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OBATON, A. F., A. BERNARD, G. TAILLANDIER, and J. M. MOSCHETTA. "Fabrication additive : état de l’art et besoins métrologiques engendrés." Revue française de métrologie, no. 37 (March 30, 2015): 21–36. http://dx.doi.org/10.1051/rfm/2015003.
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OBATON, A. F., A. BERNARD, G. TAILLANDIER, and J. M. MOSCHETTA. "Erratum - Fabrication additive : état de l’art et besoins métrologiques engendrés." Revue française de métrologie, no. 41 (April 25, 2016): 41. http://dx.doi.org/10.1051/rfm/2016005.
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Millon, Célia, Arnaud Vanhoye, and Anne-Françoise Obaton. "Ultrasons laser pour la détection de défauts sur pièces de fabrication additive métallique." Photoniques, no. 94 (November 2018): 34–37. http://dx.doi.org/10.1051/photon/20189434.
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La fabrication additive (FA), notamment la FA de pièces métalliques, connait un essor dans les secteurs de pointe comme l’aéronautique ou le médical de par les possibilités accrues en termes de complexité géométrique, de fonctionnalités ou encore de personnalisation des pièces. Cependant, les poudres métalliques et la fusion laser mis en oeuvre dans certains procédés lors de la fabrication conduisent parfois à des défauts, comme par exemple des manques de fusion. Pour réduire les coûts de production engendrés par des pièces finies mais non conformes, la fabrication de ces pièces appelle à développer un contrôle en ligne. Les ultrasons laser (UL), non destructifs et sans contact, sont une piste prometteuse : ils combinent la sensibilité d’un contrôle par ultrasons avec la flexibilité d’un système optique.
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Camaraa, M., N. Loganathan, and A. Fischer. "Technologie additive : Impression de matériaux par jet d’encre pour l’électronique imprimée." J3eA 21 (2022): 1002. http://dx.doi.org/10.1051/j3ea/20221002.
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Nous présentons un enseignement sous forme de cours, Tps et projets tutorés sur le domaine de l’impression jet d’encre de matériaux pour l’électronique imprimée (réalisation de capteurs et d’OLED (organic light-emitting diode)). Nous aborderons avec les étudiants les enjeux de l’électronique imprimée comme fabrication additive ainsi que ses caractéristiques (Encre-Tête-Substrats). A travers les projets tutorés et les travaux pratiques, nous aborderons en salle blanche la technique de dépôt de matériaux par jets d’encres : de la conception à la caractérisation des couches imprimées en passant par la réalisation : traitement pré et post impression, mesure d’épaisseur et de résistivités d’encres conductrices.
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Gerges, Tony, Philippe Lombard, Bruno Allard, and Michel Cabrera. "Attirer l’étudiant vers l’électronique à l’aide de la plastronique 3D et de la fabrication additive." J3eA 21 (2022): 2047. http://dx.doi.org/10.1051/j3ea/20222047.
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L’enseignement de l’électronique se heurte à un manque d’appétence de la part des étudiants. Ouvrir le champ technologique vers la fabrication additive et la plastronique est de nature à solliciter de nouveau l’intérêt des étu-diants. Malheureusement il est délicat de donner un premier exemple pertinent qui confirme l’intérêt et mette les diffé-rents cours en perspective, car la plastronique balaie des connaissances allant des matériaux, à la chimie, la plasturgie, la conception mécanique 3D, etc. L’article présente un mini-projet sur la réalisation d’un dispositif plastronique à l’aide de la fabrication additive et de la métallisation autocatalytique, comme premier contact des étudiants avec les aspects tech-nologiques. Il s’agit de fabriquer une maquette de camion imprimée en 3D, qui embarque sur sa surface non plane un circuit électronique typique. Tout d’abord le schéma électronique et la conception mécanique sont réalisés et assemblés. L’objet est ensuite imprimé et les pistes sont métallisées. La maquette du camion est obtenue après le brasage des com-posants. Cette maquette vise à provoquer un questionnement de la part de l’étudiant et lui permettre de mieux position-ner le contenu des cours et travaux pratiques d’une formation spécialisée en plastronique.
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Quantin, Danièle. "Retour sur les Journées Annuelles de la SF2M 2019." Matériaux & Techniques 107, no. 6 (2019): N1. http://dx.doi.org/10.1051/mattech/2020010.
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Les Journées Annuelles de la SF2M 2019 se sont déroulées à Paris (Chimie Paris Tech) du 21 au 23 octobre. Plus de 150 participants ont pu assister à 50 présentations scientifiques dont 3 plénières, 1 conférence plénière sur l’histoire des matériaux et table ronde sur les carrières, organisée par le groupe « Jeunes » de la SF2M. Seize posters faisant l’objet d’un concours ont aussi été présentés. Les présentations scientifiques étaient regroupées en 3 thèmes génériques : Fabrication additive, de la fabrication de la matière première à la pièce fonctionnelle ; Ténacité et rupture brutale ; Mise en forme, microstructure et propriétés d’usage des superalliages base nickel polycristallins.
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Agrawal, Sanat, and Akshay Jain. "Physical Modelling of Nanda Devi National Park, a Natural World Heritage Site, from GIS Data." Cartographica: The International Journal for Geographic Information and Geovisualization 57, no. 2 (July 1, 2022): 179–94. http://dx.doi.org/10.3138/cart-2021-0025.
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Une méthode a été mise au point afin de produire, par fabrication additive (FA), un modèle physique du Parc national de Nanda Devi (PNND), site qui figure sur la Liste du patrimoine naturel mondial de l’UNESCO, afin de faciliter la communication entre les parties qui interviennent dans la gestion de la conservation de ce parc. Les données obtenues par SIG fournissent des valeurs d’élévation pour la surface du terrain uniquement et ne sont pas définies en 3D. Le fichier de format DEM ASCII XYZ est converti au format STL, en 3D, avec une base et des côtés. Les lacunes et les singularités dans les données sont prises en compte. La méthode par fabrication additive ouvre de vastes possibilités pour la conservation et la réhabilitation des sites de l’UNESCO. À partir de cette méthode, un modèle physique du PNAD a été créé. Le modèle a énormément de potentiel pour le suivi à long terme des sites du patrimoine mondial et de la chaine himalayenne. Il peut servir de moyen de communication efficace pour les gestionnaires de la conservation. Des modèles physiques des bassins des vallées glaciaires ou du pic de la Nanda Devi enrichiraient encore nos connaissances. Le travail de recherche pourrait s’étendre à la fabrication de modèles de plus grandes dimensions du PNND, ou à la modélisation de zones plus petites du PNND, en consultation avec les parties concernées.
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Antomarchi, Anne-Lise, Séverine Durieux, and Emmanuel Duc. "Impact de la fabrication additive sur la supply chain : état des lieux et diagnostics." Logistique & Management 28, no. 1 (November 8, 2019): 29–47. http://dx.doi.org/10.1080/12507970.2019.1682950.
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Nouri, Malek. "L’impression 3D en design: pour une future expérience créative en Tunisie." Revista de Ensino em Artes, Moda e Design 7, no. 3 (September 18, 2023): 1–19. http://dx.doi.org/10.5965/25944630732023e3369.
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L'architecture est profondément influencée par les nouvelles technologies, constamment mise à l'épreuve des innovations et des tendances en quête d'ancrage et de performance environnementale. Ces avancées technologiques fulgurantes ouvrent la voie à de nouvelles formes de créativité en design d'intérieur. L'impression 3D également connue sous le nom de fabrication additive ouvre la voie à une conception spatiale plus intelligente et plus efficace. La technologie d'impression 3D a déjà connu un succès dans le monde, le manque de connaissance et de sensibilisation à la technologie dans le secteur de la construction, les méthodes de caractérisation des matériaux et les questions de fabrication posent un réel problème aux architectes et aux designers d'intérieur en Tunisie. Les interrogations qui s’imposent concernent la possibilité d’utiliser la technologie dans la conception des espaces intérieurs, la place qu’occupe aujourd’hui l’innovation dans la création de nos espaces et comment penser l’intersection entre design et impression 3D dans la conception de nos espaces de vie? L'objectif de ce travail est d'identifier les enjeux de la conception architecturale créative et durable en Tunisie à travers l'impression 3D en recourant à une approche empirique fondée sur l'étude de cas et l'analyse de projets concrets. L'éducation en matière d'impression 3D nous permettra de réexaminer cette technologie innovante, qui pourrait apporter des solutions aux défis environnementaux et sociaux liés à la construction. Ce changement de paradigme va révolutionner notre façon de concevoir l'espace physique, l'architecture et le bâtiment dans un pays où l'architecture a été influencée par plusieurs civilisations.
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Masbernat, Raphaël, Églantine Bigot-Doll, Maxime Fouillat, Elisabeth Sulmont, François Pacquelet, Antoine Chevalier, Naomi Pereira, and Chloé Blanc. "Machines à voir, machines à penser : écosystème robotique situé pour la conception architecturale." SHS Web of Conferences 147 (2022): 06001. http://dx.doi.org/10.1051/shsconf/202214706001.
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L’équipe cobotique du MAP-Aria a développé un dispositif de prototypage robotique à petite échelle visant à exacerber les dimensions tactile et proprioceptive de l’expérience de conception. Nous programmons et expérimentons des protocoles de fabrication additive mis en orbite dans une boucle feedback en tant que capture analogique sur l’environnement par un robot 6-axes modifiant pas à pas la trajectoire du système. De ce « machine behavior » résulte un « design behavior » à travers la mise au point d’instruments haptiques et la production d’objets en série. Le processus de conception intègre alors dès ses premières itérations une perception approfondie des écarts et des résonances entre objets numériques simulés et artefacts physiques fabriqués. Navigant entre nécessité de simulation située et volonté de fiction, la mise en oeuvre de schèmes technologiques ouverts à la reprogrammation et à l’indétermination rencontre les activités fécondes de bricolage et d’improvisation, de spatialisation et de fabulation propres au moment de conception.
