The challenge of dendrite growth limiting metal battery lifespan, despite extensive chemical composition optimizations for artificial solid electrolyte interphases (ASEIs), necessitates the development of ASEI design routes. Regulating the ASEI crystallographic microstructure offers a promising yet underexplored solution with efficacy uncertainty. Critical issue lies in what is the optimal crystallographic microstructure state. Using the ZnS ASEI in aqueous Zn batteries as a case study, here we report the effects of grain orientation and grain boundary density on the performance of Zn negative electrode. The results reveal the existence of an optimal microstructure state-predominant in-plane (111) orientation coupled with a critical grain boundary density of ~55 μm/μm2-which delivers an 18-fold lifespan extension, and over 3400 cycles with a Coulombic efficiency of 99.92% at 5 mA cm-2, surpassing the efficacy of most chemical composition manipulations. Mechanistically, the (111) orientation integrates higher electrochemical kinetics and mechanical strength. As grain boundary density increases to tens of μm/μm2, the enhancement in electrochemical kinetics coincides with compromised mechanical strength, with their trade-off delineating the critical density that maximizes electrode cycling stability. Our findings exemplify an efficient ASEI design route-crystallographic microstructure engineering.

Achieving structural materials that combine high strength, toughness, and sustainability remains a significant challenge in materials science and engineering. Wood, as a renewable and widely available natural resource, presents promising potential but is limited by its intrinsic anisotropy and mechanical property variations across directions. Inspired by the Bouligand architecture─composed of helicoidally stacked layers of aligned fibers─we developed a straightforward and effective approach to overcome these limitations. By exploiting the natural orientational alignment of wood fibers, we chemically treated the wood to expose hydroxyl groups of cellulose and then densified the wood by helicoidal stacking to obtain Bouligand wood. This bioinspired design yielded a wood-based material exhibiting in-plane isotropy alongside exceptional strength (∥235.2 MPa, ⊥203.9 MPa) and toughness (∥10.8 MPa·m1/2, ⊥15.3 MPa·m1/2), outperforming many commonly used polymers and metals. The helicoidal architecture facilitates crack deflection and bridging mechanisms, substantially enhancing toughness, while hydrogen bonding strengthens the cellulose network and improves interfacial adhesion. Integrating structural design with cellulose's inherent molecular interactions enabled us to significantly reduce wood's anisotropy and realize a novel, high-performance wood-based structural material with well-balanced mechanical properties. This sustainable, mechanically isotropic material offers considerable promise for applications in construction, automotive, aerospace, and other engineering fields.

Compared to ferroelectric ceramics, polymers exhibit lower flexoelectric coefficients but offer superior processability and flexibility, making them attractive for deformable electromechanical systems. Cellulose, a biodegradable and biocompatible polymer, is a promising candidate for materials with controllable flexoelectricity. Nevertheless, the intrinsic flexoelectric properties of cellulose remain unexplored, with key influencing mechanisms barely understood either. It is notable that cellulose exhibits a typical crystalline-amorphous dual-phase configuration, making polarization behavior in cellulose strongly depends on the proportion and microstructure of crystalline regions. Therefore, this work located crystallinity as a vital structural parameter in cellulose membrane and unraveled the regulation law of crystallinity on flexoelectric properties. As crystallinity in cellulose membranes increases, which is determined by three independent methods (Segal peak height method: 79.46%-91.37%; peak fitting method: 60.35%-73.09%; FTIR method: 23.21%-44.03%), the flexoelectric coefficient correspondingly rises from 7.33 +/- 2.01 to 22.25 +/- 1.35 nC/m, revealing a clear linear positive correlation. This trend is found to be independent of the dielectric and piezoelectric properties, suggesting a mechanism related to crystallinity-regulated variations in dipole reorientation. The cellulose membranes also display high mechanical properties, optical transparency, and shapeability. These findings elucidate the essential role of crystallinity in cellulose flexoelectricity and provide crucial insights for the design of high-performance sustainable flexible electronic devices.

