (TB) remains one of the leading causes of death among infectious diseases, with 10.6 million new cases and 1.3 million deaths reported in 2022, according to the most recent WHO report. Early studies have shown an expansion of γδ T cells following TB infection in both experimental models and humans, indicating their abundance among lung lymphocytes and suggesting a role in protective immune responses against Mycobacterium tuberculosis (M. tuberculosis) infection. In this study, we hypothesized that distinct subsets of γδ T cells are associated with either protection against or disease progression in TB. To explore this, we applied large-scale scRNA-seq and bulk RNA-seq data integration to define the phenotypic and molecular characteristics of peripheral blood γδ T cells. Our analysis identified five unique γδ T subclusters, each with distinct functional profiles. Notably, we identified a unique cluster significantly enriched in the TCR signaling pathway, with high CD81 expression as a conserved marker. This distinct molecular signature suggests a specialized role for this cluster in immune signaling and regulation of immune response against M. tuberculosis. Flow cytometry confirmed our in silico results, showing that the mean fluorescence intensity (MFI) values of CD81 expression on γδ T cells were significantly increased in individuals with latent TB infection (TBI) compared to those with active TB (ATB). This finding underscores the importance of CD81 and its associated signaling mechanisms in modulating the activity and function of γδ T cells under TBI conditions, providing insights into potential therapeutic targets for TB management.

Imaging of Volatile Organic Compounds Using a Single Nanowire-Based Electronic Nose for Future Biomedical Applications.

This study introduces an array of semiconductor oxide single nanowires fabricated using advanced semiconductor processing techniques, including electron beam lithography and thin-film deposition, which is well-suited for large-scale nanowire integration. A four-channel nanowire array consisting of tin oxide (SnO2), indium oxide (In2O3), ferric oxide (Fe3O4), and titanium oxide (TiO2) was developed. As a proof of concept, we converted the response curves of the sensor array to heat maps, enabling comprehensive feature representation. The fabricated electronic nose (E-nose) was utilized to detect three types of volatile organic compounds (VOCs), with the results visualized in a heat map format. Additionally, the performance of each individual sensor was quantitatively studied, highlighting the array's potential for enhanced gas detection and analysis. To further illustrate the interaction between gas molecules and the nanowires, we visualized the gas response results by mapping the sensor's signal changes. These visualizations provide a clear representation of how different gas molecules interact with specific nanowires. For example, the heat maps reveal distinct response patterns for each type of VOC, allowing for the identification and differentiation of gases based on their unique signatures. This visualization technique not only enhances the understanding of gas-nanowire interactions but also demonstrates the effectiveness of the E-nose in distinguishing between various VOCs. The SnO2 nanowire gas sensor showed enhanced gas response compared to other materials. The SnO2 and TiO2 gas sensors showed enhanced response (62 and 56 s) and recovery times (100 and 37 s).

High-performance single-crystalline In2O3 field effect transistor toward three-dimensional large-scale integration circuits

Formation of a single crystalline oxide semiconductor on an insulating film as a channel material capable of three-dimensional (3D) stacking would enable 3D very-large-scale integration circuits. This study presents a technique for forming single-crystalline In2O3 having no grain boundaries in a channel formation region on an insulating film using the (001) plane of c-axis-aligned crystalline indium gallium zinc oxide as a seed. Vertical field-effect transistors using the single-crystalline In2O3 had an off-state current of 10−21 A μm−1 and electrical characteristics were improved compared with those using non-single-crystalline In2O3: the subthreshold slope was improved from 95.7 to 86.7 mV dec.−1, the threshold voltage showing normally-off characteristics (0.10 V) was obtained, the threshold voltage standard deviation was improved from 0.11 to 0.05 V, the on-state current was improved from 22.5 to 28.8 μA, and a 17-digit on/off ratio was obtained at 27 °C.

Numerical simulation of electrically-pumped overgrown III-V microwire lasers on silicon

Electrically-pumped III-V lasers on Si by aspect ratio trapping (ART) techniques have been a promising candidate for Si-based light sources. Although the lasers based on the ART approach enable large-scale integration and are compatible with complementary metal-oxide semiconductor processes, the sub-micron size laser structure suffers from severe metal absorption loss and heat accumulation. In this paper, we propose a novel Si-based III-V multi-quantum well laser by ART methods. The overgrowth of III-V microwires is adopted, with additional {110} quantum wells (QWs) generated during epitaxy. Through numerical simulation, the mode loss of the overgrowth structure is reduced from 3.59 dB/cm to 0.96 dB/cm, the threshold current is decreased by 42.5% and the output power is increased by 91.7% under pulsed conditions. Due to the growth of QWs on {110} planes, the injection efficiency of the device increases, leading to an improvement of performance. The effects of temperature and cavity length on the lasing characteristics of the device under continuous wave (CW) conditions are also analyzed that the proposed structure can realize CW lasing at room temperature. Moreover, the device deterioration caused by growth defects is discussed, which can be improved by high reflection coating. The suggested Si-based overgrowth III-V microwire laser has great potential to integrate high-density electrically-pumped light sources for silicon photonics.