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Maurel, Alexis, Ana Cristina Martinez, Sylvie Grugeon, Stephane Panier, Loic Dupont, Michel Armand, Roberto Russo, et al. "(Battery Division Postdoctoral Associate Research Award Sponsored by MTI Corporation and the Jiang Family Foundation) 3D Printing of Batteries: Fiction or Reality?" ECS Meeting Abstracts MA2022-02, no. 3 (October 9, 2022): 214. http://dx.doi.org/10.1149/ma2022-023214mtgabs.
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Motivated by the request to build shape-conformable flexible, wearable and customizable batteries while maximizing the energy storage and electrochemical performances, additive manufacturing (AM) appears as a revolutionary discipline. Battery components such as electrodes, separator, electrolyte, current collectors and casing can be tailored with any shape, allowing the direct incorporation of batteries and all electronics within the final three-dimensional object. AM also paves the way toward the implementation of complex 3D electrode architectures that could enhance significantly the power battery performances. Transitioning from conventional 2D to complex 3D lithium-ion battery (LIB) architectures will increase the electrochemically active surface area, enhance the Li+ diffusion paths, thus leading to improved specific capacity and power performance [1]. Our recent modeling studies [2] involving the simulation of a classical Ragone plot illustrated that a gyroid 3D battery architecture has +158% performance at a high current density of 6C, in comparison to planar geometry. In this presentation, an overview of current trends in energy storage 3D printing will be discussed [3-11]. A summary of our recent works on lithium-ion battery 3D printing via Thermoplastic Material Extrusion / Fused Deposition Modeling will be presented [12-16]. The development of printable composite filaments (Graphite-, LiFePO4-, Li2TP-, PEO/LiTFSI-, SiO2-, Ag/Cu-based) corresponding to each part of a LIB (electrodes, electrolyte, separator, current collectors), and the importance of introducing a plasticizer (polyethylene glycol dimethyl ether average Mn 500 for polylactic acid) as an additive to enhance the printability will be addressed. Printing of the complete LIB in a single step using multi-material printing options, and the implementation of a solvent-free protocol [14] will also be discussed. Second part of this presentation will be dedicated to AM of batteries by means of Vat Photopolymerization (VPP) processes, including stereolithography, digital light processing and two-photon polymerization (offering a greater resolution down to 0.1μm), to print high resolution battery components [10]. Composite resins formulation approaches based on the introduction of solid battery particles or precursor salts will be introduced [17, 18]. Finally, an overview of our ongoing project dedicated to AM of sodium-ion batteries from resources available on the Moon and Mars will be presented. Due to its relative abundance in the Lunar regolith, the development of a composite photocurable resin loaded with TiO2 negative electrode material and conductive additives, to feed a VPP printer, will be discussed [18]. [1] Long et al., Three-dimensional battery architectures, Chemical Reviews 104(10) (2004) 4463-4492. [2] Maurel et al., Considering lithium-ion battery 3D-printing via thermoplastic material extrusion and polymer powder bed fusion, Additive Manufacturing (2020) 101651. [3] Maurel et al., Overview on Lithium-Ion Battery 3D-Printing By Means of Material Extrusion, ECS Transactions 98(13) (2020) 3-21. [4] Ragones et al., Towards smart free form-factor 3D printable batteries, Sustainable Energy & Fuels 2(7) (2018) 1542-1549. [5] Reyes et al., Three-Dimensional Printing of a Complete Lithium Ion Battery with Fused Filament Fabrication, ACS Applied Energy Materials 1(10) (2018) 5268-5279. [6] Yee et al., Hydrogel-Based Additive Manufacturing of Lithium Cobalt Oxide, Advanced Materials Technologies 6(2) (2021). [7] Saccone et al., Understanding and mitigating mechanical degradation in lithium–sulfur batteries: additive manufacturing of Li2S composites and nanomechanical particle compressions, Journal of Materials Research (2021). [8] Tagliaferri et al., Direct ink writing of energy materials, Materials Advances 2(2) (2021) 25. [9] Sun et al., 3D Printing of Interdigitated Li-Ion Microbattery Architectures, Advanced Materials 25(33) (2013) 4539-4543. [10] Maurel et al., Toward High Resolution 3D Printing of Shape-Conformable Batteries via Vat Photopolymerization: Review and Perspective, IEEE Access 9 (2021) 140654-140666. [11] Seol et al., All-Printed In-Plane Supercapacitors by Sequential Additive Manufacturing Process, Acs Applied Energy Materials 3(5) (2020) 4965-4973. [12] Maurel et al., Highly Loaded Graphite-Polylactic Acid Composite-Based Filaments for Lithium-Ion Battery Three-Dimensional Printing, Chemistry of Materials 30(21) (2018) 7484-7493. [13] Maurel et al., Three-Dimensional Printing of a LiFePO4/Graphite Battery Cell via Fused Deposition Modeling, Scientific Reports 9(1) (2019) 18031. [14] Maurel et al., Environmentally Friendly Lithium-Terephthalate/Polylactic Acid Composite Filament Formulation for Lithium-Ion Battery 3D-Printing via Fused Deposition Modeling, ECS Journal of Solid State Science and Technology 10(3) (2021) 037004. [15] Maurel et al., Poly(Ethylene Oxide)-LiTFSI Solid Polymer Electrolyte Filaments for Fused Deposition Modeling Three-Dimensional Printing, Journal of the Electrochemical Society 167(7) (2020). [16] Maurel et al., Ag-Coated Cu/Polylactic Acid Composite Filament for Lithium and Sodium-Ion Battery Current Collector Three-Dimensional Printing via Thermoplastic Material Extrusion, Frontiers in Energy Research 9(70) (2021). [17] Martinez et al., Additive Manufacturing of LiNi1/3Mn1/3Co1/3O2 battery electrode material via vat photopolymerization precursor approach, (submitted). [18] Maurel et al., Vat Photopolymerization Additive Manufacturing of Sodium-Ion Battery TiO2 Negative Electrodes from Lunar In-Situ Resources, (submitted).
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Nydegger, Mirco, Nikolaus Porenta, Maxence Menétrey, Souzan Hammadi, Alain Reiser, and Ralph Spolenak. "Electrohydrodynamic Redox 3D Printing: Confined Electroplating of Alloys for Additive Manufacturing at the Submicron Scale." ECS Meeting Abstracts MA2022-01, no. 22 (July 7, 2022): 1119. http://dx.doi.org/10.1149/ma2022-01221119mtgabs.
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Combining the unprecedented design freedom in microscale additive manufacturing (AM) with the ability to control the chemical nature of each printed voxel could unlock unique possibilities for tailoring mechanical, chemical, electrical, optical and magnetic properties of metal microstructures. A variety of techniques for micro- and nanoscale AM has been proposed for the fabrication of device-grade metals and alloys [1]. Electrochemical approaches to small-scale AM generally lead to superior microstructures (in terms of porosity and contamination) compared with techniques that transfer pre-synthesized materials [2]. The deposition of alloys with controlled composition, however, remains a challenge with electrochemical small scale AM techniques. In this talk, we will present our work on additive manufacturing of alloyed structures using electrohydrodynamic redox (EHD-RP) 3D printing [3]. EHD-RP is based on the deposition of solvent droplets containing metal ions onto a conductive substrate, where the solvent evaporates and the ions are reduced. In general, this technique allows the direct deposition of polycrystalline 3D metal structures with a resolution of approx. 250 nm and a feature size down to 100 nm. We will present our work in expanding the materials range of EHD-RP from the limited range reported previously to a wide range of metals and subsequently discuss in detail the direct deposition of alloys. As it will be shown, the approach of spatially confining electrodeposition enables the fabrication of multi-metal and alloyed structures with a chemical voxel size <400 nm, hence making a step towards chemically architected materials. We will show how we can control the composition of the deposited material and the challenges involved in its characterization. In summary, we present a novel approach to the bottom-up manufacturing of locally alloyed microstructures, adding an additional parameter in the design of novel nano- and microstructured inorganic materials. [1] L. Hirt, A. Reiser, R. Spolenak & T. Zambelli. Additive Manufacturing of Metal Structures at the Micrometer Scale. Adv. Mater., 29(17), 2017. [2] A. Reiser, R. Spolenak et al. Metals by Micro-scale Additive Manufacturing: Comparison of Microstructure and Mechanical Properties. Adv. Funct. Mater., 30, 1910491, 2020 [3] A. Reiser, M. Lindén, P. Rohner, A. Marchand, H. Galinski, A. S. Sologubenko, J. M. Wheeler, R. Zenobi, D. Poulikakos & R. Spolenak. Multi-metal electrohydrodynamic redox 3D printing at the submicron scale. Nat. Comm., 10(1):1-8, 2019. Figure 1
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Presciutti, Andrea, Elisa Gebennini, Federica Liberti, Francesca Nanni, and Mario Bragaglia. "Comparative Life Cycle Assessment of SLS and mFFF Additive Manufacturing Techniques for the Production of a Metal Specimen." Materials 17, no. 1 (December 23, 2023): 78. http://dx.doi.org/10.3390/ma17010078.
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This work is part of a research project aimed at developing a bio-based binder, composed mainly of polylactic acid (PLA), to produce Ti6Al4V feedstock suitable for use in MAM (Metal Additive Manufacturing) via mFFF (metal Fused Filament Fabrication), in order to manufacture a titanium alloy specimen. While in Bragaglia et al. the mechanical characteristics of this sample were analyzed, the aim used of this study is to compare the mentioned mFFF process with one of the most used MAM processes in aerospace applications, known as Selective Laser Sintering (SLS), based on the Life Cycle Assessment (LCA) method. Despite the excellent properties of the products manufactured via SLS, this 3D printing technology involves high upfront capital costs while mFFF is a cheaper process. Moreover, the mFFF process has the advantage of potentially being exported for production in microgravity or weightless environments for in-space use. Nevertheless, most scientific literature shows comparisons of the Fused Filament Fabrication (FFF) printing stage with other AM technologies, and there are no comparative LCA “Candle to Gate” studies with mFFF processes to manufacture the same metal sample. Therefore, both MAM processes are analyzed with the LCA “Candle to Gate” method, from the extraction of raw materials to the production of the finished titanium alloy sample. The main results demonstrate a higher impact (+50%) process for mFFF and higher electrical energy consumption (7.31 kWh) compared to SLS (0.32 kWh). After power consumption, the use of titanium becomes the main contributor of Global Warming Potential (GWP) and Abiotic Depletion Potential (ADP) for both processes. Finally, an alternative scenario is evaluated in which the electrical energy is exclusively generated through photovoltaics. In this case, the results show how the mFFF process develops a more sustainable outcome than SLS.
