Dielectric phase-change metasurfaces enable programmable light control and show great application potential in optoelectronics. However, current technologies are limited by challenges in achieving high-uniformity, high-precision fabrication over large areas, as well as selective phase-state modulation of individual meta-atoms. To address these challenges, a femtosecond (fs)-laser phase-modulated non-diffracting-beam lithography (PNDL) technique is proposed. By superimposing axicon and blazed grating phases, the fs-laser beam is shaped into a quasi-Bessel non-diffracting-beam with a depth of focus over 10 times greater than that of a tightly focused Gaussian beam, thereby reducing the need for refocusing and minimizing focal drift. The dynamic beam deflection during fabrication can be controlled with 7 nm precision. The voxel metasurfaces composed of phase-change regions are then chemically processed to achieve maskless lithography. PNDL is used to fabricate a tunable Ge2Sb2Te5 metasurface with a structural feature size of 9 nm. Furthermore, multifunctional programmable photonic logic devices are fabricated and modulated, demonstrating high-precision capabilities. This approach provides a novel paradigm for active metasurface fabrication and modulation, laying the foundation for next-generation photonic devices.

Hydrogel materials are excellent biocompatible materials with numerous applications in biomedical devices. However, their low viscosity and high fluidity pose significant challenges to achieving high fidelity in biofunctional structures during additive manufacturing. In this paper, we present a femtosecond laser processing system based on simultaneous spatial and temporal focusing (SSTF), which employs coordinated regulation of temporal pulse stretching via blazed gratings and spatial energy gradients to generate a super-Gaussian optical field at the focal plane. Through optical simulations and experimental validation, the physical mechanism by which the super-Gaussian energy distribution of the SSTF optical field suppresses material flow and enables uniform curing is revealed. Experimental results demonstrate that, compared to traditional Gaussian laser processing, the SSTF technology significantly enhances surface smoothness (Ra < 0.5 mu m) and interlayer bonding quality (interlayer thickness variation +/- 0.5 mu m), successfully fabricating various biofunctionalized structures. In vitro validation experiments demonstrate that the functional structures printed exhibit surfaces capable of supporting cells, maintaining high viability, and forming complete cytoskeletal networks, while significantly promoting cell proliferation and osteogenic differentiation. This three-dimensional controllable polymerization process, which relies on radial energy gradients to inhibit material flow and axial localization control, provides a high-fidelity, biosafe manufacturing strategy for medical applications.

Femtosecond laser machining of specialty alloys has evolved into a high-precision, low-damage technology with extensive applications in micro- and nano-scale fabrication. However, the lack of atomic-scale underlying mechanisms significantly hinders the efficiency of process optimization. This study investigated the electron dynamics and ultrafast phase transitions of nickel-based superalloys at the atomic level using pump-probe microscopy and molecular dynamics coupled with the two-temperature model (MD-TTM). Within the first 2 ps, electron excitation and scattering increased the transient differential reflectivity (TR). Beyond this timescale, the onset of mechanical relaxation and phase transitions in lattice system decreased the TR. Spatiotemporal analysis of TR micrographs identified thresholds for spallation and phase explosion and confirmed the coexistence of these two-phase transition mechanisms. The experimental observations were further demonstrated by atomicscale insights from MD-TTM simulations, which capture the evolution of electron-lattice energy transfer, lattice density variations and, material ejection dynamics. Based on the identified mechanisms, the morphology of both the ejected materials and the processed surface can be tuned by precisely adjusting the laser fluence. This study offers fundamental insights into the complex ultrafast processes governing femtosecond laser-alloy interactions and establishes a theoretical foundation for material ejection and surface morphology regulation, enabling high-precision micro/nanostructure fabrication.