The out-of-plane shear modulus of two-dimensional (2D) materials is critical for understanding their strain-modulated electronic, optical, and tribological behavior. However, existing experimental methods are limited and often yield inconsistent results due to substrate interference. Here, we introduce a contact-resonance-based methodology utilizing a probe–suspended membrane system to simultaneously measure both the out-of-plane shear modulus and in-plane prestress of 2D material membranes. The membrane's load–deflection response is modeled via a novel cubic equation fitted from numerical simulations. The probe–membrane dynamic system is modeled as a tilted cantilever with normal and lateral springs at its tip, yielding a frequency equation that links resonance frequency to membrane stiffness. Experimental measurements on suspended multilayer graphene under varying loads yield an out-of-plane shear modulus of 4.16 ± 0.30 GPa, consistent with theoretical predictions. The in-plane prestress is observed to decrease with membrane thickness. Pressure-blister tests corroborate that van der Waals attraction from the hole sidewalls is a primary origin of this prestress. This work establishes a precise, nondestructive method for characterizing 2D material mechanical properties with minimal substrate influence, offering fundamental insights for the design and performance evaluation of 2D material-based nanodevices and flexible systems.

Uranium dioxide (UO_2) serves as the predominant nuclear fuel globally. Despite its widespread application, evaluating its mechanical, thermophysical, and species transport behaviors under extreme accident scenarios remains a formidable challenge for conventional experimental and computational methods. To address this, we develop a versatile machine learning interatomic potential (MLIP) for UO_2 by proposing an efficient training strategy, termed the "FAST" (Fine-tuning via Active-learning and Superionic-Targeting) framework. Our "FAST" framework integrates superionic transition-targeted sampling with active learning-enhanced exploration to efficiently construct a highly compact dataset comprising only 500 configurations for fine-tuning a foundation model. By rigorously accounting for the strong correlation of uranium 5f electrons and antiferromagnetic (AFM) ground state during DFT labeling, we train a robust DFT-level neuroevolution potential (NEP) for UO_2. We demonstrate that this NEP exhibits superior predictive capability for various physical properties, encompassing mechanical, defect, thermophysical, and ionic diffusion over an extensive temperature range. Moreover, this NEP accurately captures the anomalous thermophysical and kinetic behaviors triggered by superionic transition. Specifically, it reproduces both the λ-peak in linear thermal expansion coefficient (LTEC) and "non-Arrhenius" anionic diffusion. Crucially, NEP-based simulations elucidate the microscopic origins underlying these anomalies: the pre-melting of oxygen sublattice and resultant kinetic decoupling between U and O ions.

This study investigates the size-dependent mechanical behavior of the HfNbTaTiZr refractory high-entropy alloy (RHEA) under uniaxial tension, with a focus on the effects of random solid-solution (RSS) and chemical short-range order (CSRO). A machine learning framework is developed to accelerate the parameterization of interatomic force fields (FFs), enabling molecular dynamics simulations of three nanocrystalline models: (i) a meta-atom (MA) mode representing the RHEA as a hypothetical sing-element system with averaged properties, (ii) a quinary RSS model with randomly distributed constituent atoms, and (iii) a Monte Carlo (MC) model with internal CSRO. The results reveal that RSS enhances strength, while CSRO reduces flow stress level but improves strain hardening and failure resistance. A transition from Hall-Petch (HP) strengthening to inverse Hall-Petch (IHP) softening is observed, with CSRO suppressing this transition. The underlying plastic mechanisms (i.e., dislocation slip, deformation twinning, phase transformation and grain boundary movements) are analyzed from both nanostructural and energetic perspectives. Theoretical models are established to describe the size-dependent yield strength and predict the critical grain size. Additionally, the contributions of different plastic mechanisms to the overall stress response are separately quantified. These findings provide new insights into the design and performance optimization of RHEAs through nanostructural engineering.

