Additive manufacturing最新文献_第5页

Hydrophilic silicone-based ink derived from amphiphilic siloxane oligomers for the vat photopolymerization printing of embedded-channel fluidic devices

IF 10.3 1区工程技术 Q1 ENGINEERING, MANUFACTURING

Additive manufacturing

Pub Date : 2025-02-05 DOI: 10.1016/j.addma.2025.104691

Li Yan Wong , Sayan Ganguly , Xiaowu (Shirley) Tang

The emergence of vat photopolymerization (VP) printing as an alternative fabrication method for fluidic devices has led to the rapid development of silicone-based resin material. However, most silicone-based resin materials are hydrophobic in nature, rendering them unsuitable for biomedical applications without post-processing. Herein, we introduce a new type of hydrophilic silicone-based resin material derived from vinyl-terminated amphiphilic siloxane oligomers, acrylamide, and glycidyl methacrylate, for the printing of fluidic devices. We demonstrate the strategy to overcome the challenges associated with amphiphilic-based formulation by adjusting the amphiphilic siloxane oligomer conformation with appropriate solvent blend, resulting in a silicone-based resin material with low pre-gel viscosity, high transparency, and hydrophilic characteristics. Besides, the developed material exhibits tunable elastic properties, excellent polar solvent resistance, and good biocompatibility. Upon photocuring depth tuning, the developed material displays high printing accuracy down to 200 µm in width and 50 µm in height. The material’s ability to replicate embedded fluidic channels with diverse shapes in one-step printing further shows its potential for fluidic device fabrication. The printed devices were revealed to be highly functional with the capability to process fluid at an elevated temperature of up to 100 ºC for 24 hours and a continuous flow rate of up to 20 mL/min. Further demonstration of the hydrogel beads synthesis for drug encapsulation reveals the feasibility of the printed device for real-world biomedical applications. The successful VP printing of hydrophilic silicone-based embedded-channel fluidic devices opened up new avenues for the fabrication of silicone-based fluidic devices for biomedical applications.

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引用次数: 0

Printability criterion and filler characteristics model for material extrusion additive manufacturing

IF 10.3 1区工程技术 Q1 ENGINEERING, MANUFACTURING

Additive manufacturing

Pub Date : 2025-02-05 DOI: 10.1016/j.addma.2025.104651

James J. Griebler , Alexander S. Tappan , Simon A. Rogers , Anne M Grillet , Jessica W. Kopatz

Material extrusion is an additive manufacturing technique that enables the creation of reproducible and complex hardware by depositing a viscous, shear-thinning ink onto a substrate in a custom-pattern via extrusion through a syringe. The ability of an ink to be extruded onto a substrate in many layers and maintain the desired shape is what defines printability. Printability has historically been investigated in an iterative manner by formulating and printing inks and then performing postmortem analysis of final parts. Highly concentrated pastes continue to pose issues for practitioners as the effect of filler morphology and size dispersity on the ink rheology and corresponding printability is not well understood. A printability criterion based on the particle filler’s maximum packing fraction was recently proposed to provide a general framework to understand printability of particle-filled inks. Inks were found to be printable if the particle loading was within 90–94 % of the maximum packing fraction of the particle. Here we expand on that work to validate the generality of the maximum packing fraction criterion by testing with 10 new single and multimodal particle fillers. The maximum packing fraction calculated from small amplitude oscillatory shear experiments and is found to correctly predict the printability range for all inks. We then utilize statistical methods to develop a filler characteristics model to predict the maximum packing fraction from particle analysis alone. These two methods paired together can significantly speed up development of new inks, increase the performance of material extrusion printing, and improve the stability of printed parts, with less wasted time and materials.

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引用次数: 0

2D carbon microlattices: A flexible, self-supporting, full-carbon building block

IF 10.3 1区工程技术 Q1 ENGINEERING, MANUFACTURING

Additive manufacturing

Pub Date : 2025-02-05 DOI: 10.1016/j.addma.2025.104695

Akira Kudo , Kazuya Omuro , Kaisei Furudate , Shinnosuke Kamohara , Farooq I. Azam , Yuta Yamamoto , Kota Matsuhashi , Ryotaro Kawashima , PJ Tan , Federico Bosi , Mingwei Chen

