Nano Convergence最新文献

In this study, we demonstrated the nanostructuring of the ferroelectric (FE) phase of Pb(Zr_0.95Ti_0.05)O₃ (PZT-95/5) into a thick film with relaxor-like FE (RFE) characteristics. This transformation results in exceptionally high dielectric breakdown strength (E_DBS) and energy storage density properties. The high kinetic energy from aerosol deposition transformed the bulk PZT-95/5 from a normal FE system into a RFE system by forming a nanostructured grain with nanodomains within a nonpolar matrix. This nanostructure enables easy domain switching, resulting in low remanent polarization. The resulting high density of grain boundaries due to nanograin formation and the nonpolar structure act as barriers to charge flow, resulting in high breakdown strength. Collectively, these effects resulted in a significantly enhanced E_DBS of 5.6 MV/cm and a maximum polarization of 80 µC/cm². These properties, evidenced by slim hysteresis loops, demonstrate that the prepared PZT-95/5 thick film is a superior capacitive material with a high recoverable energy density of 116 J/cm³. Furthermore, the film exhibited reliable fatigue endurance up to 10⁷ cycles and thermal stability from room temperature to 140^°C. The film also exhibited a peak power density of 35 MW/cm³ under a practical electric field of 0.45 MV/cm (180 V) and a fast discharging speed (τ_0.9) of 230 ns. These properties, in addition to the minimal fabrication steps and superior capacitive characteristics, demonstrate the strong potential of the prepared PZT-95/5 thick film for use in next-generation energy storage devices.

Living cells produce nanometer scales of extracellular vesicles (EVs) that have attracted considerable interest due to their transformative effects on diagnostics and therapies for cancer and other diseases. While significant advancements have been made in grasping the physical and chemical foundations of separation techniques for EVs, challenges must be overcome to ensure effective EV purification for diverse life sciences and clinical applications. This review highlights the most significant developments in efficient isolation and purification methods for EVs in transformative medicine. We examine the basic structure of exosomes and how to obtain specimens containing exosomes and EVs from various body fluids. We investigate the principles of physical, chemical, and biological isolation methods of EVs. We systematically evaluate different designs of microfluidics-based EV purification methods. We provide a comprehensive overview of the applications of exosomes in the life sciences and medicine. The precise engineering of EV isolation and purification generates a high yield and purity, offering practical solutions for translational medicine.

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By precisely timed optical excitation of their spin, optical emitters such as semiconductor quantum dots or atoms can be harnessed as sources of linear photonic cluster states. This significantly reduces the required resource overhead to reach fault-tolerant optical quantum computing. Here, we develop an algorithm that analytically tracks the global density matrix through the process of the protocol for generating linear-cluster states by Lindner and Rudolph. From this we derive a model to calculate the entangling gate fidelity and the state fidelity of the generated linear optical cluster states. Our model factors in various sources of error, such as spin decoherence and the finite excited state lifetime. Additionally, we highlight the presence of partial reinitialization of spin coherence with each photon emission, eliminating the hard limitation of coherence time. Our framework provides valuable insight into the cost-to-improvement trade-offs for device design parameters as well as the identification of optimal working points. For a combined state-of-the-art quantum dot with a spin coherence time of ({T}_{2}^{*}=535) ns and an excited state lifetime of (tau =23) ps, we show that a near-unity entangling gate fidelity as well as near-unity state fidelity for 3-photon and 7-photon linear cluster states can be reached.

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Olfactory display systems, designed to replicate the human sense of smell, rely on gas sensors that are fast, selective, and reliable. From this perspective, this review highlights recent progress in sensing materials and integration strategies that enable room-temperature operation, rapid response and recovery, and closed-loop control for realistic odor delivery. Advances are classified into three categories: organic, inorganic, and hybrid systems. Organic materials, including conductive polymers and biomolecules, offer tunable selectivity and lightweight flexibility. Inorganic semiconductors, especially metal oxides, provide high sensitivity and durability, though they typically require elevated temperatures. Hybrid architectures, exemplified by M13 bacteriophage–carbon nanotube composites, merge these strengths to achieve superior performance under ambient conditions. Particular emphasis is placed on sensors for ethylene, hydrogen sulfide, hydrogen, acetone, and nitrogen dioxide—gases critical to food preservation, environmental monitoring, and healthcare. Finally, we discuss persistent challenges, such as selectivity under complex conditions, device miniaturization, and closed-loop integration, and propose strategic research directions toward immersive, real-time olfactory display technologies.