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DeWees, Rachel, Arjun Thapa, Jacek Bogdan Jasinski, and Mahendra Sunkara. "Silicon Nanotubes on Copper Films: Additive-Free Anode Material for Lithium-Ion Batteries." ECS Meeting Abstracts MA2023-01, no. 7 (August 28, 2023): 2887. http://dx.doi.org/10.1149/ma2023-0172887mtgabs.
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Thedevelopment of lightweight, long-lasting Li-ion batteries is of great technological importance for critical applications, including but not limited to aerospace and power grid applications. Increasing the specific capacity of the electrodes is the most direct strategy to increase the energy density of the battery. Currently, batteries with silicon anode materials have been commercially available only on a small scale or at a low composition of silicon. Great impact will be made when 100% silicon anode material can be fabricated at large scale. Specifically, the electric vehicle industry will experience disruption when a silicon solution enters the market which can offer durability as it delivers the expected high capacity. Silicon-based anode materials have a theoretical capacity an order of magnitude beyond the currently implemented graphitic materials- 3579 mAh/g when fully lithiated at room temperature to Li4Si15, as compared with 372 mAh/g. Silicon incorporates lithium into its microstructure as an alloying process as opposed to direct intercalation, like graphite; as such, a volume change of 300% causes mechanical degradation upon cycling if conventional processing is used. Nanoscale 0-D and 1-D materials have been shown to withstand volume expansion and enable Li-intercalation and de-intercalation reactions to occur; recent effective strategies include nanowires, nanoparticles embedded in polymeric matrices, and yolk-shell morphologies with carbon. [1-4] The abundance of silicon on earth is second only to oxygen; it makes up 28% by mass of the earth’s crust. The natural abundance, non-toxicity, extremely high specific capacity, low cost, chemical stability, and low average delithiation potential of silicon make it an ideal energy material. [5] Research interest has only increased over the last 15 years, as many simultaneous attempts are made at solving the challenges of nanoscale silicon- the successful execution of which will make large scale manufacturing of silicon anode materials possible. [6] The combination of nanosizing and engineering porosity within the silicon anode are the chief strategies to bring the cycle life necessary for commercialization. We report fabrication of anode material which consists of an additive free layer of silicon nanotubes bonded to copper foil, which has exhibited durability over 100 cycles. This promising novel silicon anode material has areal capacity of >2mAh·cm-2. [1] Keller, C., et al., Effect of Size and Shape on Electrochemical Performance of Nano-Silicon-Based Lithium Battery. Nanomaterials (Basel), 2021. 11(2). [2] Yang, K., et al., 3D growth of silicon nanowires under pure hydrogen plasma at low temperature (250 degrees C). Nanotechnology, 2021. 32(6): p. 065602. [3] Shi, J., et al., A surface-engineering-assisted method to synthesize recycled silicon-based anodes with a uniform carbon shell-protective layer for lithium-ion batteries. J Colloid Interface Sci, 2021. 588: p. 737-748. [4] Xiao Hua Liu, L.Z., Shan Huang, Scott X. Mao, Ting Zhu, and Jian Yu Huang, Size-Dependent Fracture of Silicon Nanoparticles During Lithiation. ACS Nano, 2012. 6(2): p. 1522-1531. [5] Naoki Nitta, F.W., Jung Tae Lee, and Gleb Yushin, Li-ion battery materials: present and future. Materials Today, 2015. 18(5). [6] Jaramillo-Cabanzo, D.F., et al., One-dimensional nanomaterials in lithium-ion batteries. Journal of Physics D: Applied Physics, 2021. 54(8). Fig. 1. Micro and nanostructure. Areal capacity. Figure 1
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Payne, Greg F. "(Invited) Electro-Bio-Fabrication of Soft Matter." ECS Meeting Abstracts MA2023-02, no. 22 (December 22, 2023): 1314. http://dx.doi.org/10.1149/ma2023-02221314mtgabs.
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Vision. Electrochemistry provides unique opportunities to couple top-down with bottom-up fabrication methods for the purpose of creating hydrogels with complex microstructures and bio-relevant functionalities.1 Thus, we envision that the coupling of electrochemistry with modern biological methods could enable a new additive manufacturing approach applicable to large-scale manufacturing yet simple and safe enough to be employed in publicly-available maker spaces. Electrochemistry as a “Signal-Generator” to Cue the Emergence of Structure and Function. Electrical inputs imposed at an electrode can result in the “transmission” of both electrical and chemical “signals”. The imposed electric field provides cues for charged polymers to migrate (i.e., electrophoresis), and in some cases, to alter their chain conformations (extended vs collapsed) and chain alignments. Electrochemical reactions at the electrode can generate chemical cues (e.g., pH gradients, diffusible oxidants/reductants and metal ions) that can induce polymers to undergo hierarchical assembly through physical, covalent and chelation mechanisms. Together, the electrical and chemical cues provide the opportunity to generate hydrogels with controlled microstructures. Biology as a Source of Materials and Mechanisms for Electro-assembly. Typically, biology achieves its immense morphological diversity using a small set of polymers (e.g., collagen, cellulose and chitin) that possess internal structural information for assembly. Biology then precisely imposes the contextual cues that control the emergence of higher-order structure from these biopolymers. Numerous studies from various laboratories have shown that several biopolymers can be cued by electrochemical inputs to reversibly self-assemble into organized supramolecular structures (e.g., hydrogels). Examples include proteins (collagen and silk) and polysaccharides (chitosan and alginate) that electro-assemble in response to modest imposed voltages often through pH-based neutralization mechanisms. Also important is that various groups using different biopolymeric systems (e.g., collagen, silk and chitosan) are demonstrating that the imposed electric field can orient and align the polymer chains to form hierarchically organized microstructures (e.g., collagen fibrils). In addition to using reversible mechanisms for assembly, biology also uses oxidation mechanisms to induce protein matrix crosslinking and functionalization, and these mechanisms are often residue-specific (i.e., different mechanisms are used to induce crosslinking through cysteine thiols, lysine amines and tyrosine phenols). Using biology as a model, we are developing electrochemical approaches to generate diffusible oxidants to induce hydrogel electrodeposition through covalent crosslinking mechanisms. In addition, electrochemically-induced oxidations can be used to directly graft functional moieties to hydrogels, and in some cases to “activate” hydrogels for subsequent functionalization (e.g., for the grafting of enzymes).2,3 Fabrication Examples. The best-studied example is the cathodic electrodeposition of the pH-responsive aminopolysaccharide chitosan through a neutralization mechanism (the high pH adjacent to the cathode induces chitosan’s sol-gel transition). The versatility of electrical signals is illustrated by two studies. First, when the electrical input was provided in an oscillatory fashion, a segmented hydrogel structure emerged with the segment regions controlled by the “ON” signal and the boundary regions controlled by the “OFF” signal.4 Second, when chitosan’s electrodeposition was performed in 2 steps with low salt in the first step and high salt in the second step, a Janus structure emerged with one face being dense and non-porous and the other face being highly porous.5 Conclusion. Biology provides materials and mechanisms for bottom-up assembly, while electrochemistry can provide the precisely controlled top-down cues that guide the emergence of complex structure. The simplicity and safety of electro-bio-fabrication suggests it can be adapted to a wide range of applications. The challenge is to understand the mechanistic details associated with the coupling of top-down and bottom-up “information” to enable flexible design and feedback controlled manufacturing. Cited Literature Li et al. 2019. Electrobiofabrication: Electrically-Based Fabrication with Biologically-Derived Materials. Biofabrication. 11 032002 Li, J., E. Kim, K. M. Gray, C. Conrad, C.-Y. Tsao, S. P. Wang, G. Zong, G. Scarcelli, K. M. Stroka, L.-X. Wang, W. E. Bentley, G. F. Payne. 2020. Mediated Electrochemistry to Mimic Biology’s Oxidative Assembly of Functional Matrices. Advanced Functional Materials, 30 (30), 2001776 Li, J., S.P. Wang, G. Zong, C.-Y Tsao, E. VanArsdale, L.-X Wang, W.E. Bentley, G.F. Payne. 2021. Interactive Materials for Bidirectional Redox‐Based Communication. Advanced Materials, 33 (18), 2007758. Yan et al. 2018. Electrical Programming of Soft Matter: Using Temporally Varying Electrical Inputs to Spatially Control Self Assembly. Biomacromolecules, 19, Lei et. al. 2019. Programmable Electrofabrication of Porous Janus Films with Tunable Janus Balance for Anisotropic Cell Guidance and Tissue Regeneration. Advanced Functional Materials, 1900065 Figure 1
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Williams, Rhys, Sivakkumaran Sukumaran, Qaisar Abbas, and Michael Hunt. "Few-Layer Graphene As an Electrode, Electrode Additive and an Interfacial Layer in Aqueous Supercapacitors." ECS Meeting Abstracts MA2022-02, no. 8 (October 9, 2022): 660. http://dx.doi.org/10.1149/ma2022-028660mtgabs.
