Nanoscale Horizons最新文献

Micro/nanorobots have attracted much attention because of their potential to perform complex tasks with high precision under controlled actuation within the human body, such as targeted cargo delivery, lesion exploration, and minimally invasive surgery. Among the various emerging fabrication technologies, multidimensional additive manufacturing (MAM) technology can enable the design and fabrication of complex structures with multifunctional characteristics. Compared with traditional manufacturing methods, MAM significantly reduces production complexity and time while enhancing design flexibility and customization. This review provides a comprehensive overview of MAM technologies for constructing micro/nanorobots, along with their applications and associated challenges in the biomedical field. In addition, emerging MAM approaches, including 4D, 5D, and 6D printing assisted by physical intelligence, machine learning, and artificial intelligence show great potential for designing and fabricating more sophisticated and intelligent micro/nanorobots, thereby advancing their clinical translation in the near future.

Efficient recycling of spent lithium-ion batteries (LIBs) is pivotal for mitigating the looming shortage of critical metals and the environmental burden posed by the massive accumulation of battery waste. However, conventional pyrometallurgical and hydrometallurgical processes are often constrained by their reliance on inert atmospheres and sluggish leaching kinetics. Herein, we propose a Laser-induced Carbothermal Reduction (LCTR) strategy for the low-carbon recovery of spent cathodes and demonstrate a synergistic mechanism that couples micro-morphological restructuring with lattice defect engineering. Laser-induced transient thermal shock triggers the stress-driven pulverization of secondary particles, increasing the specific surface area, while simultaneously reducing high-valence transition metals and generating oxygen vacancies. This dual modification enables rapid dissolution kinetics (15 min) in mild acid (0.5 M H₂SO₄), achieving a lithium recovery rate of 99.72% and >90% for transition metals. Furthermore, the process exhibits broad universality across diverse cathode chemistries (including NCM series, LiCoO₂, and LiMn₂O₄) and authentic spent electrodes. This study not only elucidates the microscopic mechanisms of laser-matter interaction but also presents a high-throughput, economically viable paradigm for sustainable urban mining.

Nonlocal metasurfaces extend the capabilities of flat optics by exploiting collective, spatially extended electromagnetic modes that enable momentum-dependent control of light within an ultrathin platform. When combined with electrical tunability, such metasurfaces move beyond static wavefront shaping toward dynamic, programmable manipulation of optical fields. In this Focus Article, we review recent advances in electrically controlled nonlocal metasurfaces, highlighting the physical mechanisms that underpin nonlocal responses, including coupled-resonator networks, guided-mode resonances, and surface lattice resonances. We discuss how electrical control based on carrier modulation, phase-change materials, and electro-optic effects enables dynamic tuning of phase, amplitude, and wavevector, and how resonant nonlocal architectures enhance otherwise weak modulation strengths. Finally, we examine emerging spatiotemporal nonlocal metasurfaces that combine collective momentum-dependent responses with ultrafast electrical modulation, enabling frequency-momentum conversion, adaptive wave-based signal processing, and nonreciprocal optical functionalities. Together, these developments point toward a new generation of reconfigurable, ultrathin photonic systems that compress complex optical operations into a single electrically programmable interface.

Our Emerging Investigator Series features exceptional work by early-career nanoscience and nanotechnology researchers. Read Wouter Van Gompel's Emerging Investigator Series article 'Ultrafast charge transfer and coherent phonons in electroactive organic cation-templated low-dimensional perovskite analogues' (https://doi.org/10.1039/D5NH00494B) and read more about him in the interview below.

Proton exchange membrane water electrolysis is a key technology for sustainable hydrogen production, yet its widespread deployment is severely constrained by the reliance on scarce and expensive iridium-based oxygen evolution reaction (OER) catalysts. Ru oxide-based catalysts have emerged as a promising alternative owing to their intrinsically high OER activity and relatively lower cost. However, their practical application is fundamentally limited by rapid degradation under acidic and highly oxidative conditions. This instability originates from the intrinsic coupling between lattice-oxygen-driven reaction pathways, cation demetallation, and dynamic structural reconstruction during oxygen evolution. In this review, we present a mechanistic overview of dopant-driven strategies for stabilizing Ru-based electrocatalysts under water electrolysis. We summarize how dopant incorporation modulates Ru-O bonding, lattice oxygen reactivity, and reaction pathway selection, thereby suppressing Ru dissolution and structural collapse. Dopant effects are discussed in terms of lattice and phase stabilization as well as electronic and chemical modulation, encompassing substitutional, interstitial, and atomically dispersed dopants. By correlating mechanistic insights from operando spectroscopy and dissolution analyses with reported durability trends, this review establishes dopant engineering as a unifying design framework for reconciling activity and stability in Ru-based oxygen evolution catalysts.