This study investigates the influence of sputtering plasma-induced damage on stochastic characteristics in HfZrO₂ (HZO)-based ferroelectric tunnel junctions (FTJs), with an emphasis on memory and neuromorphic device optimization. Variation of the sputtering plasma power during top electrode deposition introduces distinct levels of trap within the HZO layer. Low-frequency noise (LFN) spectroscopy and temperature-dependent electrical measurements confirm that higher plasma power generates additional shallow-level traps, thereby promoting Poole-Frenkel conduction while simultaneously increasing current noise magnitude. Although the resulting enhancements in on-current density and ferroelectric tunnel electroresistance (TER) ratio are beneficial for high-density memory integration, these conditions also elevate stochastic fluctuations, potentially degrading read margins and long-term endurance. Furthermore, the observed increase in stochasticity negatively affects neuromorphic inference accuracy, particularly after endurance cycling stress. These results demonstrate the critical interplay among plasma process conditions, trap density, and LFN in FTJs. By systematically engineering sputtering process parameters, we optimize the electrical performance with minimized stochastic noise. This approach provides guidelines for the development of next-generation ferroelectric-based memories and neuromorphic systems with consideration of stochasticity, where robust performance and reliability are imperative for large-scale integration.

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Lead-free halide-perovskite memristors have advanced rapidly from initial proof-of-concept junctions to centimeter-scale selector-free crossbar arrays, maintaining full compatibility with CMOS backend processes. In these highly interconnected matrices, surface passivation, strain-relief interfaces, and non-toxic B-site substitutions successfully reduce sneak currents and stabilize resistance states. The Introduction section lays out the structural and functional basis, detailing phase behavior, bandgap tunability, and tolerance-factor-guided crystal design within Ruddlesden–Popper, Dion–Jacobson, vacancy-ordered, and double-perovskite frameworks, each of which is evaluated for its ability to confine filaments and reduce crosstalk in crossbar configurations. The following sections examine the characteristics of charge transport and the dynamics of ion migration, followed by a detailed outline of chemical and mechanical stabilization strategies in response to the high current densities and heat fluxes typical of large-area crossbars. The comparison of solution, vapor, and solid-state synthesis routes focuses on aspects such as film uniformity, grain-boundary control, and compatibility with flexible or heterogeneous substrates, all evaluated against the demanding uniformity requirements of multilevel crossbar programming. The principles of resistive switching and array architecture are elaborated upon, emphasizing the three-dimensional (3D) stacking of selector-integrated vertical nanowires and hybrid photonic-memristive layers as promising approaches to enhance bandwidth and reduce energy consumption per operation. By integrating sustainable chemistry with scalable crossbar engineering, these memories are set to provide ultra-dense, energy-efficient hardware that meets the performance demands of contemporary artificial intelligence accelerators while adhering to new regulations on hazardous materials in electronic devices.

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A surface-enhanced Raman scattering (SERS)-based aptasensor was developed for the rapid and sensitive detection of Escherichia coli (E. coli), a major pathogen in urinary tract infections (UTIs). The sensor utilizes magnetic beads embedded with gold nanoparticles (MB-AuNPs) functionalized with capture DNA (cDNA) as both the SERS-active substrate and magnetic separation tool. The detection mechanism relies on an aptamer DNA-probe DNA complex: when the aptamer binds specifically to E. coli, the probe DNA is released and subsequently hybridizes with cDNA on the MB-AuNPs. This brings a Cy5 Raman label close to the gold surface, generating a strong SERS signal. The assay offers a one-step process, eliminating the need for bacterial culture or nucleic acid amplification, and completes within approximately 6 h. Quantitative analysis demonstrated a detection limit of 5.9 × 10³ CFU/mL, well below the clinical threshold for UTIs, with a reliable calibration curve (R² = 0.990). Selectivity tests confirmed high specificity for E. coli without cross-reactivity to other bacteria. Clinical evaluation using 21 urine samples showed high diagnostic performance: 100% sensitivity, 91% specificity, 95% accuracy, and 100% precision compared to standard urine culture. These results highlight the aptasensor’s potential as a rapid, sensitive, and specific alternative for UTI diagnosis in clinical settings.