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The intermittent nature of many renewable energy sources such as wind and solar, coupled with fluctuations in energy demand, creates a pressing need for efficient, low-cost energy storage technologies. Supercapacitors are promising candidates to play a role in next-generation energy storage systems. They have a higher power density and better cycle life (although lower energy density) than batteries making them ideal for rapid energy storage and deployment [1]. Activated carbon is a favoured electrode material due to high surface area, although low conductivity requires use of a conductive additive (often carbon black), reducing available surface area for charge storage. In contrast, the high conductivity and specific surface area of graphene has made it a promising material for electrochemical double layer supercapacitors (EDLCs) [2], however, performance is limited by restacking of the graphene sheets, reducing available surface area. In this work, high-shear exfoliated few layer graphene (FLG) [3] is investigated both as an electrode material and as a conductive additive/interfacial layer for EDLCs. FLG suspensions were produced under a variety of exfoliation conditions, with platelet thickness and linear dimension determined from Raman spectroscopy based on metrics developed by Backes et al. [4] and through scanning electron microscopy (SEM). The FLG suspensions were used in three ways: i) to create thin ‘graphene paper’ electrodes; ii) as a conductive additive, mixed into the activated carbon electrode material; iii) deposited onto the back of (and diffused within) activated carbon electrodes. These electrodes were investigated by Raman spectroscopy and Scanning Electron Microscopy, before being assembled into symmetric two-terminal aqueous cells then evaluated by cyclic voltammetry (CV), galvanostatic charge/discharge (GCD), and electrochemical impedance spectroscopy (EIS), and their electrochemical performance related to structure and composition. As expected, pure FLG electrodes often showed excellent low series resistance values, however specific capacitance was low, due to restacking. Directly mixing 5% FLG into activated carbon as a conventional conductive additive led to a specific capacitance of 63 F/g (from CV at 10 mV/s), and a series resistance of 19 W (from GCD at 1 A/g) - markedly inferior to those with 5% carbon black as a conductive additive (95 F/g and 2 Ohm) and inferior even to electrodes with no conductive additive (87 F/g and 10 Ohm). However, post fabrication deposition/infusion of FLG offers comparable performance to carbon black (90 F/g and 1 Ohm) at 7% FLG by weight. As the quantity of FLG is increased the specific capacitance decreases sharply. This behaviour is attributed to FLG restacking on the rear of the electrode, so adding mass whilst providing limited additional capacitance, and compression of the electrode. Adding high-shear exfoliated FLG to activated carbon electrodes shows promise for obtaining the benefits of both materials. At present, FLG/activated carbon electrodes can match the performance of those produced from activated carbon with a carbon black conductive additive and, with further optimization, we expect will be able to exceed them. Figure: a) Cross sectional SEM image of activated carbon electrode with graphene interfacial layer; b) magnified cross sectional SEM image of graphene interfacial layer; c) cyclic voltammograms at 10 mV/s of the different electrodes mentioned in the abstract. References: [1] A. Gonzalez, E. Goikolea, J.A. Barrena and R. Mysyk; ‘Review on supercapacitors: Technologies and materials’, Renewable and Sustainable Energy Reviews, 58, 1189-1206 (2016). [2] M.F. El-Kady, Y. Shao, and R.B. Kaner; ‘Graphene for batteries, supercapacitors and beyond’, Nature Reviews Materials 1, 16033 (2016). [3] K.R. Paton et al.; ‘Scalable production of large quantities of defect-free few-layer graphene by shear exfoliation in liquids’, Nature Materials, 13, 624-630 (2014). [4] C. Backes et al. ‘Spectroscopic metrics allow in-situ measurement of mean size and thickness of liquid-exfoliated graphene nanosheets’, Nanoscale 8, 4311-4323 (2016). Figure 1
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Plakhotnyuk, Maksym, Atilla C. Varga, Karolis Parfeniukas, Ivan Kundrata, and Julien Bachmann. "Inherently Selective Atomic Layer Deposition for Optical and Sensor Applications: Microreactor Direct Atomic Layer Processing (μDALP™)." ECS Meeting Abstracts MA2023-02, no. 29 (December 22, 2023): 1463. http://dx.doi.org/10.1149/ma2023-02291463mtgabs.
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In parallel to additive manufacturing leading the revolution in traditional manufacturing, the same principles can revolutionize traditional thin film deposition techniques. Where lithography and vapor phase deposition techniques struggle, for example, with rapid iterations for prototyping or incompatibility with the used chemistry, additive manufacturing can shine. Indeed, several approaches are in development for 3D nanopriting1,2,3. Atomic Layer Deposition, and in more general Atomic Layer Processing, offers a unique opportunity for localized 3D processing/printing due to its two-step process. While simple in theory, due to well-developed examples of Spatial Atomic Layer Deposition (SALD), in practice miniturization of SALD requires substantial effort into the creation of suitable micro-nozzles. Uniquely, ATLANT 3D has developed proprietary Spatial ALD micronozzles, naming the process microreactor Direct Atomic Layer Processing - µDALPTM. The µDALPTM process undergoes the same cyclic ALD process but, thanks to the in-house microreactor development, is only done in a localized area. The microreactor or micronozzle confines the flows of gases used for ALD within a µm-scale area on the substrate, wherein the reactive species adsorb on the surface to deposit one monolayer of the desired material. Similarly, to spatial ALD, the creation of this monolayer then hinges on the movement of the substrate.4 Since the µDALPTM process is based on physical separation, it is theoretically compatible with any ALD process. As such, the material capabilities can match traditional ALD and exceed other special or patterning thin film techniques, such as lithography, which can be costly and time-consuming, especially for rapid prototyping required for innovation. Films deposited with ATLANT 3D technology have been shown to produce high-quality, crystalline, atomically precise thin films.1 It has been used to fabricate temperature (Fig.1) and capacitive sensors with sensitivities that meet or exceed those of devices made using conventional vapor phase deposition techniques.5 Low-cost rapid prototyping facilitated by ATLANT 3D technology of such devices enables design innovation and optimization not possible with other thin film deposition techniques. ATLANT 3D platform provides flexibility in deposition geometry (Fig.2) that enables a range of optical applications that require high-precision fabrication techniques. Optically transparent films can be used as localized thin protective layers for device encapsulation, as well as for atomic corrections of defects. Alternating deposition materials enable multilayer mirror fabrication of custom dimensions. Smooth thickness gradients can be used to manufacture ultrathin optical lenses. Overlapping depositions with discrete steps enable the manufacturing of binary lenses and phase masks. Growth rate enhancement in rastered direct processing mode using ATLANT 3D technology can produce periodic grating structures.1 Conformal coatings on complex surfaces can act as functionalization layers or seed layers for further material deposition through e.g. electrochemical processes. [1] Kundrata I. et al., ALD/ALE 2022 [Int. Conf.], 2022 [2] de la Huerta C. A. M. et al., arXiv, 2020, 0523. [3] Winkler, R. et al., J. Appl. Phys., 2019, 125, 210901 [4] Paul Poodt., JVSTA., 2012, 30, 010802 [5] Kundrata, I. et al., Small Methods., 2022, 6 (5), 2101546 Figure 1
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Frigant, Vincent. "L’industrie 4.0, vers une dé-globalisation des chaînes de valeur ? Effets attendus de la robotique industrielle avancée et de la fabrication additive sur le système de coordination." Revue d'économie industrielle, no. 169 (September 1, 2020): 127–60. http://dx.doi.org/10.4000/rei.8828.
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Polozov, Igor, Nikolay Razumov, Dmitriy Masaylo, Alexey Silin, Yuliya Lebedeva, and Anatoly Popovich. "Erratum: Polozov, I., et al. Fabrication of Silicon Carbide Fiber-Reinforced Silicon Carbide Matrix Composites Using Binder Jetting Additive Manufacturing from Irregularly-Shaped and Spherical Powders. Materials 2020, 13, 1766." Materials 13, no. 11 (June 9, 2020): 2630. http://dx.doi.org/10.3390/ma13112630.
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Bermundo, Juan Paolo, Dianne Corsino, Umu Hanifah, and Yukiharu Uraoka. "(Invited) High Performance Fully Solution Processed Transistors Towards Flexible Sustainable Electronics." ECS Meeting Abstracts MA2022-02, no. 35 (October 9, 2022): 1279. http://dx.doi.org/10.1149/ma2022-02351279mtgabs.
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The shift towards a human-centered society promotes greater interconnectedness between people and the digital space. Modern devices such as displays and sensors in which thin-film transistors (TFT) are key materials have crucial roles in the next-generation society because displays are used as both information terminals and interface for human-device interactions while sensors gather data. Furthermore, there is growing interest in neuromorphic devices which aim to mimic the human brain’s efficiency in simultaneously processing and memorizing information to address the von Neumann bottleneck pervasive in modern computing architecture [1]. Amorphous oxide semiconductors (AOS) have gained attention as excellent materials for TFT [2], memory [3], sensing [4], and neuromorphic [5] applications for their superb combination of electrical performance and transparency. Currently, AOS devices are still mainly fabricated using vacuum process. To achieve high throughput and cost-effective production of numerous ubiquitous devices necessary in the next-generation society, an alternative fabrication process is needed. Solution process is an exceptional candidate because of its: (i) efficient production with cost-effective equipment, (ii) large material utilization (low waste) since it can be an additive process compared to vacuum process (high waste), and (iii) low temperature processability for flexible applications in healthcare, energy, and electronics. However, solution process still has major issues such as inferior performance and reliability compared with vacuum process. Several processes have been developed to address these issues but are mostly focused on improving performance and usually limited to a single solution processed device layer – the channel or gate insulator [6]. Thus, many still opt for vacuum process or a single solution processed layer as a compromise. For truly high throughput fabrication, all device layers should be fabricated by solution process. In reality, fully solution-processed TFTs are challenging to fabricate, have dismal performance (mobility (μ) < 1 cm2/Vs), and poor reliability. Therefore, high temperature (>400 °C) process and exotic materials are required for decent μ <10 cm2/Vs which precludes their use in high performance flexible device applications [7]. Here, we present how photo-assisted methods through UV treatment and excimer laser annealing (ELA) can selectively transform AOS regions at low substrate temperatures [8]. Consequently, a single AOS film acts as both the semiconductor channel and conducting electrode to realize fully solution processed TFTs with μ of ~40 cm2/Vs (see Fig. 1) [9]. We also show how alternative methods can be used to enhance the performance and stability of fully solution processed TFTs on rigid/flexible substrates. In particular, how low temperature processes such as light, plasma, and material design of functional materials enable high throughput solution processing of flexible electronic devices. Acknowledgment This research was supported by JSPS Kakenhi Grant no. 22K14291. References [1] J. von Neumann, IEEE Ann. Hist. Comput. 15, 27 (1993). [2] K. Nomura et al. Nature 432, 488–492 (2004). [3] C. H. Kim et al Appl. Phys. Lett. 97, 062109 (2010) [4] R. Jaisutti et al ACS Appl. Mater. Interfaces 8, 20192–20199 (2016) [5] M. Lee et al Adv. Mater. 29, 1700951 (2017) [6] J. W. Park et al Adv. Funct. Mater. 30, 1904632 (2020). [7] S. J. Lee et al ACS Appl. Mater. Interfaces 8, 12894 (2016) [8] J. P. Bermundo et al ACS Appl. Mater. Interfaces 10, 24590 (2018) [9] D. Corsino et al ACS Appl. Electron. Mater., 2, 2398 (2020) Figure 1
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Ahmadi, Kamyar, Peter Quaye, Nikhil Dole, Aniruddha Joi, and Stanko Brankovic. "Minimum Thickness of Continuous Cu Layers on Mo from Fluoride Free Electrolytes." ECS Meeting Abstracts MA2022-01, no. 23 (July 7, 2022): 1187. http://dx.doi.org/10.1149/ma2022-01231187mtgabs.