The excellent electrocatalytic activity of metal-organic frameworks (MOFs) has shown great potential in applications, but has also posed outstanding challenges due to their poor conductivity and electrochemical stability. Here, we report a novel and promising self-supported oxygen electrocatalyst featuring bimetallic MOF nanosheets loaded on femtosecond-laser-constructed CoCrFeNi high-entropy alloy substrate (CCM/FHEA). This integrated design leverages synergistic advantages-including expansive specific surface area, rapid electrolyte exchange, and strong electronic interaction-to achieve exceptional oxygen evolution reaction (OER) activity and stability, with a small overpotentials of 231 mV to reach the current density of 10 mA & centerdot;cm-2 and a Tafel slope of 53.3 mV & centerdot;dec-1. Furthermore, this electrocatalytic system recorded excellent reaction stability over 300 h with a constant current density of 150 mA & centerdot;cm-2 at the potential of 1.56 V vs. RHE. Finite-element simulations demonstrate the intensified potential gradients and electric field intensity on the CCM/FHEA electrode surface, while density-functional theory calculations uncover the regulated electronic structure and reduced reaction energy barrier in post-formed CoCubased oxyhydroxide analogue during OER. This work provides a feasible strategy for the rational design and construction of MOFs-based hierarchical self-supported electrocatalysts for efficient energy conversion technologies.

Nontrivial band structure topology can be induced through time-periodic fields via Floquet engineering. Here, using time-dependent density functional theory, we demonstrate that above-bandgap circularly polarized photoexcitations induce the formation and splitting of exceptional point (EP)-like degeneracies in the strongly correlated material NiO. The polarization-selective splitting sequence of upper (UEP-like) and lower (LEP-like) EP-like degeneracies reveals laser-driven phase transitions. Spin fluctuations under polarization switching confirm the annihilation of the z-spin component and emergence of tunable x–y plane spin component, indicating that ultrafast demagnetization generates in-plane spin reorientation. Concurrently, the time-dependent reduction in the orbital-effective Hubbard U and many-body energy evolution demonstrate a transition of electrons from localized to itinerant states. This work establishes the strongly correlated insulator NiO as a distinctive platform for light–matter coupling. Crucially, we demonstrate that resonant above-gap excitation is an essential prerequisite for dynamical control, which not only reveals photon energy as a decisive parameter for steering non-Hermitian phenomena but also enables the controlled transition from an insulating state to metallicity.

High-strength femtosecond laser welding of metals to ceramics remains a critical challenge for the practical application of dissimilar joints in aerospace, marine, and medical devices. In this work, Ti films with different thicknesses are proposed to enhance the bonding strength of sapphire/Invar36 joints, and the ultrafast laser-induced dynamics on Ti-coated Invar36 surfaces are further investigated. The results show that Ti films markedly enhance mechanical interlocking at the sapphire/Invar36 interface, significantly increasing both shear and tensile strengths. Under the same laser fluence, the Ti-coated surface exhibited a larger focal region and a faster decrease in reflectivity, whereas the bare surface showed a slower decrease in reflectivity and pronounced Newton's rings within the focal region. In addition, greater melt depth and increased plasma intensity and lifetime were observed on Ti-coated surfaces, suggesting that Ti films promote interfacial melting and bonding. However, increasing the Ti thickness also caused more severe cracking in the sapphire. An optimal Ti thickness of 150 nm yielded peak joint strengths of 212.96 MPa (shear) and 64.40 MPa (tensile). These optimized joints retained relatively high strength after thermal aging and thermal cycling, indicating improved thermal stability compared with joints without an interlayer.

Metal corrosion poses a significant challenge in industrial applications. Slippery liquid-infused porous surfaces (SLIPS) have garnered considerable attention for corrosion protection due to their low adhesion and liquid-repellent characteristics. In this work, we constructed SLIPS on aluminum (Al) substrates by fabricating hierarchical porous micro/nanostructures via temporally shaped femtosecond laser, followed by fluorination and lubricant infusion. The surface wettability, mechanical durability, and corrosion resistance of the fabricated surfaces were systematically investigated. Two-temperature model (TTM) simulations indicate that double-pulse irradiation suppresses the peak electron temperature by 16.92% and leads to more uniform energy deposition. The SLIPS exhibits effective self-cleaning behavior, stable slippery performance under acidic and alkaline environments, and enhanced mechanical durability. Electrochemical impedance spectroscopy (EIS) measurements show that the low-frequency impedance modulus |Z| of the SLIPS reaches 2.06 x 106 S2 center dot cm2 initially and remains 1.07 x 105 S2 center dot cm2 after 28 days of NaCl immersion. As a result, the laser-induced SLIPS significantly improves corrosion resistance relative to bare Al surface and maintains its protective capability after mechanical damage through spontaneous self-healing. Overall, this work presents a facile and effective laser-based strategy for constructing self-healing and corrosion-resistant SLIPS on Al substrates, offering promising potential for corrosion protection in harsh environments.