Design and analysis of low power sense amplifier for static random access memory

<p>Today’s era is a digital world where each and every section of the society is experiencing and encountering with semiconductor chips. In very large-scale integration (VLSI) circuits the design of static random-access memory (SRAM) plays a crucial role in ensuring both low-power consumption and high-speed performance. The sense amplifiers (SA) are integral parts for information accessing storage in SRAM IC design. This paper introduces a dual voltage latch sense amplifier (DVLSA) for SRAM integrated circuits (IC). The comparative analyses of various SA are studied and then design a low-power SA through the implementation of energy-efficient technique. Further, we have elucidated the causes of delay and power dissipation in different SA with useful solutions and performance evaluation is conducted by comparing the proposed design with existing SA reported in the literature. The performance parameters such as power 1.604 uw, energy 470.50 fJ, delay 80.04 ps, and current 5.406 are scrutinized to assess the efficiency of the designs. The cell outcomes have been validated with cadence tool on 180 nm technology and operate at 1.8 V. The proposed design, namely, DVLSA demonstrates minimal energy consumption and low power dissipation, making it a promising advancement in SRAM IC technology.</p>

HVdc Grids for Large-Scale Offshore Wind Integration: Coordinating Offshore HVdc Grid Design with Onshore ac Grid Operation

HVdc Grids for Large-Scale Offshore Wind Integration: Coordinating Offshore HVdc Grid Design with Onshore ac Grid Operation

Ultrahigh Responsivity and Robust Semiconducting Fiber Enabled by Molecular Soldering-Governed Defect Engineering for Smart Textile Optoelectronics.

Semiconducting fibers (SCFs) are of significant interest to design next-generation wearable and comfortable optoelectronics that seamlessly integrate with textiles. However, the practical applications of current SCFs are always limited by poor optoelectronic performance and low mechanical robustness caused by uncontrollable multiscale structural defects. Herein, a versatile in situ molecular soldering-governed defect engineering strategy is proposed to construct ultrahigh responsivity and robust wet-spun MoS2 SCFs, by using a π-conjugated dithiolated molecule to simultaneously patch microscale sulfur vacancies within MoS2 nanosheets, diminish mesoscale interlayer voids/wrinkles, promote macroscale orientation, build long-range photoelectron percolation bridges, and provide n-doping effect. The derived MoS2 SCFs exhibit over two orders of magnitude higher responsivity (144.3 A W-1) than previously reported fiber photodetectors, 37.3-fold faster photoresponse speed (52ms) than pristine counterpart, and remarkable bending robustness (retain 94.2% of the initial photocurrent after 50000 bending-flattening cycles). Such superior robustness and photodetection capacity of MoS2 SCFs further enable large-scale weaving of reliable smart textile optoelectronic systems, such as direction-identifiable wireless light alarming system, modularized mechano-optical communication system, and indoor light-controlled IoT system. This work offers a universal strategy for the scalable production of mechanically robust and high-performance SCFs, opening up exciting possibilities for large-scale integration of wearable optoelectronics.

Optimizing resilience in large-scale integration of renewable energy sources: Exploring the role of STATCOM device

Optimizing resilience in large-scale integration of renewable energy sources: Exploring the role of STATCOM device

Parameter Identification of PMSG-Based Wind Turbine Based on Sensitivity Analysis and Improved Gray Wolf Optimization

With the large-scale integration of wind power, it is essential to establish an electromagnetic transient (EMT) model of a wind turbine system. Focusing on the problem of the difficulty in obtaining the parameters of the direct-driven permanent magnet synchronous generator (PMSG) model, this manuscript proposes a method based on trajectory sensitivity analysis and improved gray wolf optimization (IGWO) for identifying the parameters of the PMSG EMT model. First, a model of a PMSG wind turbine is established on an EMT simulation platform. Then, the key parameters of the model are determined based on the sensitivity analysis. Five control parameters are selected as the key parameters for their higher sensitivity indexes. Finally, the key parameters are accurately identified, using the proposed IGWO algorithm. The final case study demonstrates that the proposed IGWO algorithm has better optimization performance compared with the GWO algorithm and particle swarm optimization (PSO) algorithm. In addition, the simulation waveforms show that the identified parameters are accurate and applicable to other operating conditions.

Experimental demonstration of a silicon nanophotonic antenna for far-field broadened optical phased arrays

Optical antennas play a pivotal role in interfacing integrated photonic circuits with free-space systems. Designing antennas for optical phased arrays ideally requires achieving compact antenna apertures, wide radiation angles, and high radiation efficiency all at once, which presents a significant challenge. Here, we experimentally demonstrate a novel ultra-compact silicon grating antenna, utilizing subwavelength grating nanostructures arranged in a transversally interleaved topology to control the antenna radiation pattern. Through near-field phase engineering, we increase the antenna’s far-field beam width beyond the Fraunhofer limit for a given aperture size. The antenna incorporates a single-etch grating and a Bragg reflector implemented on a 300-nm-thick silicon-on-insulator (SOI) platform. Experimental characterizations demonstrate a beam width of 44°×52° with −3.22 dB diffraction efficiency, for an aperture size of 3.4 μm×1.78 μm. Furthermore, to the best of our knowledge, a novel topology of a 2D antenna array is demonstrated for the first time, leveraging evanescently coupled architecture to yield a very compact antenna array. We validated the functionality of our antenna design through its integration into this new 2D array topology. Specifically, we demonstrate a small proof-of-concept two-dimensional optical phased array with 2×4 elements and a wide beam steering range of 19.3º × 39.7º. A path towards scalability and larger-scale integration is also demonstrated on the antenna array of 8×20 elements with a transverse beam steering of 31.4º.