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Mo as a refractory metal has physical properties which are of interest for applications in CIGS photovoltaic cells fabrication and for next generation of liners for Cu interconnects[1]. Therefore it is of fundamental and practical interest to develop a process for Cu metallization of Mo surfaces where contiguity and high coverage is achieved at minimum thickness. However, one of the obstacles that prevent readily use of Mo as substrate for Cu electrodeposition is tendency of its surface to form a high quality oxide[2] ,[3].The surface energy of Mo-oxide is much lower than Cu which results in sporadic 3D nucleation and low adhesion of Cu deposit[2]. The presented work addresses this fundamental problem by combining the knowledge/breakthroughs demonstrated in the field of electro-polishing of refractory metals such as Nb[4] with common pulse electrodeposition practice[1] ,[5]. A design of deposition pulse reverse potential/current function for Cu is presented which converts a Mo-oxide/Cu to a Mo/Cu interface. Elaborate measurements of the thin film impedance during the Cu growth complemented with Pb UPD decoration studies and AFM surface morphology analysis are presented. These data indicate that Cu layers reach full contiguity and coverage of the Mo substrate at the thickness level of 3-5 nm. Considering that common Cu electrodeposition bath chemistry for interconnects contains additives whose incorporation makes Cu deposit somewhat incompatible with photovoltaic layers[1], this work presents the Cu solution chemistry which is additive free and can serve as a base for further improvement of the specific Cu deposition processes depending on its application. [1] . J. Bi et al, Journal of Power Sources, 326, (2011) 211. [2] . D. Mercier et al, Journal of the Electrochemical Society, 160 (2013) 3103. [3] . M. Pourbaix, Atlas of electrochemical equilibria in aqueous solutions. 2d English ed. 1974, Houston, Tex.: National Association of Corrosion Engineers. [4] . Journal of The Electrochemical Society, 160 (9) E94-E98 (2013). [5] . J.C. Puippe and F. Leaman, Theory and Practice of Pulse Plating, AESF, (1986).
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Surma, Mateusz, Mateusz Kaluza, Patrycja Czerwińska, Paweł Komorowski, and Agnieszka Siemion. "Neural-network based approach to optimize THz computer generated holograms." Photonics Letters of Poland 13, no. 4 (December 30, 2021): 88. http://dx.doi.org/10.4302/plp.v13i4.1124.
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Terahertz (THz) optics often encounters the problem of small f number values (elements have relatively small diameters comparing to focal lengths). The need to redirect the THz beam out of the optical axis or form particular intensity distributions resulted in the application of iterative holographic methods to design THz diffractive elements. Elements working on-axis do not encounter significant improvement while using iterative holographic methods, however, for more complicated distributions the difference becomes meaningful. Here, we propose a totally different approach to design THz holograms, utilizing a neural network based algorithm, suitable also for complicated distributions. Full Text: PDF ReferencesY. Tao, A. Fitzgerald and V. Wallace, "Non-Contact, Non-Destructive Testing in Various Industrial Sectors with Terahertz Technology", Sensors, 20(3), 712 (2020). CrossRef J. O'Hara, S. Ekin, W. Choi and I. Song, "A Perspective on Terahertz Next-Generation Wireless Communications", Technologies, 7(2), 43 (2019). CrossRef L. Yu et al., "The medical application of terahertz technology in non-invasive detection of cells and tissues: opportunities and challenges", RSC Advances, 9(17), 9354 (2019). CrossRef A. Siemion, "The Magic of Optics—An Overview of Recent Advanced Terahertz Diffractive Optical Elements", Sensors, 21(1), 100 (2020). CrossRef A. Siemion, "Terahertz Diffractive Optics—Smart Control over Radiation", J. Infrared Millim. Terahertz Waves, 40(5), 477 (2019). CrossRef M. Surma, I. Ducin, P. Zagrajek and A. Siemion, "Sub-Terahertz Computer Generated Hologram with Two Image Planes", Appl. Sci., 9(4), 659 (2019). CrossRef S. Banerji and B.Sensale-Rodriguez, "A Computational Design Framework for Efficient, Fabrication Error-Tolerant, Planar THz Diffractive Optical Elements", Sci. Rep., 9(1), 5801 (2019). CrossRef J. Sun and F. Hu, "Three-dimensional printing technologies for terahertz applications: A review", Int. J. RF. Microw. C. E., 30(1) (2020). CrossRef E. Castro-Camus, M. Koch and A. I. Hernandez-Serrano, "Additive manufacture of photonic components for the terahertz band", J. Appl. Phys., 127(21), 210901 (2020). CrossRef https://community.wolfram.com/groups/-/m/t/2028026?p_%20479%20p_auth=blBtLb5d DirectLink P. Komorowski, et al., "Three-focal-spot terahertz diffractive optical element-iterative design and neural network approach", Opt. Express, 29(7), 11243-11253 (2021) CrossRef M. Sypek, "Light propagation in the Fresnel region. New numerical approach", Opt. Commun., 116(1-3), 43 (1995). CrossRef
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Bernasconi, Roberto, Caterina Credi, Marinella Levi, and Luca Magagnin. "Self-Activating Metal-Polymer Composites for the Selective Electroless Metallization of 3D Printed Parts." ECS Meeting Abstracts MA2022-02, no. 23 (October 9, 2022): 970. http://dx.doi.org/10.1149/ma2022-0223970mtgabs.
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Nowadays, polymer based additive manufacturing (AM) is widely recognized as a powerful technology for the fabrication of complex three-dimensional objects of virtually any shape in a time, material, and cost effective way. Thanks to their characteristic advantages over conventional manufacturing strategies, AM technologies are the subject of relevant research efforts. In particular, great attention is placed on developing novel 3D printable materials characterized by improved properties and, among all, by novel functionalities, such as magnetic [1] and conductive properties [2]. In order to do this, the most common strategy relies on doping polymeric matrices with nanoparticles, obtaining thus functional 3D printable polymeric composites. Metal containing composites, in particular, can be exploited for their magnetic properties or for their mechanical behavior but also for their potential capability to trigger electroless deposition. It is well-known that electroless plating requires the presence of a catalytic surface, which can be constituted by the metallic particles embedded in the 3D printed composite. In this way, the need to activate the surface of non-conductive polymeric 3D printed parts can be avoided [3]. In addition, metallization can be carried out selectively by fabricating parts in a multi-material printing process [4] with both metal loaded and non-loaded materials. Since only the layers that contain the particles can metallize, conductive regions can be alternated with insulating zones to create metallic functional patterns on the surface of printed parts. This approach can enable the 3D printing of selectively self-metallizing parts, with possible applicability in the production of flexible and highly tridimensional electronic circuits, radiofrequency devices, microelectromechanical systems or microfluidic setups. The present work focuses on the development of a stereolithography (SLA) printable composite based on an acrylate resin loaded with nickel microparticles and its application as self-catalytic material for electroless metallization. This approach, unprecedented for SLA resins, eliminates the need of noble metal activation of the surface. Moreover, the usage of Ni is of great interest also due to the other properties that it can potentially impart to the printed parts: improved mechanical properties, high thermal conductivity, magnetizability. The SLA printability of the metal-loaded resin is assessed and the morphological properties of the 3D printed composites are investigated. Subsequently, the functional properties of the composites are determined, placing a particular emphasis on their capability to trigger NiP and Cu electroless deposition. Finally, the possibility to selectively metallize only specific areas is successfully demonstrated by metallizing a Ni-loaded pattern printed on a Ni-free base. [1] Huber et al.; Appl. Phys. Lett. 109, 162401 (2016) [2] Postiglione et al.; Compos. Part A Appl. Sci. Manuf. 76, 110-114 (2015) [3] Bernasconi et al.; J. Electrochem. Soc. 164, B3059–B3066 (2017) [4] Choi et al.; J. Mater. Process. Technol. 211, 318–328 (2011)
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Das, Prodip. "(Invited, Digital Presentation) Tuning Gas-Diffusion-Layer Surface Wettability for Polymer Electrolyte Fuel Cells." ECS Meeting Abstracts MA2022-01, no. 38 (July 7, 2022): 1709. http://dx.doi.org/10.1149/ma2022-01381709mtgabs.