The exploration of the interaction process between femtosecond lasers and metals through experimental and theoretical methods has become a major research focus. However, the comprehensive analysis of the transient thermal and optical information inside the ablated metal induced by a femtosecond laser is a challenging task. Ultrafast dynamics processes for an Invar alloy under femtosecond laser irradiation are reported in this work. Ablation mechanisms including ultrafast melting, expansion, spallation, and transition mode between spallation and phase explosion for Invar alloy are analyzed through experiments and simulations. Adopting the theoretical framework of molecular dynamics coupled with a two-temperature model (MD-TTM) and multilayer film optics, the relative reflectivity images reconstructed are in good agreement with pump-probe experiments. 3D transient complex refractive index tomography of Invar alloy after femtosecond laser excitation has been obtained. By coordinating the experiments with theories, the electro-thermodynamic pathways constructed on a four-state diagram (reflectivity, temperature, pressure, and density) for transient ablation of Invar alloy offer a means of quantifying the photothermal information. The methods employed precisely bridge experiments with theories, which may contribute to investigating ultrafast ablation in different material systems, meeting photothermal data requirements for high-temperature states, and precisely controlling material eruption and redeposition by adjustable subpulse intervals and repetition rates.

Bone defects caused by trauma or severe diseases present significant clinical challenges. In this study, a multifunctional, multiscale therapeutic platform based on NiTi alloy was developed, exhibiting enhanced osteointegration and antibacterial performance. Femtosecond laser direct writing was first used to create micro-grooves with periodic ripple structures, promoting osteointegration via contact guidance effects. Subsequent anodizing generated a nanostructured porous layer on this microstructure, further enhancing biocompatibility and osteointegration. Finally, a polydopamine coating was applied to facilitate the in-situ incorporation of nanosilver, imparting strong antibacterial properties while simultaneously enhancing cell adhesion. MC3T3-E1 cell adhesion and differentiation assays confirmed the platform's robust osteogenic capacity. Additionally, the system achieved bactericidal efficiencies of 99.86 % against E. coli and 99.69 % against S. aureus. Overall, this study presents a comprehensive and effective method with high potential for bone defect repair.

Planar microsupercapacitors (P-MSCs) with high power density and conformal configurations could provide on-chip power supply in the design of highly integrated electronics. However, achieving a breakthrough in overall energy within a finite footprint requires establishing an effective structure-performance relationship. Here, we present a cascaded spatial confinement strategy to construct a 3D interlocked P-MSC that couples force fields with charge transport/storage behavior, enabling ion-electron enrichment. Laser-etched pyramid microarrays on graphite current collectors create capillary forces that confine both electrode slurry and electrolyte to build a compact conduction network, while establishing a robust ion-electron interaction interface, significantly facilitating ion accessibility and kinetics. Using Zn//active carbon (AC) P-MSC as an example, the strategy boosts active material utilization by over 2-fold, and delivers an outstanding energy density of 117.5 mWh cm-3 and a power density of 2382.0 mW cm-3, exceeding those reported for Zn//AC P-MSCs by several to tens of times, and surpassing nearly all existing Zn-based P-MSCs in areal performance. The approach demonstrates reliable universality across various P-MSC systems (eight types are verified). Integrated devices show notable advantages in powering miniaturized electronics and flexible displays, possessing a voltage output approximately 4.7 times that of a same-sized dry battery, and are also configured as emergency power chips to charge smartphones.

