Lithium metal anodes hold great promise for high-energy-density batteries but are hindered by issues such as dendritic growth, interfacial instability, and electrode degradation. To mitigate these challenges, we propose a laser-engineered dual-structured electrode design that optimizes both electrodes. The anode, a hierarchically micro-pillared copper (LHM-Cu), redistributes Li+ flux, reducing the normal-to-total current density ratio from 0.90 to 0.58 and thereby enabling uniform deposition. Li||LHM-Cu half-cells achieve an average Coulombic efficiency of similar to 96% over 450 cycles, and symmetric cells exhibit extended stability of similar to 700 h. The cathode, a groove-patterned aluminum (LSG-Al), shortens ion diffusion pathways and improves interfacial transport and adhesion. Full cells at 1 C demonstrate the combined benefits of dual structuring: initial discharge capacities reach similar to 140 mAh g(-1), compared with similar to 108 mAh g(-1) for anode-structured-only and similar to 78 mAh g(-1) for cathode-structured-only cells. After 100 cycles, the dual-structured cell retains similar to 99% of its initial capacity, outperforming the anode-only cell (similar to 91%) and highlighting the complementary contributions of cathode structuring to capacity stabilization. Complementary picosecond and femtosecond laser processing enables structural precision without compromising mechanical integrity. This design mitigates degradation arising from electrode interactions, offering a generalizable pathway toward safe, durable, high-energy lithium metal batteries, with potential applicability to other metal-based energy storage systems.

Diamond is an exceptional wide-bandgap semiconductor for electronics and quantum technologies. While femtosecond laser processing enables micro/nano fabrication of diamond, the dynamic atomic-level structural evolution during this process remains poorly understood, despite its critical impact on advanced applications. In this work, we investigate the multi-stage structural evolution of diamond under femtosecond laser irradiation, uncovering new scientific findings under laser-induced extreme conditions. The continuous input of pulse energy facilitates the rearrangement of local carbon atoms in the modified layer and partial phase transition layer, transitioning them from thermodynamically unstable to stable states. We introduce a sequential evolution pathway of nanocomposite carbon structures, and reinterpret the phenomenon previously broadly defined as “graphitization”. Specifically, the evolution of diaphite, diamond-OLC (onion-like carbon), and the transition from amorphous carbon to planar-oriented graphite are reported under femtosecond laser surface processing. These phase transitions are initiated by the rapid lattice heating, with their distribution influenced by near-field enhancement effects arisen from surface nanostructures. This work provides atomic-scale insights into diamond's response in femtosecond laser processing, offering a theoretical foundation for ultra-precision micro/nano fabrication of diamond and the development of functional carbon materials.

Microgrooves with diverse cross-sections are required in various fields but remain a significant challenge in precision machining, especially for hard-to-machine materials. Patterned laser ablation offers an avenue for fabricating microgrooves on any material with notably enhanced shape diversity. However, it is hard to precisely control the grooves’ cross-sectional profiles due to the complex ablation process, including the diffraction-induced energy distribution variations away from the focal plane and the inconsistent polarization-related energy absorption. These factors complicate the relationship between beam spot shape and ablated groove shape, making it challenging to design appropriate spot shapes for specific groove requirements. Here, we propose an adaptive beam-shaping method for laser spot design to improve microgrooves’ shape accuracy. Combining laser diffraction and polarization effects, a profile evolution model of the laser ablation is established to accurately predict groove shapes, guiding the iterative beam-shaping procedure. The beam spot shape is iteratively fine-tuned until the deviation between the simulated and the target grooves’ profile meets the accuracy requirements. The grooves’ profile deviations are significantly reduced, with the final profile’s root mean square error decreased to less than 0.5 μm when processing microgrooves with a width of 10 μm. Various microgrooves with precise cross-sections, including triangles, trapezoids, and functionally contoured microstructures, are achieved by patterned laser direct writing assisted with the adaptive beam-shaping method. This method paves the way for laser ablation of microgrooves with high shape accuracy for traditional hard-to-machine materials.