How to choose mobile energy storage or fixed energy storage in high proportion renewable energy scenarios: Evidence in China

With the large-scale integration of renewable energy and changes in load characteristics, the power system is facing challenges of volatility and instability. Therefore, enhancing the safe and stable operation capability of the power system is an urgent problem that needs to be solved. Mobile energy storage can improve system flexibility, stability, and regional connectivity, and has the potential to serve as a supplement or even substitute for fixed energy storage in the future. However, there are few studies that comprehensively evaluate the operational performance and economy of fixed and mobile energy storage systems. To comprehensively evaluate the economic benefits of large-scale mobile energy storage systems, this paper constructs an overall horizontal cost model for energy storage systems that considers the power system and train transportation system. This model not only introduces the traditional concept of lifecycle cost of energy storage systems, but also considers the costs of traditional transmission lines and battery transportation. Secondly, to achieve simulation of large-scale mobile energy storage system planning and operation, this paper establishes a multi-region power planning and operation simulation (MPO) model and a battery transportation and logistics (BTL) model to accurately reflect the operation mode of fixed energy storage and mobile energy storage in the power system. Finally, taking the actual power grids and railway networks in Northeast and North China as case studies, this article provides an in-depth analysis of the technical, economic, and environmental performance of large fixed and mobile energy storage systems, and conducts a detailed comparison. The research results indicate that under high grid connection ratios (using 75% and 66% as examples), the overall cost of mobile energy storage systems continues to decrease to 1.42 CNY/kWh and 0.98 CNY/kWh. Compared to fixed energy storage at 5.45 CNY/kWh and 4.79 CNY/kWh, it has an absolute economic advantage and shows significant carbon reduction capabilities, reaching 241,800 to 1,394,600 tons. This discovery fully confirms the enormous potential and application value of mobile energy storage in high proportion renewable energy scenarios, providing strong technical support and economic analysis basis for the sustainable development of the power system.

Large-scale integration of MoS2 on high-TC superconducting YBa2Cu3O7 for the realization of Josephson devices

Large-scale integration of MoS2 on high-TC superconducting YBa2Cu3O7 for the realization of Josephson devices

Optimizing VLSI Design Verification with Histogram-Based Difference Algorithm

Abstract: This research explores the optimization of Very Large Scale Integration (VLSI) plan confirmation utilizing the Histogram-Based Distinction Calculation (HBDA) and compares its execution with conventional calculations. Through comprehensive tests, HBDA illustrates predominant confirmation speed, precision, and asset utilization compared to ordinary strategies such as Exhaustive Comparison Algorithm (ECA), Cross-Correlation Calculation (CCA), and Energetic Time Twisting Calculation (DTWA). Particularly, HBDA accomplishes a normal confirmation speed of 25 milliseconds, with a precision of 98.5% and asset utilization of 75%. In differentiation, ECA shows slower confirmation speed (150 milliseconds) and higher asset utilization (100%), whereas CCA and DTWA appear halfway in execution in terms of speed, exactness, and asset utilization. The related work survey highlights different inventive strategies in VLSI plan and optimization, counting neuromorphic computing, vitality gathering, and IoT frameworks. By and large, this research contributes to progressing VLSI plan confirmation techniques, advertising a more effective and solid approach to guarantee the usefulness and unwavering quality of cutting-edge electronic frameworks.

Thin film ferroelectric photonic-electronic memory

To reduce system complexity and bridge the interface between electronic and photonic circuits, there is a high demand for a non-volatile memory that can be accessed both electrically and optically. However, practical solutions are still lacking when considering the potential for large-scale complementary metal-oxide semiconductor compatible integration. Here, we present an experimental demonstration of a non-volatile photonic-electronic memory based on a 3-dimensional monolithic integrated ferroelectric-silicon ring resonator. We successfully demonstrate programming and erasing the memory using both electrical and optical methods, assisted by optical-to-electrical-to-optical conversion. The memory cell exhibits a high optical extinction ratio of 6.6 dB at a low working voltage of 5 V and an endurance of 4 × 104 cycles. Furthermore, the multi-level storage capability is analyzed in detail, revealing stable performance with a raw bit-error-rate smaller than 5.9 × 10−2. This ground-breaking work could be a key technology enabler for future hybrid electronic-photonic systems, targeting a wide range of applications such as photonic interconnect, high-speed data communication, and neuromorphic computing.