The sluggish kinetics of the alkaline hydrogen evolution reaction (HER) stemming from *OH poisoning on Pt-based catalysts pose a barrier to efficient anion exchange membrane water electrolyzers (AEMWEs). To address this, we developed a non-equilibrium femtosecond laser ablation in liquid (fs-LAL) method to synthesize defect-rich PtRe alloy clusters (similar to 1.88 nm). This method overcomes thermodynamic immiscibility between Pt and Re, enabling metastable alloys with rich structural defects and lattice distortions, unattainable by conventional methods. The optimized Pt15Re/C catalyst delivers superior alkaline HER performance in 1 M KOH, with an overpotential of 12.6 mV at 10 mA cm(-2), surpassing commercial Pt/C (23.9 mV). In an AEMWE, the catalyst achieves an industrial current density of 1.0 A cm(-2) at 1.68 V (60 degrees C) with stability over 350 h, surpassing most reported counterparts. Density functional theory (DFT) calculations, using a PtRe cluster, reveal a synergistic dual-site mechanism: oxophilic Re atoms facilitate H2O activation and *OH adsorption, alleviating poisoning on adjacent Pt sites, which maintain near-optimal hydrogen adsorption free energy (Delta G(H*)) for efficient H* desorption. This work demonstrates the efficacy of non-equilibrium synthesis for creating metastable bimetallic clusters, providing a versatile strategy for advanced electrocatalysts in green hydrogen production.

NiTi alloy serves as an important biomedical material, and its functional surface processed by femtosecond laser has clinical application prospects. The knowledge of transient properties and phase change is the footstone of the quantitative prediction of femtosecond laser processing of NiTi alloy, but is not adequately studied. This work aims to address the data accessibility of electron temperature-dependent properties of NiTi alloy and the investigation of femtosecond laser-induced phase change based on these data. The electron heat capacity and electron-phonon coupling factor of NiTi alloy are obtained by the density functional theory and density functional perturbation theory with ab initio accuracy, which makes the multiscale simulation feasible. The atomistic motion during phase change is captured by snapshots in the molecular dynamics coupled two-temperature model (MD-TTM). To overcome the effect of the Langevin thermostat on pressure wave propagation, a temporally partial-applied MD-TTM method is proposed, which predicts a reversible solid-solid phase change within tens of picoseconds under the melting region. The optical response of ejected atoms in phase change is experimentally observed by transient reflectivity microscopy. It is found that the experimental reflectivity drop and simulated atom ejection have the same time range. The agreement between experimental and simulated ablation thresholds proves the validation of the proposed temporally partial-applied MD-TTM method. The simulated atomistic structure change after femtosecond laser processing is supported by the experimental characterization of the surface amorphous and subsurface crystal structures. The reported data and results contribute to further quantitative investigation and application of NiTi alloy processed by femtosecond laser. (c) 2025 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

Ultrafast continuous imaging techniques face inherent trade-offs among sequence depth, temporal resolution, and system complexity. To address this, we developed Supercontinuum Photon Encoded Extreme Dynamic Snapshot Imaging (SPEED-SI). This technique employs precise spectral segmentation at the Fourier plane, discretizing a supercontinuum pulse into multiple independent spectral channels. Our system enables single-shot ultrafast imaging at 36 frames per acquisition with femtosecond exposure time and a peak frame rate of 10.5 trillion frames per second (Tfps). By implementing a higher-density diffraction grating, we further expanded the sequence depth to 45 frames and achieved an enhanced peak frame rate of 17.9 Tfps, which represents the highest sequence depth reported for direct continuous imaging on the femtosecond timescale. The system outputs high-fidelity images in real time without computational reconstruction or associated artifacts. Moreover, ultraviolet-continuum generation from a calcium fluoride crystal demonstrates the potential for further expansion of the spectral bandwidth and sequence depth, establishing SPEED-SI as a powerful tool for investigating ultrafast phenomena.

Artificial synapse (AS) offers a promising approach to emulate biomimetic nervous systems and potentially overcomes the von Neumann bottleneck. Despite their potential, current neuromorphic devices still suffer from challenges, including electrolysis risks, material degradation, ferroelectric fatigue, and irreversible conductance changes from ion migration and trapping. Here, we propose a self-trapping mechanism due to the intrinsic structural distortion of FePSe3 induced by strong electron-phonon (e-ph) coupling, which preferentially captures electrons, forming polarons within 1 picosecond (ps) and extending carrier lifetimes to tens of nanoseconds (ns). A memristor based on polarons formed in FePSe3 via the nondestructive capture and release of electrons transferred from graphene (Gr) was realized, exhibiting a large memory window exceeding 124 V and stable electrical performance over more than 103 switching cycles. Furthermore, FePSe3-Gr devices show good synaptic plasticity stimulated by different amplitudes and numbers of electrical pulses, indicating the capacity to be applied in AS devices. Meanwhile, the synaptic reset function is observed due to the saturation formation of polarons under optical injection. Our findings present a microscopic approach for stable, high-performance AS devices, advancing their application potential in neuromorphic systems.