(U1 − x,Thx)O2, commonly known as the ThO2-based MOX, is a promising nuclear fuel candidate for various advanced reactors. A thorough understanding of its high-temperature creep behavior is demanding for assessing its fuel performance and predicting its service lifetime under normal operating and extreme accidental conditions. By utilizing the molecular dynamics simulations, we investigate the creep mechanisms and their transitions of nanocrystalline (U1 − x,Thx)O2 MOX affected by thorium contents, grain sizes, temperatures and stresses. We find that at lower temperatures and stresses, Coble creep is the dominant creep mechanism in nanocrystalline (U1 − x,Thx)O2, which is rate-limited by cation diffusion along grain boundaries. Beyond a critical stress, significant grain boundary sliding activates, causing a transition from the Coble creep to Lifshitz sliding-dominated creep. As temperature approaches the superionic transition temperature of nanocrystalline (U1 − x,Thx)O2, the pre-melting of its anionic sublattice leads to a marked enhancement in ionic diffusivity. Such enhancement in cationic diffusivity enables the cation to diffuse in lattice, thereby leading to a transition from Coble creep to Nabarro-Herring creep. The findings of this work not only provide valuable insights into the high-temperature creep behaviors of ThO2-based MOX fuels under extreme conditions but also shed light on the future design of fluorite-type fuels with tailored creep performance.

Dislocations are line defects in crystalline solids that strongly influence material behavior. While their role in mechanical properties of metals is well established, growing attention has recently turned to ceramics, where dislocations can also be harnessed to tune functional performance. Traditionally, dislocation engineering in ceramics was considered impractical due to their intrinsic brittleness. However, advances in processing and deformation techniques now allow for controlled introduction of dislocations without catastrophic cracking, opening new pathways for tailoring ceramic properties. Beyond mechanical properties, dislocations in ceramics are accompanied with high local strain gradient, electrostatic interactions, and local defect chemical environment that impact functional responses. Despite increasing experimental and computational evidence, a comprehensive synthesis of these effects remains lacking. This review highlights representative dislocation-tuned functional properties in ceramics, including transport, ferroelectric, thermal, superconducting, and optical behaviors, and provides insights into the emerging role of dislocation engineering in advancing functional ceramics for potential diverse applications.

Hydrovoltaic technology, especially the power generation driven by natural evaporation of water, has great potential for sustainable development, but its performance may degenerate significantly in seawater. Here, we find that sulfonated natural woods can generate power even more efficient by evaporation of seawater than deionized water. A single sulfonated maple device yields potential of 0.97 V with power density of 15.5 mu W cm-2 through evaporation of seawater, in comparing to the yield of 0.77 V and power of 6.2 mu W cm-2 through deionized water, one order higher than the best reported performance in saline-environment. Integration of four such units in series and parallel yields voltage of 2.3 V and current of 2.6 mA, respectively. It is revealed that sodium ion-wood interactions and the coupling between capillary-driven flow and ion transport are the root for the induced electricity. The power generation can maintain stable over 100 h when the wood sample is washed by fresh or rainwater periodically. It is also interesting that once wetted in seawater, the wood sample can produce power stably over 7 h in air. Since the ocean covers 70% of the earth's surface and absorbs a large amount of solar energy through evaporation, this discovery is particularly promising.

Evaporation-induced electricity generation offers a promising route to harvest energy from ubiquitous water, but most systems rely on complex nanomaterials or surface modification, limiting scalability. Here, we report a simple, modification-free strategy to construct a resin-based hydrovoltaic generator from natural pine. A one-step degreasing treatment removes aliphatic components that hinder water transport and activates intrinsic resin acid groups, achieving a 22-fold increase in power density over untreated wood. The degreased pine delivers 410 mV and 8 mu A from a 10 & times; 10 & times; 2 cm3 block, while six units produce up to 2.3 V and 50 mu A. The device shows stable output over 110 h and reliable operation in diverse aqueous environments, offering a low-cost and scalable approach for hydrovoltaic energy harvesting.