Evaporation continuously converts absorbed solar heat into the kinetic motion of water molecules, creating a ubiquitous driving force that remains largely untapped for direct electricity generation. In plants, this process is harnessed through transpiration, where capillary flow and sustained negative pressure drive long-range water transport without moving parts. Inspired by this natural hydraulic engine, transpiration-inspired hydrovoltaics (TIH) have emerged as solid-state material platforms that convert evaporation-driven water transport into electrical output through interfacial electrokinetic processes. In this review, we introduce a unified physical framework for TIH by explicitly connecting the physics of plant transpiration to evaporation-driven electricity harvesting in engineered porous media. We summarize the governing principles of water ascent in trees, including capillarity, water-potential gradients and cohesion-tension stability, and map these concepts onto synthetic TIH architectures built from hydrophilic micro- and nanofluidic networks. We critically examine the proposed electricity-generation mechanisms in TIH, including classical streaming potentials on insulating substrates, pseudo-streaming in conductive porous networks and ionovoltaic coupling in semiconducting channels. We systematically elucidate how geometry, pore microarchitecture, surface chemistry, electrical conductivity and environmental conditions such as humidity, temperature and airflow jointly govern device performance. By benchmarking TIH against decades of quantitative insight from plant hydraulics, we identify key trade-offs, unresolved mechanistic questions, and actionable design opportunities for robust, scalable evaporation-driven power generation and self-powered sensing. Together, these perspectives position TIH as a promising platform for distributed energy harvesting at the water-energy nexus.

Immunoassay methods such as enzyme-linked immunosorbent assay using antigen-antibody reactions have been applied to detect biomarker proteins in the case of various diseases (e.g., cancer). However, these methods comprise several-hour-long pre-treatment processes (incubation and washing) before detection, and their sensitivity is limited by the affinity of protein and antibody sets. Here, we demonstrate the rapid and highly sensitive analysis of a cancer biomarker at several hundreds of attograms using a microflow-type light-induced acceleration system (MF-LAC-SYS) to enhance the reaction between the multiple antibodies and glycoprotein (CEACAM-5) from human plasma containing multiple impurities with the help of theoretical analysis. Adjusting the surface charge of the antibody-modified beads and buffer solution components, we could detect pg mL^-1 levels of CEACAM-5 at high sensitivity under a laser beam irradiation of several hundred mW for several minutes at a defocused condition equivalent to the microchannel width. Specifically, we discovered the existence of nanoscale CEACAM-5 aggregates related to the sensitivity of the MF-LAC-SYS, using dynamic light scattering and electron microscopy. The results will potentially pave the way for a platform using unconventional immunoassays for liquid biopsy and blood proteomics.

Humidity sensors, as key electronic devices for monitoring humidity, have a wide range of applications, including environmental and human-related humidity detections. Paper has become a promising material for flexible humidity sensors due to its inherent advantages such as low cost, hydrophilicity, environmental friendliness and flexibility. After years of development, paper-based humidity (PBH) sensors have made significant achievements, but many challenges remain in this field. This review aims to systematically discuss the recent developments in PBH sensors (mainly focusing on the past 5 years). First, we overview the main performance parameters and test methods of humidity sensors. Then, the fabrication techniques, as well as the humidity sensing mechanisms and performances of different types of PBH sensors (resistance, capacitance, impedance, triboelectricity, electrochemical, and ion-gradient), are systematically reviewed and discussed. In addition, the emerging applications of PBH sensors for human-related humidity detection are discussed. Finally, the challenges and future trends of PBH sensors are analyzed from different aspects. We hope that this review will provide important insights and guidance for the development of PBH sensors.

The superb detection sensitivity of interferometric scattering (iSCAT) microscopy enables a high-speed optical read-out of individual dimers of DNA-tethered noble metal nanoparticles (NPs), so called Plasmon Rulers. The iSCAT contrast of Plasmon Rulers depends on their structure, and fluctuations of the iSCAT contrast may provide insight into the conformational dynamics of the tether molecule. In this work, heterodimer Plasmon Rulers are assembled from 40 and 20 nm diameter Au NPs using a switchable DNA tether. The tether contains a central molecular beacon hairpin sequence that opens upon binding of the micro-RNA (miRNA) 574-3P (M_W = 6582.3 Da). The 40 nm NP of the heterodimers is immobilized on a glass support, while the 20 nm NP is left to perform a tethered particle diffusion. The iSCAT contrast of individual heterodimers is collected before and after exposure to miRNA with an acquisition rate of 50 kHz. Binding of the 22 nucleotides long target miRNA to the molecular beacon segment increases the accessible conformational space of the tethered 20 nm NP. The resulting gain in conformational variability of the heterodimer is detected as a significant increase in the mean absolute deviation (MAD) of the iSCAT contrast. These findings confirm that iSCAT fluctuation microscopy of the heterodimer Plasmon Rulers can detect conformational changes in the tether molecule and pave the path to monitoring the conformational dynamics of individual biopolymers.

Spin-torque nano-oscillators (STNOs) are promising nanoscale microwave oscillators for applications in wireless communication and neuromorphic computing. Although simulations suggest that STNOs with tilted magnetic anisotropy (TMA) can deliver superior performance, experimental investigations-especially those employing TMA free layers-remain unreported. Here, we experimentally investigate nanocontact STNOs (NC-STNOs) incorporating a TMA free layer based on a [Co/Pd]/Cu/[Co/Ni]/NiFe multilayer structure. By integrating experimental measurements with micromagnetic simulations, we uncover rich magnetization dynamics that are inaccessible in conventional anisotropy systems. Notably, we observe the coexistence and transition between distinct dynamical modes, which give rise to multi-frequency microwave emission. In addition, we identify a unique droplet-like propagating spin-wave (PSW) mode that simultaneously exhibits characteristics of both magnetic droplets and PSW. Most importantly, this droplet-like PSW mode enables synchronization over significantly greater distances compared to perpendicular magnetic anisotropy (PMA)-based STNOs, highlighting its potential for large-scale mutual synchronization. These findings advance the understanding of magnetization dynamics in TMA systems and establish a pathway toward synchronized STNO arrays for practical applications.