Precision machining of micro-structured glass components is crucial for numerous applications, yet conventional machining methods face challenges in achieving customizable high-quality microstructures on glass. Here, we propose a new concept of laser-enhanced etching, termed laser-guided vectorial etching (LGVE). In LGVE, material removal rates and directions are guided akin to a vector characterized by both magnitude and direction along laser-modified tracks, differing from the conventional isotropic wet etching of glass. Laser modifications accelerate the material removal of chemical etching, while the track guides the removal direction, allowing flexible control over the overall etching evolution of surface morphology and fabricating glass microstructures with sharp features, diverse shapes, and adjustable sizes. Through spatially stitched multi-scanning and locally adjustable laser energy deposition, a variety of modified tracks are created inside glass bulk, including segmentally gradient modified-line, tilted-line ranging from 0 degrees to 60 degrees, and arc-shaped tracks with radii of 35 50 mu m. Successful fabrication of microgrooves with bell-like, slant, and curve-shaped cross-sections of customizable sizes showcases the versatility of LGVE. Finite difference simulations validate the efficacy of LGVE, enabling the design and optimization of etched micro-grooves for higher structural resolution ( 1 mu m) and the production of low-angle ( 10 degrees) blazed gratings. These advancements propelled by LGVE can potentially revolutionize machining methods for glass microstructures.

The development of extreme impact-resistant materials holds significant importance across engineering applications, yet remains constrained by the inherent trade-offs among mechanical strength, toughness, and energy dissipation efficiency. Drawing inspiration from natural models, particularly the unique structural design and toughening mechanisms of the mantis shrimp's dactyl club, a kind of nanocomposite hydrogel is developed by synergistically integrating polymer elastic microspheres with enzyme-induced biomineralization. This bioinspired approach produces microsphere-reinforced nanocomposite hydrogels (MNHs) that concurrently deliver exceptional strength, remarkable fracture toughness, and unprecedented resistance to ballistic impacts, surpassing the performance of all existing high-strength hydrogels, thus underscoring their potential for protective applications. Nonlinear numerical and theoretical analyses elucidate the dynamic fracture mechanisms governing both quasi-static and high-speed impact scenarios, revealing crack deflection, microcrack nucleation, and energy redistribution as key toughening pathways. This work not only advances the fundamental understanding of bioinspired structural design principles but also establishes a universal blueprint for next-generation impact-resistant materials, unlocking new frontiers for polymer composites in mechanically demanding scenarios.

Micro-engineered glass components play a vital role in various domains, but their full potential remains untapped due to the lack of easily accessible high-precision machining methods for customizable microstructure. Our discovery of a new phenomenon, where laser-modified regions break the rule of inherently isotropic glass etching and regulate a directional anisotropic etching along modified tracks, has led to the development of a laser-guided anisotropic etching (LGAE) method. This method enables crafting precision glass microstructures with sharp features, smooth surfaces, and adjustable shapes and sizes. An ultrafast Bessel beam is utilized to create high aspect-ratio line-shaped modification within the glass. With a higher etching rate than pristine glass, the modified line guides directional anisotropic etching along the modified track, facilitating the formation of a V-shape with an angle altered by the etching ratio. These modified lines can further serve as basic building blocks to interconnect to construct a 3D internal modification region and then guide the glass's overall surface morphology etching evolution, enabling the creation of microstructures featuring designable shapes and adjustable feature sizes. To accurately predict and control the shape of the microstructures, we establish a finite difference etching model that incorporates localized etching rate regulation, validating the robustness and controllability of LGAE. This scalable method has successfully fabricated a 50 mu m period micro-pyramid array with high uniformity over a centimeter-scale area, demonstrating its suitability for large-scale manufacturing. The showcased micro-engineered glass components encompass V-groove arrays for fiber alignment, blazed gratings for light modulation, and microchannels with customized trajectories for microfluidic chips. These advancements driven by LGAE can significantly contribute to the progress of glass-based research and industries.