Tantalum (Ta) implants are often limited by the inherent strength–ductility trade-off and insufficient corrosion resistance in physio;ogical fluids, while conventional alloying often introduces high costs and potential biosafety risks. In this study, a gradient interstitial oxygen architecture was engineered in Ta via low-pressure oxygen diffusion to address these challenges. Interstitial oxygen dissolution contributed approximately 50% of the total weight gain, with diffusion coefficients following the Arrhenius relationship (D0 = 2.8 × 10-3 cm2/s, E = 23.6 kcal/mol). The optimized Ta700 sample exhibited an increase in tensile strength from 315 MPa to 380 MPa while retaining a substantial 18% elongation, a synergy enabled by the combination of solid-solution hardening and the back-stress enhancement induced by the interstitial oxygen gradient. Furthermore, the corrosion potential shifted from -0.36 V to -0.26 V (vs. SCE), and the charge transfer resistance increased from 1.36 to 17.8 MΩ·cm2, representing an approximately thirteenfold enhancement, primarily due to the formation of a denser passive film promoted by the interstitial oxygen. The superior fluidity and exceptional permeability of the gas phase (0.1%O2/Ar) ensure that interstitial oxygen can effectively penetrate the internal constituents of these complex architectures, providing a versatile post-processing strategy for the precise functional modification of 3D-printed biomedical components in the future.

Flexible aerogels combining mechanical adaptability and functional performance are crucial for next-generation wearable electronics. However, their practical deployment is constrained by the intrinsic strength-flexibility trade-off. Here, we propose an ion-mediated nanoengineering-based fabrication strategy to construct flexible wood-derived aerogels with outstanding mechanical robustness and ionic conductivity. Partial delignification preserves the wood's load-bearing hierarchical honeycomb framework while exposing cellulose chains for interactions with ionic liquids. This interaction reorganizes the hydrogen-bonding network among cellulose chains through extensible ionic bridges, thereby enhancing cell wall elasticity and imparting ionic conductivity. Benefiting from the preserved wood scaffold and ionic liquid-induced nanoscale reconstruction, the resulting aerogel withstands 90% compressive strain, 180° bending, and 720° twisting, while reaching a compressive strength of 1.75 MPa, far exceeding most flexible aerogels. Moreover, its ionic conductivity enables stable piezoresistive sensing of diverse human motion signals, showing great promise in flexible sensing and wearable electronics.

The simultaneous and instantaneous occurrence of ultra-short time species diffusion, thermal transportation and mechanical deformation in the thermal protection system and the high-power devices usually produces the complex responses of coupled multi-physical fields, which greatly impacts the service performance of the key materials and structures components. In this study, the second-order rate and characteristic time are introduced to include transient effects through Taylor expansion, the governing equations of a transient mechanics thermal diffusion (MTD) coupled model are established to discuss the coupling and transient effects on the responses of physical field such as the temperature, concentration, chemical potential and stress distribution along a bar. The derivation method of this paper follows the assumption of local equilibrium in non-equilibrium thermodynamics and establishes the linear flux-force relations that essentially ensures the positive definiteness of entropy production rate. In addition, it is found that the stress solution of the MT coupled problem can be expressed as that of decoupled counterparts subtract an empirical function. With this, the mechanism of sudden stress change at the elastic wavefront location in the MT coupled model can be well revealed. Furthermore, the relative locations of elastic, thermal and diffusion wavefronts may change since the wave velocity dependent on the characteristic time may vary as the material property evolves. The conclusions and findings of this study may provide a new way for the design, manufacturing and modeling analysis of high-temperature thermal protection materials and high-power devices.

CaF2 optical components are critical elements in DUV lithography systems, and their performance degradation directly impacts system reliability. The simultaneous thermal and photochemical effects of deep ultraviolet (DUV) nanosecond light source irradiation on optical elements' intricate component irradiation damage mechanisms, posing challenges for accelerated lifetime studies. Therefore, this study examines the combined accelerating impact of photothermal and photochemical effects on component damage by contrasting the damage evolution under different deep ultraviolet laser irradiation scenarios. The consistency observed between the absorption spectra and XRD characterization results indicates that photochemical effects dominate in the initial irradiation stage, manifested by the irradiation-induced generation of M centers and the development of tensile lattice strain. However, accelerated irradiation amplified the UV absorbance by about 104 compared to real-time irradiation. Contamination increased the RMS roughness by 10∼102 relative to non-accelerated samples, and the average UV absorbance rose by 19.93%. Therefore, the thermal effects of irradiation influence the photochemical processes and surface roughness of optical elements by promoting defect generation and aggregation, internal stress states, and contaminant reaction rates, respectively.