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MXenes, a versatile family of two-dimensional (2D) transition metal carbides and nitrides, have attracted significant attention for battery applications due to their exceptional properties, such as high electronic conductivity, tunable microstructure, robust mechanical and chemical stability, and compositional diversity. However, despite these advantages, conventional MXene synthesis methods-relying heavily on toxic acid etching-pose serious environmental hazards, undermining their suitability for sustainable energy applications. In this context, eco-friendly and non-toxic MXene synthesis routes have become increasingly critical for enabling the widespread adoption of MXene, driving extensive research into alternative, green synthetic approaches. These recent advances in environmentally benign synthesis are pivotal to unlocking the full potential of MXenes for diverse next-generation battery technologies. In this review, we provide a comprehensive overview of green and sustainable MXene synthesis strategies, highlighting the latest developments that go beyond traditional fluorine-based routes. Each synthetic process is comparatively analyzed with respect to its efficacy, limitations, and implications for practical application as key functional components in lithium-ion batteries (LIBs) and post-LIB systems. Finally, we offer a perspective on how the development of eco-friendly MXenes can contribute to overcoming the industrial challenges facing advanced battery technologies.

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Wide bandgap (WBG) power semiconductors have attracted significant attention from both academia and industry because they are superior to conventional silicon-based devices. In WBG power semiconductor packages, die attach materials play a crucial role in maximizing device performance and reliability. The die attach interfaces in WBG packages must withstand high operating temperatures (200–300 °C), fast switching frequencies, and great power densities while maintaining excellent thermomechanical reliability. Traditional die attach materials have significant limitations when applied to WBG devices, which has led to intensive research into nanomaterial-based alternatives during the past decade. This review summarizes current state-of-the-art nano-enabled die attach technologies: nanocomposite solders, nano-sintering approaches, and novel nanomaterial formulations specifically engineered for WBG power semiconductor packages. We examine the fundamental mechanisms behind the performance of nanomaterial die attach solutions and their ability to address the thermal management challenges of WBG devices. Furthermore, we examine the reliability of these materials in extreme operating conditions by evaluating their thermal cycling performance, shear strength stability, and microstructural evolution.

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Highly oriented oxide thin films hold substantial relevance to a wide range of fields. A major challenge is their integration with technological substrates, such as flexible polymers and silicon. While multiple strategies for the lift-off and transfer of high-quality oxide thin films have been widely explored, it remains a challenge to easily transfer films with low defect levels. In this work, we introduce a novel and effective strategy for achieving high-quality, freestanding perovskite oxide thin films. We first demonstrate that highly oriented perovskite oxides, as both single-phase films and vertically aligned nanocomposite (VAN) films, can be grown by pulsed laser deposition on single crystal NaCl, as not shown before. We next show that the VAN films, unlike single-phase films, can be readily, electrostatically, dry lifted-off the substrate. The success of the lift-off technique is enabled by (i) a high thermal expansion mismatch of the film, producing compression in the film, and (ii) lack of elastic strain relief in the out-of-plane direction in the VAN film. Finally, we show that a VAN cathode film can be incorporated into a proof-of-concept micro-solid oxide fuel cell structure, and that it is of good structural quality as demonstrated by performance comparable to equivalent VAN films grown on single crystal YSZ. Thus, we developed an entirely new way to lift-off and transfer highly oriented oxide thin films for use in a wide variety of electronic applications.

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