A panoramic overview of subtractive, additive, and formative manufacturing of functional glass micro/nanostructures for a broad range of applications, highlighting the development lines and future ...trends of different glass micro/nanomanufacturing technologies. SM: subtractive manufacturing; AM: additive manufacturing; FM: formative manufacturing; USM: ultrasonic machining; IBM: ion beam machining; LBM: laser beam machining; EBM: electron beam machining; AJM: Abrasive jet machining; fs LAWE: femtosecond laser-assisted wet etching; LAFLD: liquid-assisted fs laser drilling; LIBE: laser-induced backside etching; PE: plasma etching; SLS: selective laser sintering; DED: directed energy deposition; DIW: direct ink writing; DIW: direct ink writing; SLM: selective laser melting; FDM: fused deposition modeling; SLA: stereolithography; SL: sheet lamination; DLP: digital light processing; TPP: two-photon polymerization; Micro-CAL: microscale computed axial lithography; SI: soft lithography; NI: nanoimprinting; UV: ultrasonic vibration; PGM: precision glass molding; IM: injection molding; EUV: extreme ultraviolet; FIB: focused ion beam; FEB: focused electron beam; FPB: focused proton beam; Tg: glass transition temperature.
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•A panoramic overview of glass micro/nanomanufacturing techniques is presented, covering subtractive, additive and formative manufacturing.•Essential features of glass micro/nanomanufacturing techniques are evaluated to highlight their fabrication capabilities and current challenges.•Future prospects are discussed to highlight potential opportunities to push glass manufacturing toward higher resolution, accuracy and efficiency.
The ever-increasing demands for miniature integrated optics, mechanics, electronics, and biofluidics have generated great interest in high-performance glass components featuring functional micro/nanostructures. Focusing on micro/nanostructuring of optical glass, many landmark processing techniques have been developed. However, due to notable differences in the capabilities of these techniques, researchers often encounter difficulties in selecting the appropriate glass feedstock or determining the optimal/complementary strategy for achieving a specific production task with desired resolution, accuracy, and efficiency. To shed light on potential solutions, this paper presents a state-of-the-art review that covers subtractive, additive, and formative manufacturing of functional micro/nanostructures using the broadest forms of glass feedstocks (including blocks, powders, and precursors). Initiating with a complete technical classification, the fundamentals, developments, and recent breakthroughs in micro/nanostructuring of glass are comprehensively outlined. Subsequently, the essential features (including spatial resolution, surface finish, accuracy, and efficiency) of the collected glass micro/nanomanufacturing techniques are comparatively evaluated, followed by detailed discussions of their capabilities and current challenges. Finally, future prospects are summarized to highlight potential opportunities and directions in glass micro/nanofabrication. This review will offer a panoramic guideline to the selection and innovation of glass materials and processing strategies for application-oriented precision and efficient manufacturing of diverse glass-based functional micro/nanostructures.
•A high-order differential interpolation curve is first constructed by using basis functions on each node.•An adjustable cam curve is then reconstructed by adding variable shape factors on critical ...nodes.•A high-speed cam curve with high fidelity, high-order continuity and low peak jerk is developed.
Mathematical defects of general cam curves such as high-order discontinuity and overlarge peak values often bring excessive transmission errors and vibrations to high-speed cam-follower systems. A comprehensive method is proposed in this study to develop high-speed cam curves with preferable mathematical characteristics. A high-order differential interpolation curve is first constructed by using nodal basis functions to accurately match with the multi-order derivatives on multiple nodes. A flexible cam curve is then reconstructed by adding variable shape factors on critical nodes for further shape adjustments. Numerical cases indicate that the proposed method can not only help construct a faithful cam curve satisfying all the given constraints for displacement, velocity, acceleration and jerk, but also effectively reconstruct a high-order continuous cam curve with lower peak values for high-speed precision cam mechanisms. The proposed method has been demonstrated to be effective and applicable in user-oriented reverse design, modification, and optimization of high-speed cam curves.
This paper aims to explore the fatigue life estimation approach of welded joints with precrack under coupled impact and fatigue loading, and the base metal is dissimilar 5083H111 and 5754 aluminum ...alloy. Impact tests are first carried out on the dissimilar lightweight materials welded joint with precrack located in the middle of the specimen, and a stress and strain field is obtained to determine the fatigue damage model parameters by using finite element dynamic analysis to simulate the impact process. Based, on the S-N curve of welded joints, the predicted life expectancy is found to be inconsistent with the experimental results. According to the continuum damage mechanics, the lifetime assessment model is presented to calculate both impact and fatigue damage. The estimated results agree well with the experimental ones.