This work presents a demonstration of fabrication and characterization of 2D carbon microlattices (2D-CMLs) with tailored physical properties. The 2D-CMLs are composed of a thin film of pyrolytic carbon embedded with square and diamond micropatterns and variable thickness to tune its mechanical and functional response. The 2D-CMLs can be handled without substrate, springing elastically, bearing load and yet classifiable as bulk carbon materials rather than assemblies of nanocarbons. Utilizing vat photopolymerization (VPP), a reproducible fabrication process for 2D-CMLs is developed, which ensures the absence of apparent structural distortions such as wrinkles, curling, and other off-plane deformations during and after printing as well as pyrolysis. The resulting 2D-CMLs have relative densities

\bar{ρ}

∼0.6 and exhibit remarkable electrical conductivity, with values ranging from σ_e= 10,000–13,000 S･m⁻¹. Mechanical properties are excellent as well, reaching tensile strength σ= 27.35 ± 3.08 MPa and stiffness E = 7.68 ± 2.18 GPa for the thick diamond pattern, and σ= 63.32 ± 5.75 MPa and E = 16.12 ± 2.81 GPa for the thin square pattern. Moreover, the 2D-CMLs endure 1000 cycles of bending larger than 90˚ without mechanically degrading. These properties highlight the suitability of our 2D-CMLs for applications requiring multifunctional properties, such as conductivity, strength and flexibility. The outcomes of this study hold significant implications for research aiming at various applications such as flexible electrodes, mechatronics, and sensing, especially under extreme conditions where non-crystalline carbon can be more stable than metals and other popularly used materials.

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引用次数: 0

Quantifying residual orientation and thermal stress contributions to birefringence in the material extrusion of polylactide

IF 10.3 1区工程技术 Q1 ENGINEERING, MANUFACTURING

Additive manufacturing

Pub Date : 2025-02-05 DOI: 10.1016/j.addma.2025.104652

Anthony P. Kotula , Benjamin E. Dolata , Yoontae Kim , Sara V. Orski , Jonathan E. Seppala

Material extrusion is a common additive manufacturing process that subjects polymers to non-steady deformation and thermal processing to build a customized part. The mechanical properties of these parts are often worse than those of injection-molded specimens due to failures at or near the weld zone between extrudate layers. Chain orientation is often cited as a contribution to mechanical weakness at the weld, and it is therefore of critical importance to develop strategies to quantify the magnitude and location of residual chain orientation as a function of printing conditions. Here we use birefringence imaging to characterize the spatial variation in residual stress and residual chain orientation in a glassy polylactide. A combination of retardance measurements and sample thickness measurements provide a measure of birefringence as a function of position. As-printed samples show a nearly uniform birefringence background of approximately

7 \times 1 0^{- 5}

and higher birefringence near the weld region at lower nozzle temperatures and faster printing speeds. We propose two origins to the birefringence: one due to residual chain orientation, and the other due to residual stresses that occur when the sample cools non-uniformly on the build plate. Annealing the sample at 65 °C (slightly above the glass transition temperature) allows us to relax the residual stress without removing the orientation-based birefringence or crystallizing the sample. The residual orientation shows a strong power-law dependence on the Weissenberg number based on the characteristic timescales for flow in the nozzle and polymer chain reptation.

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引用次数: 0

Suspended bioprinting with in-situ elasticity monitoring using the assessment of shear wave phase velocity

IF 10.3 1区工程技术 Q1 ENGINEERING, MANUFACTURING

Additive manufacturing

Pub Date : 2025-02-05 DOI: 10.1016/j.addma.2025.104667

Garin Kim , Dageon Oh , Dasong Kim , Ganghak Lee , Sang-Hyug Park , Changhan Yoon , Seung Yun Nam

Suspended bioprinting has recently emerged as a promising alternative for fabricating intricate tissue-engineered scaffolds by enabling the precise deposition of low-viscosity bioink within a support bath, overcoming the limitations of conventional bioprinting methods. However, the dynamic monitoring of scaffold mechanical properties during fabrication remains a significant challenge. This study introduces a novel approach for suspended bioprinting with in-situ elasticity monitoring (SBEM), leveraging ultrasound shear wave elastography to nondestructively and dynamically assess the elastic properties of the bioprinted constructs. Using a custom-designed 3D bioprinting system, alginate and gelatin methacrylate (GelMA) scaffolds with varying cellulose nanocrystal concentrations and diverse geometries were fabricated in a Carbopol support bath. Phase velocities of shear waves were tracked and analyzed to estimate the storage moduli, validated against conventional rheometry. The SBEM approach demonstrated high temporal resolution in monitoring of elasticity changes during photocrosslinking. Additionally, cell-laden GelMA scaffolds maintained high cell viability after the measurement, confirming the biocompatibility of the technique. This approach addresses critical limitations in real-time mechanical monitoring, offering a scalable, nondestructive solution for optimizing scaffold properties during suspended bioprinting. The SBEM method holds significant potential to advance precision and quality control in tissue engineering applications.