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In the present scenario of a global initiative toward securing global net-zero by mid-century and keeping 1.5 degrees within reach, polymer-electrolyte fuel cells (PEFCs) are considered to play an important role in the energy transition, particularly for the decarbonization of transit buses, trucks, rail transport, ships and ferries, and the residential heating sector. However, PEFCs are not economically competitive with the internal combustion engine powertrains [1]. Moreover, their durability standards in widely varying conditions have yet to be established and water management remains a critical issue for performance degradation and durability [1-3]. Thus, the mission of my research team is to conduct original research to make PEFCs economically viable and optimize their performance and durability [4,5]. In this talk, I will highlight our research on PEFC’s gas diffusion layer (GDL), as its interfaces with the flow channel and microporous layer play a significant role in water management. This research was aimed at selectively modifying GDL surfaces with a hydrophobic pattern to improve water transport and water removal from flow channels; thus, improving the durability and performance of PEFCs. Sigracet® GDLs were used as a base substrate and two different monomers, polydimethylsiloxane (PDMS) added with fumed silica (Si) and fluorinated ethylene propylene (FEP) were used to print a selective pattern on the GDL surfaces [6]. Both the additive manufacturing and spray coating techniques were utilized for creating the hydrophobic pattern on the GDL surfaces. The results of this study demonstrated a novel but simple approach to tune GDL surfaces with selective wetting properties and superhydrophobic interfaces that would enhance water transport. I will discuss some of these results and highlight how these results will benefit the water management of next-generation high-power PEFCs. This work was funded by the Engineering and Physical Sciences Research Council (EP/P03098X/1) and the STFC Batteries Network (ST/R006873/1) and was supported by SGL Carbon SE (www.sglcarbon.com). References [1] A.Z. Weber et al., "A critical review of modeling transport phenomena in polymer electrolyte fuel cells," J. Electrochem. Soc., vol. 161, pp. F1254-F1299, 2014. [2] A.D. Santamaria et al., "Liquid-water interactions with gas-diffusion layers surfaces," J. Electrochem. Soc., vol. 161, pp. F1184-F1193, 2014. [3] P.K. Das and A.Z. Weber, "Water management in PEMFC with ultra-thin catalyst-layers," ASME 11th Fuel Cell Science, Engineering and Technology Conference, Paper No. FuelCell2013-18010, pp. V001T01A002, 2013. [4] L. Xing et al., "Membrane electrode assemblies for PEM fuel cells: A review of functional graded design and optimization," Energy, vol. 177, pp. 445-464, 2019. [5] L. Xing et al., "Inhomogeneous distribution of platinum and ionomer in the porous cathode to maximize the performance of a PEM fuel cell," AIChE J., vol. 63, pp. 4895-4910, 2017. [6] D. Thumbarathy et al., "Fabrication and characterization of tuneable flow-channel/gas-diffusion-layer interface for polymer electrolyte fuel cells," J. Electrochem. Energy Convers. Storage, vol. 17, pp. 011010, 2020.
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Valero, Anthony, Julien Barbe, Emanuele Barborini, and Guillaume Lamblin. "Development and Testing of Innovative Carbon Nanotubes/ Copper Composite Foils, Towards Lighter and Mechanically Improved Anode Current Collector for Lithium-Ion Batteries." ECS Meeting Abstracts MA2023-02, no. 9 (December 22, 2023): 1002. http://dx.doi.org/10.1149/ma2023-0291002mtgabs.
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Up to now, copper is an essential material for lithium-ion battery industry as preferential candidate for anode current collectors due to its high conductivity, low price, and electrochemical stability in the working potential range of the anodic electroactive material. However, such component, accounting for 8.1% of the battery total weight, does not participate in any energy storage processes. [1] Thus, the trend is in this industry is to decrease the weight as well as the thickness of the collector foil to optimize the gravimetric energy of the whole lithium-ion battery system. It is therefore of interest to explore the development of lighter current collectors with equal/improved mechanical and electrical properties. Nanocarbon materials such as Multi-Wall Carbon Nanotubes (MWCNTs) and Single-Wall Carbon Nanotubes (SWCNTs) display a combination of performances, namely high electrical conductivity, low density and high mechanical stability, of a high interests to be combined with copper as innovative lightweight current collectors. Such nanocarbon/copper composite represents a valid alternative to foster the rapid change the battery technology is undergoing. In 2013, Subramaniam et al. [2] reported the fabrication of a Copper /Carbon nanotubes (Cu-CNTs) composites with a similar specific conductivity than that of copper and an ampacity increased by two orders of magnitude. Moreover, Arai et al. have shown, by Electrochemical impedance analysis, that MWCNTs additive in a copper matrix can serve as preferential electron conduction pathway inside a Lithium-ion battery anode. [3] Recently, a new promising and scalable way to fabricate nanocarbon/copper composite has been demonstrated by our team. The process involved the coating of MWCNTs by a dispersing agent, namely the Polydopamine biopolymer, their spraying, and finally the electrochemical plating of metallic copper inside the porosity of the MWCNTs network.[4] Following similar approach, the present work exhibits the fabrication of a free standing MWCNTs/ Copper composite current collector foil of a thickness of 9 µm, a value reaching the industrial standards required by the Lithium-ion battery market players for the next generation cells.[5] Scanning Electron Microscopy and Transmission Microscopy have been used to investigate the interaction between the copper matrix and the carbonaceous reinforcement additive. Figure 1. displays a cross section of nanocarbon/copper composite obtain via Focused Ion Beam slicing, where homogeneous mixing of copper and carbon phases down to nanoscale is highlighted. Such experiments contribute to the understanding of the copper nucleation mode on modified MWCNTs which remains insufficiently controlled to this day. Nanoindentation technique and electromechanical tensile testing bench were combined to study the mechanical properties of such material to be used under mechanical stress as battery collector. In contrary to conventional indentation technique where the mechanical properties of micro-size area are probed, indentation at nanoscale allow the probing of the local mechanical heterogeneity of a composite material. Using such technique, the fabricated self-standing nanocarbon/copper composite was shown to display average hardness and Young modulus close to those of pure carbon (3.5 GPa and 152 GPa respectively). Electrochemical performances of the composite as anode battery collector are under test into pouch and coin-cells battery architecture. The adhesion strength between the electrode slurry and the nanocomposite substrate material is expected to be reinforced by the addition of a nanocarbon. A focus was made on the impact of the use of this new collector material on the cycling stability of typical Lithium-ion battery commercial mixture. Preliminary results indicate that the Cu/MWCNT composite is a promising current collector material to withstand the expansion/contraction imposed by the working cycles of a rechargeable Lithium-ion battery. [1] Zhu, P. Gastol, D. Marshall, J. Sommerville, R. Goodship, V. Kendrick, E. J Power Sources, 485, 229321 (2021) [2] Subramaniam, C. Yamada, T. Kobashi, K. Sekiguchi, A. Futaba, Yumura, D. N. Hata, K. Nat Commun,4, 2202 (2013). [3] Shimizu, M. Ohnuki, T. Ogasawara, T. Banno, Arai, S., RSC Advances, 9(38), 21939-21945 (2019) [4] Duhain, A. Guillot, J. Lamblin, G. Lenoble, D., RSC Advances,11(63), 40159-40172 (2020) [5] Copper Foil Market, Straits Research, 9.5.2.3.(2022) Figure 1. Scanning Electron Microscopy imaging of the cross section of MWCNTs/Copper composite with a thickness lower than 3 µm – 7kV acceleration, 45° tilt. . Figure 1
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Lepengue, Alexis Nicaise, Aurélien Mokea-Niaty, Davy U. Ikabanga, Roland Lingombe, Dhert Souviens Tshi-Tshi Ontod, Ephrem Nzengue, Stéphane Mombo, Jean Fabrice Yala, Alain Souza, and Bertrand Mbatchi. "Effet de Garcinia kola (Clusiaceae) dans les processus de fermentation du vin de canne à sucre (Saccharum officinarum; Poaceae) au Gabon." International Journal of Biological and Chemical Sciences 14, no. 3 (June 19, 2020): 1074–84. http://dx.doi.org/10.4314/ijbcs.v14i3.33.
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Le nectar de canne à sucre (Saccharum officinarum L.) est utilisé au Gabon non seulement pour la fabrication du sucre industriel, mais également pour la synthèse traditionnelle de vins locaux appelés ‘‘Musungu’’ ou ‘‘Malamba’’. Ces synthèses alcooliques nécessitent l’emploi de nombreux adjuvants dont le rôle exact reste mal défini. Le présent travail a été initié pour étudier l’un d’eux, le bois amer (Garcinia kola) utilisé dans diverses synthèses alcooliques. La méthodologie a consisté à analyser l’évolution de certaines qualités physicochimiques et biochimiques de 1 l des nectars de canne à sucre seuls (témoin), associés à la lie d’anciens vins de canne (Li), au bois amer (Gk) ou à ces 2 amendements (LG), avant et après 4 semaines de fermentation. Les résultats obtenus ont révélé la baisse de l’acidité, de la densité et des sucres totaux dans tous les traitements essais, contrairement aux témoins, après les 28 jours d’incubation. Tous les traitements (essais et témoins) ont en revanche produit des alcools de fortes teneurs comprises entre 7,4 °GL et 9,9 °GL. Mais les vins des traitements témoins quoique très alcoolisés ont tous été jugés aigres et de très mauvaise qualité gustative. Le bois amer ne paraît donc pas intervenir dans les processus de fermentation alcoolique, mais dans la constitution des qualités organoleptiques, en empêchant la prolifération des germes lactiques. Ainsi, dans la perspective d’optimiser la qualité du vin, identifier les germes participants à la fermentation du nectar de canne, sous l’influence de Garcia kola semble être nécessaire.Mots clés : Nectar, Levures, Adjuvants, Alcool, Qualité organoleptique.
English Title: Effect of Garcinia kola (Clusiaceae) in the fermentation processes of sugar cane wine (<i>Saccharum officinarum</i> ; Poaceae) in Gabon
Sugarcane nectar (Saccharum officinarum L.) is used in Gabon not only for the production of industrial sugar, but also for the traditional synthesis of local wines called ''Musungu'' or ''Malamba''. These alcoholic syntheses require the use of many adjuvants whose exact role remains poorly defined. The present work was undertaken to study one of them, the bitter wood (Garcinia kola) used in various alcoholic syntheses. The methodology consisted of analyzing the evolution of certain of physicochemical and biochemical qualities of 1 l of sugar cane nectars alone (control), associated with the lees of old cane wines (Li), bitter wood (Gk) or 2 amendments (LG), before and after 4 weeks of fermentation. The results obtained revealed the decrease of the acidity, the density and the total sugars in all the treatments tests, contrary to the controls, after the 28 days of incubation. On the other hand, all the treatments (tests and controls) produced alcohols with high contents of between 7.4 °GL and 9.9 °GL. But the wines of the control treatments, although very alcoholic, have all been judged as sour and of very poor taste quality. Bitter wood therefore does not appear to be involved in the processes of alcoholic fermentation, but in the constitution of organoleptic qualities, by preventing the proliferation of lactic acid bacteria. Thus, in order to optimize the quality of the wine, identifying the germs involved in the fermentation of cane nectar, under the influence of Garcia kola seems to be necessary.Keywords: Nectar, Yeasts, Additive, Alcohol, Organoleptic quality.