Pre-loading on engineering materials or structures may produce pre-strain, especially plastic strain, which would change the fatigue failure mechanism during their service time. In this paper, an ...energy-based method for fatigue life prediction on high-strength-steel welded joints under different pre-strain levels was presented. Tensile pre-strain at three pre-strain levels of 0.2%, 0.35% and 0.5% was performed on the specimens of the material Q345, and the cyclic stress and strain responses with pre-loading were compared with those without pre-loading at the same strain level. The experimental work showed that the plastic strain energy density of pre-strained welded joints was enlarged, while the elastic strain energy density of pre-strained welded joints was reduced. Then, based on the strain energy density method, a fatigue life estimation model of the high-strength-steel welded joints in consideration of pre-straining was proposed. The predicted results agreed well with the test data. Finally, the validity of the developed model was verified by the experimental data from TWIP steel Fe-18 Mn and complex-phase steel CP800.
Aim:
Chitinase 3-like 1 (CHI3L1) has the potential to prompt proliferation and angiogenic formation. Interleukin-13 receptor α2 (IL-13Rα2) was regarded as a receptor of CHI3L1; however, it is unknown ...whether CHI3L1 adjusts the neovascularization in late atherosclerotic lesions of apoE
−/−
mice
via
IL-13Rα2.
Methods:
Silicone collars were placed around one of the common carotid arteries of apoE
−/−
mice fed with a high-fat diet. The mice were further injected with Ad.CHI3L1 alone or Ad.CHI3L1 + Ad.IL-13Rα2 shRNA through the caudal vein. The plaque areas in the whole aorta and aortic root were evaluated by Oil Red O staining and H&E staining. The contents of CD31, CD42b, and collagen in carotid plaques were investigated by immunohistochemistry and Masson trichrome staining. The role of CHI3L1 in migration and tube formation of human umbilical vein endothelial cells (HUVECs) was determined by transwell and Matrigel tests. The effect of CHI3L1 on the expression of AKT and extracellular signal-regulated kinase (ERK) was evaluated with the Western blot.
Results:
The plaque loads in the aorta were significantly more extensive in apoE
−/−
mice injected with Ad.CHI3L1 than those with Ad.CHI3L1 + Ad.IL-13Rα2 shRNA. CHI3L1 significantly increased the contents of CD31 and CD42b and decreased the element of collagen in late-stage atherosclerotic lesions of the carotid arteries. The effects of CHI3L1 on migration, tube formation, and upregulation of phospho-AKT and phospho-ERK of HUVECs were prohibited by inhibitors of phosphatidylinositol 3-kinase (PI3K) and mitogen-activated protein kinase kinase (MEK) as well as IL-13Rα2 shRNA.
Conclusion:
To some extent, CHI3L1 promotes migration and tube formation of HUVECs and neovascularization in atherosclerotic plaques possibly mediated by IL-13Rα2 through AKT and ERK signal pathways.
The optimal tuning of high-order motion parameters has emerged as a promising strategy for actively controlling the kinematics/dynamics of high-speed cam mechanisms. However, accomplishing this task ...remains challenging with current low-order interpolation or tuning methods. This study proposes an integrated high-order interpolation and tuning methodology for the optimal construction of high-speed motion curves. Initially, an explicit C4-spline interpolant (C4SI) is developed. This interpolant utilizes four-order continuous (C4) splines to synthesize a high-fidelity motion curve that satisfies the predefined motion constraints up to the fourth order, including dimensionless displacement, velocity, acceleration, jerk, and quirk. Concerning the reduction of motion peaks, a unique C4SI-based global kinematics optimization strategy is designed, using the definite integral of the motion curve (free of the time variable) as the objective function. This facile time-free optimization strategy could yield a simultaneous reduction in multiple motion peaks (up to five), which is currently inaccessible with conventional motion tuning strategies. Concerning the improvement of dynamic characteristics, the C4SI-based time-free global dynamics optimization of variable motion parameters is further performed. The results indicate that the optimized fourth-order motion curve offers minimal high-speed transmission error and residual vibration over the whole rise-dwell-return-dwell cycle, which outperforms the standard motion curves and other low-order counterparts.