Determining the flexoelectric coefficient components is a fundamental challenge in the community of flexoelectric materials. In this work, the strain-gradient-induced polarization in macroscopic bent strontium titanate single crystals is utilized to elucidate the crystal orientation-dependent flexoelectric coefficient of this material. The effective flexoelectric coefficient along the cubic crystallographic axes can be used to derive theoretical expressions. A three-dimensional coordinate transformation is then applied to derive the flexoelectric coefficients for (001), (110), and (111) orientations in global coordinates. A relationship between the effective flexoelectric coefficients for these orientations is obtained, which is validated using a three-point bending test. Our work provides valuable theoretical and experimental insights into the evaluation of flexoelectric coefficients in dielectric materials, contributing to a deeper understanding of their crystal-orientation dependence.

Ionogels as ionic conductors have attracted extensive attention due to their excellent ionic conductivity, good thermal and electrochemical stability, and favorable non-volatility compared to conductive hydrogels. However, ionogels with excellent conductivity usually suffer from low strength and modulus. Herein, a facile yet effective strategy by compositing aligned cellulose fibers with ionogels is presented to achieve superior mechanical properties and high ionic conductivity. The triple hydrogen bond networks enable the ionic conductors to possess superhigh tensile strength (approximate to 32.75 MPa) and Young's modulus (approximate to 1354 MPa), as well as exhibit excellent crack-resistant properties. Meanwhile, the ionic conductors with aligned cellulose fibers provide oriented hierarchical micro- and nanochannels for accelerating ion transport and thus can obtain a high ionic conductivity. Moreover, the ionic conductors exhibit high optical transparency (approximate to 92%), good adhesion, and favorable flexibility. This work provides a straightforward and effective strategy for the development of high-strength, high-conductivity, and crack-resistant ionic conductors.

With the world's increasing focus on environmental protection and sustainable development, the development of sustainable smart materials has become one of the most important research topics in this field. In recent years, wood, with its distinctive hierarchical porous structure and natural characteristics, has emerged as an ideal candidate for constructing smart materials. Building on this foundation, this review explores the unique advantages of wood-based smart materials in terms of structural and chemical composition, beginning with an analysis of wood's structure and composition. At the molecular scale, the review discusses mechanical behavior mechanisms driven by molecular interactions within wood-based smart materials. Subsequently, it summarizes various microstructural adjustment strategies to enhance the macroscopic mechanical properties of wood-based smart materials at the cellular level. Furthermore, the review analyzes research progress in wood-based smart materials with sensing, environmental responsiveness, shape memory, and self-healing properties. Finally, it concludes by summarizing current challenges in processing techniques and applications of wood-based smart materials, while offering insights into future research directions for this promising field.

The protective function of the oxide scale and the vulnerability of the subsurface region play key roles in determining the high-temperature durability of AlCoCrFeNi high-entropy alloys (HEAs), yet their degradation mechanisms remain insufficiently understood. This study investigates the mechanisms of oxide scale spallation and subsurface mechanical degradation in the AlCoCrFeNi HEA after high-temperature oxidation at 1000 degrees C. Severe oxide scale spallation is not solely caused by residual stress but is closely linked to vacancy coalescence at the oxide/alloy interface, primarily induced by outward Al diffusion and the Kirkendall effect. A bilayer Al2O3 scale (approximate to 8.4 mu m thick after 200 h oxidation) forms, consisting of equiaxed and columnar grains. Moreover, the subsurface region undergoes a body-centered cubic (BCC)-to- face-centered cubic (FCC) phase transformation, which reduces the diffusion coefficient of Al (from 4.17 x 10-11 m2 s-11 in BCC to 1.8 x 10-11 m2 s-1 in FCC), thereby enhancing oxidation resistance. Meanwhile, nanomechanical testing reveals an approximate to 30% reduction in yield strength in the subsurface layer, attributed to vacancy-induced reductions in stacking fault energy, which promote dislocation activity and plastic deformation. This study provides critical insights into the coupled effects of oxidation, vacancy dynamics, and phase transformation on the high-temperature performance of HEAs, offering valuable guidance for their application in extreme environments.