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Martinez Maciel, Ana C., Alexis Maurel, Eva Schiaffino, Ana Aranzola, Cameroun Sherrard, and Eric MacDonald. "3D Printing of Gel Polymer Electrolytes for Sodium-Ion Batteries." ECS Meeting Abstracts MA2023-01, no. 1 (August 28, 2023): 410. http://dx.doi.org/10.1149/ma2023-011410mtgabs.
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In order to maximize the capabilities of existing battery chemistries, a big effort has been recently focused on manufacturing more complex battery structures, which promotes 3D lithium ion diffusion resulting in an increase in power density.1-3 The current limitation is still the manufacturing part, which is often complex and expensive for mainstream production. 3D printing appears in this context as an exceptional tool to fill the gaps for 3D battery manufacturing. Among the 3D printing processes, vat photopolymerization is especially interesting thanks to its high printing resolution through a layer-by-layer curing approach that solidifies a UV-photocurable resin. Multiple examples of functional 3D printed batteries manufactured by various methods have been reported in the literature.4-7 Most of the recent works have been focused on half-cells where only one electrode is printed, or complete cells containing printed electrodes but using a non-printed conventional separator-electrolyte couple in between. Among the alternatives to replace this couple for a functional and printable material, gel polymer electrolytes appear as an appropriate option because they possess the advantages of a liquid electrolyte, without severely compromising the mechanical integrity. In addition, they exhibit competitive ionic conductivity and enhanced safety in comparison to liquid electrolytes, and they do not require a thermal post-processing step to be manufactured. Combining the knowledge in this topic with the design freedom that 3D printing allows will certainly contribute to obtaining the next generation of 3D printed batteries. In a first instance, this work will show a brief overview about suitable UV-photocurable resin compositions that can be employed as gel polymer electrolytes in sodium-ion batteries, with a view to employ them as material feedstock in the high-resolution vat photopolymerization process. The freedom of design that 3D printing allows will be then shown through a variety of printed items that transcend the well-known tape casting method to produce conventional gel polymer electrolytes. Finally, a variety of electrochemical tests to prove stability, ionic conductivity and performance within sodium-ion batteries will be shown. Talin, A. A. et al. Fabrication, Testing, and Simulation of All-Solid-State Three-Dimensional Li-Ion Batteries. ACS Appl. Mater. Interfaces 8, 32385–32391 (2016). Liu, Y. et al. Transforming from planar to three-dimensional lithium with flowable interphase for solid lithium metal batteries. Sci Adv 3, eaao0713 (2017). Long, J. W., Dunn, B., Rolison, D. R. & White, H. S. 3D architectures for batteries and electrodes. Adv. Energy Mater. 10, 2002457 (2020). Cheng, M., Deivanayagam, R. & Shahbazian-Yassar, R. 3D printing of electrochemical energy storage devices: A review of printing techniques and electrode/electrolyte architectures. Batter. supercaps 3, 130–146 (2020). Pang, Y. et al. Additive manufacturing of batteries. Adv. Funct. Mater. 30, 1906244 (2020). Zeng, L. et al. Recent progresses of 3D printing technologies for structural energy storage devices. Materials Today Nano 12, 100094 (2020). Maurel, A. et al. Toward High Resolution 3D Printing of Shape-Conformable Batteries via Vat Photopolymerization: Review and Perspective. IEEE Access 9, 140654–140666 (2021).
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Patra, Arghya, and Paul V. Braun. "(Industrial Electrochemistry and Electrochemical Engineering Division H. H. Dow Memorial Student Achievement Award) Electrochemically Grown Highly Textured Thick Ceramic Oxide Films for Energy Storage: A New Manufacturing Paradigm for Cathode Materials." ECS Meeting Abstracts MA2022-02, no. 26 (October 9, 2022): 1025. http://dx.doi.org/10.1149/ma2022-02261025mtgabs.
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Electrochemical synthesis of materials has contributed to significant breakthroughs in materials processing by replacing high temperature, cost and energy intensive pyrometallurgical processes. Noteworthy examples include aluminum extraction by Hall–Heroult process, electrowinning of copper, titanium extraction through the Kroll process, electrolytic production of steel, and electrochemical synthesis of cement. Increasing the energy and power density of alkali ion intercalated transition metal oxide cathodes which power electric cars and portable electronics, has been a growing topic of global techno-economic interest. Our work demonstrates a direct electrodeposition of thick ternary ceramic oxide films as an alternate scalable manufacturing technique for fabrication of binder-and-additive free cathode materials for secondary battery. Employing an intermediate temperature (200-400°C) molten hydroxide-based electrodeposition method, a general electrochemical growth strategy for multiple Li and Na ion cathode chemistries is demonstrated for the first time including NaCoO2, NaMnO2, LiCoO2, Li2MnO3, LiMnO2, LiMn2O4, (A. Patra, P.V. Braun et. al, PNAS, 2021) in a thick (> 50 µm) thick film form factor. In-plane and through-plane texture can be electrochemically architectured in LiCoO2 and NaCoO2 films across multiple textures: <003>||ND (Li/Na ion blocking sites parallel to the normal direction), <101>||ND, <104>||ND, <110>||ND (fast lithium ion conducting sites parallel to the normal direction). An accurate control of crystallization dynamics leads to highly anisotropic, grain boundary engineered structure with low tortuosity and fastest electron and Li ion conducting pathways (<110>||ND) oriented normal to the current collector. The highly textured (<110>||ND), dense (>95%) electroplated cathodes can perform even at ultrahigh thickness of ~ 200 µm (areal capacity of ~13.6 mAh/cm2) in comparison to 40-60 µm for conventional slurry cast cathodes (areal capacity of ~3-4 mAh/cm2 with a porosity of ~10-20%), a fivefold increase in areal capacity and volumetric energy density (A. Patra, P.V. Braun et. al, to be submitted). In order to enable a high voltage (> 4.5 V vs. Li) cathode design, a functionally graded architecture is also demonstrated with a core capable of providing high-capacity and rate capability (LCO <110>||ND); and multiple capping layers (LCO <003>||ND and Li2MnO3) to suppress harmful side reactions occurring at voltages beyond the normal operation range (beyond 4.2 V vs. Li). Our work paves the way towards an electrosynthesis platform for functional oxides with the ability to generate micron scale ordering with controllable in-and-through-plane orientation in thick ceramic oxide films important for electrochemical energy storage.
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Song, Yunha, Jinhyun Lee, Youjung Kim, Jinmyeong Seo, Inseong Hwang, Sanghwa Yoon, and Bongyoung Yoo. "Localized Electrochemical Deposition Using Copper Pyrophosphate-Based Electrolyte." ECS Meeting Abstracts MA2023-02, no. 20 (December 22, 2023): 1276. http://dx.doi.org/10.1149/ma2023-02201276mtgabs.
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Additive manufacturing (AM) has gained popularity across various industries due to its cost-effectiveness, low material consumption, and minimal environmental impact. Localized electrochemical deposition (LECD), as one of the AM methods, has the capability to produce microcomponents or structures at an microscale in a specific position as designed, without the need for any mask or support material[1]. By reducing copper ions in the local area according to the position of the micro-wire, 3D structures could be produced. This electrochemical deposition process has a significant advantage in that it is a low-temperature process and has lower costs compared to other processes[2]. Using the LECD process, the micrometer of copper columns was conventionally deposited in copper sulfate-based electrolyte[3]. However, this electrolyte has the possibility to cause damage to the metal substrate used as the cathode due to its low pH, resulting in metal dissolution. The utilization of copper pyrophosphate-based electrolyte, which is a solution with a pH close to neutral, can solve this problem. Also, copper pyrophosphate-based electrolyte offers an advantage over conventional alkaline-based electrolytes in that it removes cyanide pollution of the environment and hazards to human health.[4] In this study, the microanode was employed using a platinum wire(100 μm in diameter), while a copper substrate was employed as the cathode in the electrochemical deposition process. The micrometer copper columns were deposited using copper pyrophosphate-based electrolyte by varying the main electrochemical deposition factors, such as applied potential and pulse duty cycle. In addition The surface morphology of the deposited micrometer-scale copper columns was observed through scanning electron microscopy. REFERENCES [1] Suryavanshi, Abhijit P., and Min-Feng Yu. "Probe-based electrochemical fabrication of freestanding Cu nanowire array." Applied Physics Letters 88.8 (2006): 083103. [2] Madden, John D., and Ian W. Hunter. "Three-dimensional microfabrication by localized electrochemical deposition." Journal of microelectromechanical systems 5.1 (1996): 24-32. [3] Lin, J. C., et al. "Localized electrochemical deposition of micrometer copper columns by pulse plating." Electrochimica Acta 55.6 (2010): 1888-1894. [4] Chen, C-C. "A New Process for Cyanide-Free Copper Plating."Electroplating and Pollution Control 23.4 (2003): 10-11.
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Bain, Aaron Thomas, Rory Roberts, Jay Deiner, and Joseph Fellner. "Computational Optimization of Functionally Graded Electrodes for Solid Oxide Fuel Cells." ECS Meeting Abstracts MA2022-02, no. 47 (October 9, 2022): 1794. http://dx.doi.org/10.1149/ma2022-02471794mtgabs.