This study proposes a new strategy for achieving rapid volumetric heating of moldable low-dielectric-loss glass over a wide temperature range using only microwave sources. As a proof of concept, both ...multi-physics modeling and experimental demonstration of microwave heating (MWH) of Pyrex 7740 glass are performed. The results reveal that there is an activation threshold of 400 °C for this glass, i.e., below this threshold the glass is mainly heated by SiC molds through interfacial heat transfer, while above it the glass can be directly heated by 2.45-GHz MWs through volumetric dielectric loss. As a result, the glass preform can attain an internal temperature of 727 °C (well above its transition point) within a short MWH process (130 s), at a low level of specific energy consumption (6.43 kW h/kg). The average volumetric heating rate of the glass is estimated as 5.44 °C/s, which outperforms the reported rates (2.00−3.60 °C/s) in previous precision glass molding (PGM) studies. Furthermore, the temperature difference in the entire glass can be minimized through MWH combined with post-annealing. With the demonstrated capabilities of instantaneous, volumetric, and selective heating, the proposed MWH strategy holds great promise in PGM and many other glass thermoforming sectors.
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Abstract
There is an urgent need for novel processes that can integrate different functional nanostructures onto specific substrates, so as to meet the fast-growing need for broad applications in ...nanoelectronics, nanophotonics, and flexible optoelectronics. Existing direct-lithography methods are difficult to use on flexible, nonplanar, and biocompatible surfaces. Therefore, this fabrication is usually accomplished by nanotransfer printing. However, large-scale integration of multiscale nanostructures with unconventional substrates remains challenging because fabrication yields and quality are often limited by the resolution, uniformity, adhesivity, and integrity of the nanostructures formed by direct transfer. Here, we proposed a resist-based transfer strategy enabled by near-zero adhesion, which was achieved by molecular modification to attain a critical surface energy interval. This approach enabled the intact transfer of wafer-scale, ultrathin-resist nanofilms onto arbitrary substrates with mitigated cracking and wrinkling, thereby facilitating the
in situ
fabrication of nanostructures for functional devices. Applying this approach, fabrication of three-dimensional-stacked multilayer structures with enhanced functionalities, nanoplasmonic structures with ∼10 nm resolution, and MoS
2
-based devices with excellent performance was demonstrated on specific substrates. These results collectively demonstrated the high stability, reliability, and throughput of our strategy for optical and electronic device applications.
Highlights
The critical surface energy interval enables near-zero adhesion.
Intact photoresist-based transfer printing replaces direct transfer of nanostructures.
Dry lift-off makes it easier to prepare metal nanostructures without adhesive layers.
High-fidelity
in-situ
fabrication is realized on difficult-to-process substrates.
Mass and large-area multiscale nanostructures are fabricated with high efficiency.
The effect and mechanism of trace amounts of Sr and Sc in the A380 alloy under ultrasonic vibration (ultraviolet) modification on the microstructure and mechanical properties were investigated. The ...results showed that the primary α phase in A380 could be refined by adding Sr and Sc under ultraviolet treatment, the secondary dendrite spacing decreased significantly, and the thick dendritic shapes transformed to tiny disperse isometric crystals. The highest ultimate tensile strength (about 302 MPa) was obtained by adding 0.2 Sr+0.4 Sc (wt%) and applying ultraviolet treatment. The highest hardness (about 113 BHN) and elongation (about 4.65%) were obtained by adding 0.15% Sr+0.3% Sc and applying ultraviolet treatment, and the minimum grain size (about 27 μm) and maximum shape factor (around 0.8) were obtained for the same composition.
Aiming at the problems of the work profile of globoidal cam in automatic tool changer（ ATC） is difficult to design,manufacture and both side of cam groove meshing with the roller in indexing ...period,taking the globoidal cam of a certain machining center as example,the motion and position relationship between globoidal cam and indexing plate are analyzed,the mathematical equation of globoidal cam contour surface is derived and modified. By using the segment modeling method,the cam profile curve groups in both indexing period and dwell period are created in Pro/E software. By the physical modeling of line and surface,the accurate 3D solid model of the globoidal cam is established. After globoidal cam profile performance analysis and machining practice,the designed globoidal cam model is verified to meet the design and machining requirements,which provides technical support for improving its finish grinding accuracy.
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