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引用次数: 0

Super capillary performance of hybrid-structured wicks additively manufactured via laser powder bed fusion

IF 10.3 1区工程技术 Q1 ENGINEERING, MANUFACTURING

Additive manufacturing

Pub Date : 2025-02-05 DOI: 10.1016/j.addma.2025.104653

Xiaoqiang Peng , Guoliang Huang , Huan Chen , Qian Duan , Ke Huang

The capillary performance coefficient (K/R_eff) is a crucial performance indicator of the wick, a key component of high-performance heat pipes. However, it is difficult to enhance the permeability (K) and capillary pressure (

Δ P_{cap}

) at the same time. A wick with channels and porous hybrid structure was fabricated using Laser Powder Bed Fusion (LPBF) to achieve superior capillary performance. The channel structure ensures excellent permeability (K), while the porous structure offers high capillary pressure, which is further enhanced by the corner flow effect. The optimal structure, featuring a 0.6 mm square channel and 70.99 % porosity, achieved an ultra-high capillary performance of 3.24 × 10⁻⁶ m, which is 106.3 % higher than the previously reported best value. This study introduces a novel design concept and preparation method for high-performance heat pipes.

引用次数: 0

A new temperature index for build orientation optimization in powder bed fusion additive manufacturing

IF 10.3 1区工程技术 Q1 ENGINEERING, MANUFACTURING

Additive manufacturing

Pub Date : 2025-02-05 DOI: 10.1016/j.addma.2025.104660

A. González, R. Barea, S. Corbera

In Additive Manufacturing (AM) technology, part orientation holds a significant influence on various aspects including manufacturing time, support requirements and thermo-mechanical properties. The research specifically examines the crucial role of temperature in determining metallic part orientation for AM. With the aim of optimizing part orientation while temperatures are minimized even so, we introduced a novel thermal index. This index is able to quantify temperature changes upon rotating the part and comprises multiple sub-indices (area ground, circle, height and angle) derived from geometrical information extracted from STL (Standard Triangle Language) files. In order to assess the effectiveness of the thermal index, a combination of finite element method (FEM) and genetic algorithm (GA) techniques to solve the orientation problem is here performed. In this frame, a 360° rotation of the part for comparative analysis was conducted between the solutions obtained from the thermal index and those from FEM simulations. This contribution comprises two cases studies: a cone and a sand clock. The obtained results demonstrate a correlation between the thermal index and FEM-calculated temperature during the AM process. Notably, the highest thermal index (1.8 for the cone and 2.0 for the sand clock) corresponds to the lowest part temperatures (54°C for the cone and 53°C for the sand clock). Due to the simplifications of using this index, the time required to locate the part was significantly reduced by 96 % for the cone (to 4 minutes) and by 53 % for the sand clock (to 21 minutes) compared to the FEM. Furthermore, we validated the thermal index solving the part orientation problem for an industrial part and a foot orthosis.

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引用次数: 0

Facile construction of intelligent flexible double layer honeycomb sandwich structure for tunable microwave absorption by 4D printing

IF 10.3 1区工程技术 Q1 ENGINEERING, MANUFACTURING

Additive manufacturing

Pub Date : 2025-02-05 DOI: 10.1016/j.addma.2025.104661

Wei Xiao , Shaoqi Shi , Pei Liu , Zhilei Hao , Zhaoxia Tian , Qingqing Gao , Kai Xu , Yinxu Ni , Jin Chen , Changtian Zhu , Zhixiang Li , Gaojie Xu , Hui Zhang , Fenghua Liu