Laser-induced microjet-assisted ablation (LIMJAA) has been proven to be effective in fabricating high-quality surface structures. This achievement is attributed to the spontaneous generation of a continuous and stable microjet in liquid film, which prevents the recasting of ablation debris and eliminates the light-scattering effect of laser-induced cavitation bubbles. However, our experiments show that recasting occurs within the fabricated structures when laser repetition frequency exceeds a critical value in the LIMJAA process. Theoretical calculations and analyses confirm that the formation of a stable microjet requires a minimum pulse interval time exceeding the sum of the laser-induced cavitation bubble's lifetime and the microjet outflow time. This constraint of pulse interval time limits the maximum repetition frequency that LIMJAA can utilize, thereby affecting the method's overall processing efficiency. We found that reducing the liquid thickness and increasing liquid flowing velocity results in a shorter cavitation bubble lifetime and a quicker microjet outflow time, respectively, enabling shorter applicable pulse intervals. This significantly raises the usable maximum pulse repetition frequencies from approximately 40 kHz to 100 kHz. This study enhances our understanding of material removal mechanisms in LIMJAA technology and provides valuable theoretical insights for optimizing liquid-assisted laser micromachining performance. It paves the way for advancements in high-precision and efficient laser manufacturing.

Hierarchical micro/nanostructures have garnered considerable attention for their capabilities in light modulation, but the flexible fabrication of designed optical functional structures at both micro and nano scales remains challenging. Here, a polarization-modulated patterned laser ablation method complemented by flowing liquid is proposed to fabricate hierarchical microgrooves featuring tunable cross-sections and engraved surface nanostructures with controllable periods and orientations. The liquid-assisted ablation counters the shielding effect of ablation debris through laser-induced microjets, ensuring accurate control of the microgroove's shape by modulating the laser pattern in the focal plane. Simultaneously, the absence of debris also permits the consistent formation of laser-induced periodic surface structures (LIPSS) across the microgrooves. The LIPSS's period and orientation can be finely adjusted by manipulating the pulse energy and polarization within the patterned laser spot, facilitating the adaptable creation of hierarchical micro/nanostructures for optical application needs. As a demonstration, blazed gratings featuring orientation-customized LIPSS are fabricated, which exhibit polarization-dependent diffraction efficiency. The laser fabrication technique offers a highly versatile solution for sculpturing shape-controllable hierarchical gratings on hard-to-machine materials, paving the way for the swift production of customized optical elements. This work introduces a polarization-modulated patterned laser ablation method, complemented by flowing liquid, to fabricate hierarchical microgrooves featuring tunable cross-sections and engraved surface nanostructures with controllable periods and orientations. The laser fabrication technique offers a highly versatile solution for sculpturing shape-controllable hierarchical gratings on hard-to-machine materials, paving the way for the swift production of customized optical elements. image

Fabricating precision microgrooves with controllable cross-sections on difficult-to-machine materials is significantly valuable but still challenging. Herein, a patterned laser-induced microjet-assisted ablation method for cross-sectional profiles controllable laser micromachining is proposed. During the liquid-assisted laser ablation process, debris and bubbles that may disturb the laser energy deposition can be instantaneously expelled by a directional laser-induced microjet. The Gaussian laser spot is spatially modulated into specific geometric shapes, such as triangles, to tune locally deposited laser energy to carve microgrooves with designed cross-sections. To achieve customized microgrooves efficiently, a reliable geometrical model based on the ablation threshold theory is developed to guide the processing parameter selection, including the laser spot shape, polarization, pulse energy, and scanning strategies. The simulation and experimental results confirm that this method achieves the decoupled control of the groove depth and width in a single-path laser ablation process. Using this method, the design and manufacturing of microgrooves with controllable cross-sections on single crystalline silicon carbide are demonstrated. The patterned laser-induced microjet-assisted ablation method provides a new route for fabricating precision microgrooves with controllable cross-sections on difficult-to-machine materials.

Subwavelength‐structured metasurfaces working in visible and near‐infrared bands present a high challenge in large‐scale device fabrication. In this study, a scalable, high‐efficient, and low‐cost laser‐induced nanopatterning technique is exploited to fabricate a kind of short‐range disordered metagratings, which enables broadband polarization‐independent absorption in the visible to near‐infrared wavelength. The short‐range disorder of the laser‐induced nanogratings originates from the laser‐induced thermal effect and can be spontaneously organized during laser nanopatterning. The unique disorder can break the unidirectional characteristics of the nanogratings, which empowers the metagratings to excite coupled resonance modes. This helps to achieve near‐perfect absorption in the visible to near‐infrared band (400–1100 nm) with an excellent angular tolerance (up to 60°) and average absorptivities of 96.3% and 93.5% under the TM and TE modes, respectively. These low‐cost metagratings can potentially inspire wide applications in the fields of solar cells, sensing, and thermal emitters.