Thrombosis and bacterial infections pose critical challenges for blood-contacting implants, inducing serious morbidity and mortality. Inspired by the vascular endothelium, we present an eco-friendly and facile strategy to construct a structurally enhanced, integrated offensive-defensive coating with exceptional hemocompatibility, biocompatibility, and antibacterial activity. Hierarchical cobblestone-like micro/nanostructures are fabricated on the pyrolytic carbon via femtosecond laser ablation. Subsequently, copper ions (offensive component) are immobilized onto the structured surface through dopamine-mediated adhesion, enabling the catalytic generation of endogenous nitric oxide to actively interrupt the thrombosis cascade and bactericidal action by disrupting their membranes. Following this, a zwitterionic polymer is grafted onto the surface to form a hydration layer (defensive component), which passively inhibits the adhesion of biofoulants. The pre-engineered hierarchical structures effectively enhance copper ion loading capacity, stabilize the interfacial hydration layer, and simultaneously reduce the availability of anchoring sites for biofoulants. The resulting biomimetic coating exhibits excellent biocompatibility, with an ultralow hemolysis rate (0.1%, below ISO 10993-4 standards) and nearly 100% endothelial cell viability after 48 h of coincubation. It also demonstrates robust defensive performance, markedly reducing the adhesion of platelets (by 99.6%), fibrin (by 69.8%), and bacteria (by 99.1% for S. aureus and 95.5% for E. coli) compared to the pristine surface. Additionally, the coating achieves outstanding offensive functionality, with negligible platelet activation and high bactericidal efficiencies of 92.8% and 77.1% against S. aureus and E. coli, respectively. This endothelium-mimicking, drug-free strategy provides a versatile platform for durable, biocompatible cardiovascular implants, potentially reducing clinical complications and improving patient outcomes.

Femtosecond laser-driven synthesis provides a versatile method for producing nanoparticles with high purity and compositional tunability, suitable for applications in catalysis and nanomanufacturing. However, conventional kinetic models typically treat reactions as continuous, overlooking the pulsed nature of laser excitation, thereby constraining their applicability in directing experimental synthesis. In this study, we established a femtosecond laser-induced strategy for nanostructures by dividing the processing timeline into pulse-on and pulse-off phases to elucidate nanoparticle formation dynamics. Nanoparticle generation encompasses two principal processes: Ultrafast reduction and nucleation (k(1)) primarily during pulse-on phases, and growth (k(2)) across both phases. Mass spectrometry further revealed the evolution of solution species in a representative metal precursor system. Employing this framework, we adjusted laser repetition rate to modulate pulse-on proportion. Higher repetition rates increased k(1), boosting nucleation and yielding smaller nanoparticles. Lower rates favored k(2), producing larger particles. This methodology was extended to synthesize diverse monometallic, bimetallic, and high-entropy nanoparticles across various elements and substrates, as demonstrated by their applicability in representative electrocatalytic reactions, including CO2 reduction and hydrogen evolution. This work offers a mechanistic basis connecting laser parameters, pulsed dynamics, and nanoparticle properties, promoting rational ultrafast laser nanomaterial design for a wide range of metal and alloy systems.

The global scarcity of water resources poses substantial challenges to human society, prompting the need for innovative solutions. Recently developed solar-driven interfacial evaporation (SDIE) has emerged as an effective approach to harvest clean water with low cost and eco-friendliness. Laser processing technology, characterized by its simplicity, efficiency, and sustainability, has attracted significant interest within the domain of SDIE. In this review, the conversion of solar energy into thermal energy and the mechanisms of water transport for SDIE are first introduced. Then, laser etching, laser-induced graphitization (LIG), laser in-situ synthesis of LIG/composites, liquid-phase pulsed evaporation, and so on, laser processing techniques for modifying material properties to enhance water evaporation performance are discussed, as well as the advantages and limitations. Finally, the review offers a forward-looking perspective on potential future advancements, which would provide the insight into the domain of laser processing technologies for SDIE.