The integration of structure and material can endow microwave absorbers with excellent performance and broad application fields. However, its integrative manufacturing is extremely challenging, especially for the integration of functional materials and intelligent structures. In this context, the liquid crystal display (LCD) 4D printing was used to construct a kind of intelligent flexible double layer honeycomb sandwich structure by integrating multifunctional MXene@flake carbonyl iron powder (FCIP) and shape memory polymers (SMPs) resin. By controlling the applied time of the magnetic field, the structure with shape memory effect (SME) will be recovered to different radius of curvature (R) and center angle (α), which can endow the device with different absorption strengths and effective absorption bandwidth (EAB). When the α and R of the structure are 65.2° and 16.7 cm, the minimum reflection loss (RL_min) measured by the bow method is −50.87 dB, and the EAB (RL < −10 dB) reaches 13.8 GHz covering the C, X, and Ku bands. In addition, the applicability of smart structure devices in stealth technology is further confirmed by radar cross section (RCS) simulation, which is consistent with the conclusion of the measured results. This work enables the potential for rapid manufacturing of an intelligent, flexible, and ultra-broadband strong microwave absorbing device with integrated structure and function by 4D printing, which can be used in smart anti electronic reconnaissance, flexible wearable devices, and stealth technology.

{"title":"Facile construction of intelligent flexible double layer honeycomb sandwich structure for tunable microwave absorption by 4D printing","authors":"Wei Xiao , Shaoqi Shi , Pei Liu , Zhilei Hao , Zhaoxia Tian , Qingqing Gao , Kai Xu , Yinxu Ni , Jin Chen , Changtian Zhu , Zhixiang Li , Gaojie Xu , Hui Zhang , Fenghua Liu","doi":"10.1016/j.addma.2025.104661","DOIUrl":"10.1016/j.addma.2025.104661","url":null,"abstract":"<div><div>The integration of structure and material can endow microwave absorbers with excellent performance and broad application fields. However, its integrative manufacturing is extremely challenging, especially for the integration of functional materials and intelligent structures. In this context, the liquid crystal display (LCD) 4D printing was used to construct a kind of intelligent flexible double layer honeycomb sandwich structure by integrating multifunctional MXene@flake carbonyl iron powder (FCIP) and shape memory polymers (SMPs) resin. By controlling the applied time of the magnetic field, the structure with shape memory effect (SME) will be recovered to different radius of curvature (<em>R</em>) and center angle (<em>α</em>), which can endow the device with different absorption strengths and effective absorption bandwidth (EAB). When the <em>α</em> and <em>R</em> of the structure are 65.2° and 16.7 cm, the minimum reflection loss (<em>RL</em><sub><em>min</em></sub>) measured by the bow method is −50.87 dB, and the EAB (<em>RL</em> < −10 dB) reaches 13.8 GHz covering the C, X, and Ku bands. In addition, the applicability of smart structure devices in stealth technology is further confirmed by radar cross section (RCS) simulation, which is consistent with the conclusion of the measured results. This work enables the potential for rapid manufacturing of an intelligent, flexible, and ultra-broadband strong microwave absorbing device with integrated structure and function by 4D printing, which can be used in smart anti electronic reconnaissance, flexible wearable devices, and stealth technology.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"99 ","pages":"Article 104661"},"PeriodicalIF":10.3,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137439","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Localized strengthening of triply periodic minimal surface lattice structures via tuning the internal material distribution at the grain level

IF 10.3 1区工程技术 Q1 ENGINEERING, MANUFACTURING

Additive manufacturing

Pub Date : 2025-02-05 DOI: 10.1016/j.addma.2025.104663

Dien Hu , Jianying Wang , Zhirong Liao , M.W. Fu

Grain coarsening delivers the potential to enhance the multifunctional performances of triply periodic minimal surface (TPMS) structures, such as thermal and electrical conductivity, but it usually results in a weakening effect on the strength of the components. In this research, an abnormal phenomenon of coarse grains and slender walls-induced mechanical strengthening behavior was observed in the stainless steel 316 L TPMS structures fabricated via micro-laser powder bed fusion (μLPBF). The results indicate that a homogenized internal material distribution at the grain level leads to obvious localized strengthening behaviors in the TPMS structures during the localized and densification stage in the compression process. As the grains become coarser or the walls become thinner, the deformation mode of the TPMS structures transforms from the localized collapse deformation to the localized coordinated deformation, in which a homogeneous internal grain distribution is triggered by grain coarsening and wall thinning, promoting a homogeneous stress distribution. Particularly, Diamond (D)-type structures with the middle grains of 25.7 μm in the deformation direction show a 2.32 % enhancement in the energy absorption capacity compared to that of fine-grained (20.2 μm) components. This research outlines a guideline for acquiring an excellent synergy of the mechanical properties and multifunctional performances of the TPMS structures.