Laser-Induced Periodic Surface Structures (LIPSS) have been extensively studied as grating structures that form beyond the diffraction limit under laser irradiation over a large area. However,most LIPSS are essentially one-dimensional(1D)gratings,and this limited range of structural types in LIPSS hampers their widespread applications. To overcome this challenge,our study proposes a novel maskless two-dimensional (2D) laser nanopatterning method that combines the utilization of laser- induced thermal deformation effects and laser- Surface-Plasmon- Polaritons(SPPs) interference. By harnessing these two effects simultaneously,we can create two distinct periodic structures,namely wrinkles and LIPSS,in orthogonal directions. This innovative approach enables the generation of 2D wrinkled LIPSS on thin-film materials through a single-step laser irradiation process. Moreover,we have made significant advancements in the spatial modulation of the irradiated femtosecond laser,achieving a line shape with a length of 8 mm and a width of 7.78 mu m. This spatial modulation facilitates efficient nanopatterning of these 2D LIPSS on a millimeter scale within seconds. These breakthroughs greatly expand the range of achievable structural types with LIPSS,making them more suitable for mass micro/ nano fabrication. Our investigation focuses on the formation of wrinkles and LIPSS on Ge2Sb2Te5 (GST) thin-film materials,with an emphasis on laser-induced thermal accumulation, thermal deformation, and laser-SPPs interference. During the laser- induced thermal deformation, wrinkles spontaneously generate with a period of approximately 270 nm on a 50-nm-thick GST film over a silicon substrate. Importantly,these wrinkles maintain their stability in terms of their periods under laser irradiation with varying laser pulse energies. Furthermore, their periods can also be accurately controlled and predicted through a thermal deformation model,which has been validated on GST thin films with different thicknesses and substrate materials. Similarly,another periodic structure,namely LIPSS,can also spontaneously form due to the periodic ablation caused by laser- SPPs interference. The periods of LIPSS,measuring around 410 nm on the same 50- nm- thick GST film, can be modulated by adjusting parameters such as laser wavelength or incident angle. This independent modulation capability allows precise control over the periods of 2D wrinkled LIPSS in both orthogonal directions. Furthermore,we explore the morphological evolution of 2D wrinkled LIPSS and observe a gradual transition from excessive ablation and periodic structure generation to simple crystallization modification as the scanning speed increases or the laser pulse energy decreases. By manipulating the excitation intensity of laser- induced thermal effects and laser-SPPs interference through increasing the laser pulse energy under a fixed scanning speed, we can freely transform the generated periodic structures from wrinkled structures and 2D wrinkled LIPSS to 1D LIPSS. It is worth noting that the height of LIPSS can exceed 65 nm,while the corresponding wrinkle heights typically reach around 34 nm. Additionally,the orientation of 2D wrinkled LIPSS can be controlled by adjusting the polarization angle of the incident laser,adding another parameter to manipulate these structures. Moreover,we have discovered that 2D wrinkled LIPSS formed under different laser polarizations exhibit varying levels of uniformity. Comparatively,LIPSS display superior uniformity when compared to wrinkles,with their orientation being influenced by the polarization angle of the irradiated laser. The laser nanopatterning method proposed in this study demonstrates the immense potential for enhancing the diversity and expanding the applications of LIPSS. It not only overcomes the limitations associated with the monotonous structural type of 1D gratings in LIPSS but also offers a versatile means to engineer and customize the properties of thin-film materials. The increased range of structural possibilities and control over orientations pave the way for a great variety of applications,including surface modification,bionic structural coloration, high-precision detection,photonics,and optoelectronics. The findings presented in this study contribute to advancing laser nanopatterning techniques and provide valuable insights for future research in laser nanofabrication,a rapidly evolving field.