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引用次数: 0

Influence of architecture and temperature on the critical strain for serrated flow in additively manufactured Inconel 718 lattices

IF 10.3 1区工程技术 Q1 ENGINEERING, MANUFACTURING

Additive manufacturing

Pub Date : 2025-02-05 DOI: 10.1016/j.addma.2025.104676

S. Sahoo , Z. Chen , X. Jin , D. Mordehai , M. Haranczyk , M.T. Pérez-Prado

This work aims to investigate the influence of architecture and testing temperature (T) on the critical strain for serrated flow (ε_c) in Inconel 718 additively manufactured lattices. Three BCC lattices with different strut and cell dimensions were fabricated by laser powder bed fusion (LPBF) and they were tested in uniaxial compression at 25, 300, 450 and 600°C at an initial strain rate of 10⁻³ s⁻¹. Serrated flow was observed in the three BCC lattices at T ≥ 300 °C and ε_c was measured for each lattice architecture and temperature. At a fixed T ε_c is inversely proportional to the lattice relative density and for each investigated lattice architecture ε_c exhibits the lowest value at 450°C. Finite element modeling (FEM) was utilized to calculate the local stress distributions during uniaxial compression of the BCC lattices, revealing that the onset of serrated flow requires an activation volume fraction of material (V_f*) to be subjected to a local stress exceeding a threshold stress (σ_th). The values of V_f* and σ_th at 300, 450 and 600°C were calculated from the FEM simulations of the BCC lattices and they were used to accurately predict ε_c in an LPBF-manufactured FCCXYZ lattice at similar testing conditions. Our results suggest that the inverse relationship between ε_c and the lattice relative density is explained by the fact that lighter lattices require higher nominal strains to reach V_f*. Conversely, the variation of ε_c with temperature is attributed to changes in V_f*, as σ_th remains essentially constant at the investigated temperatures.

{"title":"Influence of architecture and temperature on the critical strain for serrated flow in additively manufactured Inconel 718 lattices","authors":"S. Sahoo , Z. Chen , X. Jin , D. Mordehai , M. Haranczyk , M.T. Pérez-Prado","doi":"10.1016/j.addma.2025.104676","DOIUrl":"10.1016/j.addma.2025.104676","url":null,"abstract":"<div><div>This work aims to investigate the influence of architecture and testing temperature (T) on the critical strain for serrated flow (ε<sub>c</sub>) in Inconel 718 additively manufactured lattices. Three BCC lattices with different strut and cell dimensions were fabricated by laser powder bed fusion (LPBF) and they were tested in uniaxial compression at 25, 300, 450 and 600°C at an initial strain rate of 10<sup>−3</sup> s<sup>−1</sup>. Serrated flow was observed in the three BCC lattices at T ≥ 300 °C and ε<sub>c</sub> was measured for each lattice architecture and temperature. At a fixed T ε<sub>c</sub> is inversely proportional to the lattice relative density and for each investigated lattice architecture ε<sub>c</sub> exhibits the lowest value at 450°C. Finite element modeling (FEM) was utilized to calculate the local stress distributions during uniaxial compression of the BCC lattices, revealing that the onset of serrated flow requires an activation volume fraction of material (V<sub>f</sub>*) to be subjected to a local stress exceeding a threshold stress (σ<sub>th</sub>). The values of V<sub>f</sub>* and σ<sub>th</sub> at 300, 450 and 600°C were calculated from the FEM simulations of the BCC lattices and they were used to accurately predict ε<sub>c</sub> in an LPBF-manufactured FCCXYZ lattice at similar testing conditions. Our results suggest that the inverse relationship between ε<sub>c</sub> and the lattice relative density is explained by the fact that lighter lattices require higher nominal strains to reach V<sub>f</sub>*. Conversely, the variation of ε<sub>c</sub> with temperature is attributed to changes in V<sub>f</sub>*, as σ<sub>th</sub> remains essentially constant at the investigated temperatures.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"99 ","pages":"Article 104676"},"PeriodicalIF":10.3,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137891","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0