Large‐scale nanopatterning at low cost and high throughput is crucial to the practical applications of metasurfaces. Phase‐change materials equipped in these metasurfaces as modulation layers or resonators are generally applied to achieve a tunable function and have attracted significant attention. Here, an efficient method is developed by combining ultrafast laser localized modification/ablation and subsequent etching to fabricate nanostructures on a phase‐change material, Ge 2 Sb 2 Te 5 (GST), over a wafer‐sized area. The localized laser treatments under gradually increased laser fluences contribute to the variety of achievable nanostructures including disk and ring structures, whose feature sizes and periods can be tuned by adjusting laser parameters and subsequent etching conditions. A mid‐infrared metasurface absorber is designed and fabricated by using the GST ring units as resonators. Notably, varying the geometrical features of rings allows generating dual‐band and tri‐band absorption peaks in the mid‐infrared spectral range, whose peak absorptivity can reach ≈92%. By converting GST from amorphous to crystalline state, a broad absorption spectral redshift of 700 nm is achieved. The large‐area high‐throughput fabrication together with high‐absorption design demonstrates their potential in mass production of phase‐change metasurface‐based absorbers.

This paper proposes a one-step maskless 2D nanopatterning approach named self-aligned plasmonic lithography (SPL) by line-shaped ultrafast laser ablation under atmospheric conditions for the first time. Through a theoretical calculation of electric field and experimental verification, we proved that homogeneous interference of laser-excited surface plasmon polar-itons (SPPs) can be achieved and used to generate long-range ordered 2D nanostructures in a self-aligned way over a wafer-sized area within several minutes. Moreover, the self-aligned nanostruc-tures can be freely transferred between embossed nanopillars and engraved nanoholes by modulating the excitation intensity of SPPs interference through altering the incident laser energy. The SPL technique exhibits further controllability in the shape, orientation, and period of achievable nanopatterns on a wide range of semiconductors and metals by tuning processing parameters. Nanopatterned films can further act as masks to transfer structures into other bulk materials, as demonstrated in silica.

To improve the fabrication qualities and service performance of optical glass, the mechanical response mechanisms of two typical optical glass materials, high purity fused silica (HPFS) and soda-lime silica glass (SLSG), are investigated by nanoindentation experiments under loads below 500 mN. The mechanical properties of glass are reflections of its molecular structure. The molecular structure of HPFS is an amorphous SiO2 3D crosslink network structure with free volume and nonbridging oxygens (NBOs). For SLSG, due to the metallic ions packed into the free volume of the SiO2 network and the directionless property of the ionic bonds, its elastic modulus, Poisson's ratio and densification deformation resistance are higher than those of HPFS. The hardness and shear flow resistance of SLSG are lower than those of HPFS. An analytical model of the strain field after the nanoindentation unloading process was developed considering the permanent densification deformation. The mechanisms of the sink-in and pile-up formations and crack nucleation were explored using the analytical model of the strain field. The borderline cracks nucleate at the sinking region of the HPFS during the unloading process due to the free volume stacked at the surface. The mechanisms of radial crack nucleation in SLSG are the tensile stress concentration at the elastic-plastic interface near the surface induced by residual stress.

Since the discovery of graphene in 2004, there has been a great interest in two-dimensional (2D) materials from both the academic community and the semiconductor industry. In this work, we study various 2D materials and 2D heterostructures, aimed towards large-area device fabrication. Through detailed experimental work and extensive first-principle calculations, we determined the lowest energy structure for the interface of graphene formation on the C-face of SiC. The lowest energy structure contains > 1 monolayer of Si at the interface, forming an adatom-on-adlayer structure. Low-energy electron microscopy (LEEM) was employed to study properties of 2D heterostructures such as graphene–WSe2 and graphene–MoS2. Work function differences from the layers were extracted and band alignments were obtained, from which the nature of the contact at the interface was revealed. The electrical contact was found to be dependent on the constituent 2D layers of the heterostructures, as well as on the doping of the 2D layers. Finally, we consider simulation of devices made with 2D materials. We focus on interlayer tunneling field-effect transistors (TFETs) using 2D materials as the drain and source electrodes. By employing the first-principles density-functional-theory (DFT) wavefunctions, in the Bardeen tunneling formalism, we develop a “DFT-Bardeen” method that permits the computation of current-voltage characteristics in interlayer TFETs with reliable values for the magnitude of the currents. This method allows incorporation of differing materials into the source and drain electrodes, i.e. with different crystal structure, lattice constants, and/or band structure. Large variations in tunneling current were found, depending on the 2D materials being used. It is shown that the DFT-Bardeen method takes into account effects that are beyond simple lateral-momentum conservation, including the detailed symmetry and form of the wavefunctions. Predicted values for the tunneling current, including the subthreshold swing and the ON current, are compared with benchmark values for low-power digital applications.