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Solid Oxide Fuel Cells (SOFCs) are widely considered to be an ideal power source across a range of industries in the near future due to their high efficiency, high power density, and fuel flexibility. However, for widespread usage of SOFCs to be feasible, certain disadvantages, such as their high operating temperature, electrochemical losses, and high cost of manufacturing, must be solved. In particular, the field of materials research occupies a unique position of being able to quickly and simultaneously solve many of these issues through the development of material compositions and structures that do not currently exist in the industry. Especially relevant to solid oxide fuel cells in particular, is the impact that the electrodes’ geometries and compositions have on the operating performance. The electrodes’ ability to quickly move reactants to the interface of the electrolyte and remove products to the bulk flow comes into play as the fuel cell operates at higher current densities and concentration losses become prominent. Therefore, the microstructures present throughout the electrodes’ depth plays a vital role in improving overall cell performance. However, current fuel cell research has not yet effectively captured and defined the connections of the microstructure parameters and measured their impact on cell behavior. Additionally, homogeneous electrode design and implementation have dominated the research and commercial space thus far. The technique of functional material grading, which has begun to see wide research and commercial usage for such problems as acoustic impedance matching, thermal control, and mechanical design will be leveraged for the enhancement of SOFC electrodes. Functionally graded electrodes have been used in solid oxide fuel cell research in recent years in an effort to improve the cell performance by altering the microstructure including porosity, particle size, and composition of electronic and ionic conductors near the triple phase boundary region. Normally the functional grading process adds additional fabrication steps making it less desirable as an optimization process and easy manufacturing method. However, by using an additive manufacturing process it eliminates the need for multiple discrete graded layers to be deposited to obtain a graded electrode functional layer. This study seeks to explore the correlations of geometry and structure parameters from the meso-scale through to the micro-scale level, together with mass transfer, ionic and electronic transport, and gas-surface electrochemical reactions inside the electrodes to guide future additive manufacturing of SOFCs. Outlined is the development of an effective medium model for simulating the performance of fuel cell microstructures as a function of specific operating ranges in temperature, pressure, and in fuels used. Smooth and continuous linear and nonlinear functional gradation profiles of porosity and material composition are studied within the framework of an effective medium boundary value problem where the electrochemical relations, such as the Butler-Volmer equation, percolating conduction paths, and gas diffusion are solved using the finite difference method. The form of these relations for homogeneous electrodes was analyzed by Costamagna, et. al [1], who also defined outstanding problems with regards to optimizing SOFC electrodes [2]. Globally optimal linear and nonlinear gradation profiles and cell parameters are derived as a function of particle sizes, ratio of conductivities, and desired operating conditions and scored based on their reduction of cell overpotentials. [1] Costamagna, P., P. Costa, and V. Antonucci, Micro-modelling of solid oxide fuel cell electrodes. Electrochimica Acta, 1998. 43(3-4), pp.375-394. [2] Costamagna, P., P. Costa, and E. Arato, Some more considerations on the optimization of cermet solid oxide fuel cell electrodes. Electrochimica Acta, 1998. 43(8), pp.967-972. Figure 1
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Silva, Bárbara Sousa da, Thaysa Cristina Batista de Mattos, Erika Akiko Moura Shiota, Sybilla Torres Dias, Cristiane Maria Brasil Leal, and Brigitte Nichthauser. "Reabilitação facial por meio de prótese oculopalpebral." ARCHIVES OF HEALTH INVESTIGATION 9, no. 6 (October 14, 2020): 563–69. http://dx.doi.org/10.21270/archi.v9i6.5093.
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A prótese bucomaxilofacial visa a reabilitação de pacientes que sofreram mutilações na face, restituindo estética e autoestima. Este trabalho visa relatar o caso clínico de um paciente reabilitado com prótese oculopalpebral após sofrer exenteração de órbita, decorrente de um carcinoma espinocelular em pálpebra inferior direita. Paciente, gênero masculino, 56 anos, procurou atendimento odontológico queixando-se de desconforto estético do rosto. Ao exame clínico foi observada ausência do globo ocular, pálpebras e arco superciliar do lado direito, por isto, foi planejada a confecção de uma prótese oculopalpebral. Foi realizada moldagem dos terços superior e médio da face, obteve-se o molde em alginato e, posteriormente, o modelo em gesso. Em seguida, foi confeccionado um globo ocular caracterizado em resina acrílica termopolimerizável. Posteriormente realizou-se, sobre o modelo de gesso, a escultura da área amputada utilizando-se plastilina e cera e após prova e ajustes no paciente, inclusão do conjunto modelo/escultura em mufla e contramufla, com posterior eliminação da peça esculpida. Foi selecionada a cor da pele do paciente e misturou-se uma base ao silicone, que foi incluído na mufla para prensagem. Após a vulcanização do silicone, foram realizados os acabamentos, caracterização e instalação da prótese. Na proservação o paciente relatou grande satisfação com a reconstituição da estética facial. Conclui-se que a prótese bucomaxilofacial é uma alternativa satisfatória para a reabilitação de pacientes que sofreram mutilações faciais, pois restabelece a estética facial, autoestima e convívio social.
Descritores: Prótese Maxilofacial; Olho Artificial; Reabilitação; Carcinoma de Células Escamosas.
Referências
Duncan BGF, Calhoun ME. Facial prostheses in the rehabilitation of burn patients. Nurse Life Care Planner. 2015;15(3):900-5.
Vieira LM, Oguro P, Dias RB, Pimentel ML, Barretto MRP, Coto NP. Proposition of integrated electrical mechanism anda facial prosthesis for eyelid motion on prosthetic oculopalpebral rehabilitation: technical note. J. 2019; 35(2):659-65.
Moss OB, Pinheiro BCL, Mendes TCC, Braga FP, Nichthauser B, Leal CMB. Reabilitação oral com prótese bucomaxilofacial em paciente pediátrica submetida à excisão de lesão neoplásica benigna em maxila. Arch Health Invest. 2019;8(11):706-10.
Petsuksiri J, Frank SJ, Garden AS, Ang KK, Morrison WH, Chao KS, Rosenthal DI, Schwartz DL, Ahamad A, Esmaeli B. Outcomes after radiotherapy for squamous cell carcinoma of the eyelid. 2008;112(1):111-18.
Dib LL, Oliveira JAP. Reabilitação Bucomaxilofacial - uso de próteses e implantes osseointegrados. In: Cardoso RJA, Gonçalves EAN. Odontologia: arte, ciência e técnica. 6 ed. São Paulo: Artes Médicas; 2002.
Pinheiro BCL, De Mattos TCB, Dias ST, Braga FP, Leal CMB, Nichthauser B. Reabilitação com prótese ocular em paciente anoftálmico. Full Dent. Sci. 2020;11(42):98-103.
Wondergem M, Lieben G, Bouman S, van den Brekel MW, Lohuis PJ. Patients' satisfaction with facial prostheses. Br J Oral Maxillofac Surg. 2016;54(4):394-9.
Lanzara R, Thakur A, Viswambaran M, Khattak A. Fabrication of ocular prosthesis with a digital customization technique - a case report. J Family Med Prim Care. 2019;8(3):1239-42.
Brandão TB, Filho AJV, Batista VES, Ribeiro ACP, Nary Filho H, Chilvarquer I, et al. Assessment of treatment outcomes for facial prostheses in patients with craniofacial defects: A pilot retrospective study. J Prosthet Dent. 2017;118(2):235-41.
Koyama S, Sasaki K, Hanawa S, Sato N. The potential of cohesive silicone for facial prosthetic use: a material property study and a clinical report. J Prosthodont. 2011;20(4):299-304.
Soares LHS, Bello CV, Reis AKL, Nunes RR, Mason EM. Tumores malignos de pálpebra. Arq Bras Oftalmol. 2001;64(1):287-9.
Grant GT, Aita-Holmes C, Liacouras P, Garnes J, Wilson WO Jr. Digital capture, design, and manufacturing of a facial prosthesis: Clinical report on a pediatric patient. J Prosthet Dent. 2015;114(1):138-41.
Sohaib A, Amano K, Xiao K, Yates JM, Whitford C, Werger S. Colour quality of facial prostheses in additive manufacturing. Int J Adv Manuf Technol. 2018; 96(2):881-94.
Veerareddy C, Nair KC, Reddy R. Simplified Technique for Orbital Prosthesis fabrication: a case report. J Prosthodont. 2012;21(1):561-68.
Bellamy K, Limbert G, Waters MG, Middleton J. An elastomeric material for facial prostheses: synthesis, experimental and numerical testing aspects. 2003;24(27):5061-66.
Papaspyrou G, Yildiz C, Bozzato V, Bohr C, Schneider M, Hecker D, Schick B, Al Kadah B. Prosthetic supply of facial defects: long-term experience and retrospective analysis on 99 patients. Eur Arch Otorhinolaryngol. 2018;275(2):607-13.
Chang TL, Garrett N, Roumanas E, Beumer J 3rd. Treatment satisfaction with facial prostheses. J Prosthet Dent. 2005;94(3):275-80.
Nomura T, Sato J, Matsuura M, Kawaguchi K, Sekiguchi R, Horie A, Seto K. Lightweight acrylic resin facial prosthesis for maxillofacial defects: a fabrication and retention method. J Prosthet Dent. 2013;110(4):326-30.
Dings JPJ, Merkx MAW, de Clonie Maclennan-Naphausen MTP, van de Pol P, Maal TJJ, Meijer GJ. Maxillofacial prosthetic rehabilitation: A survey on the quality of life. J Prosthet Dent. 2018;120(5):780-86.
Ariani N, Visser A, Teulings MR, Dijk M, Rahardjo TB, Vissink A, van der Mei HC. Efficacy of cleansing agents in killing microorganisms in mixed species biofilms present on silicone facial prostheses--an in vitro study. Clin Oral Investig. 2015;19(9):2285-93.
Goiato MC, Pesqueira AA, dos Santos DM, Zavanelli AC, Ribeiro Pdo P. Color stability comparison of silicone facial prostheses following disinfection. J Prosthodont. 2009;18(3):242-44.
Jebreil K. Accetability of orbital prostheses. J Prosthet Dent. 1980;43(1):82-5.
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Poetke, Stephanie, Sahin Cangaz, Felix Hippauf, Stefan Haufe, Susanne Dörfler, Holger Althues, and Stefan Kaskel. "Enhancing the Cycle Life of Solid-State Batteries by Restraining the Volume Change of Silicon Anodes." ECS Meeting Abstracts MA2023-01, no. 6 (August 28, 2023): 966. http://dx.doi.org/10.1149/ma2023-016966mtgabs.
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The high gravimetric and volumetric capacity of silicon makes it an attractive anode material for lithium-ion solid-state batteries (SSBs). [1,2] However, silicon suffers from high volume changes during cycling and requires high stack pressures to stabilize the interfaces. [3-5] Herein, we present different approaches to minimize the breathing of silicon-based anodes leading to stabilized cycling. Silicon carbon void structures (Si-C) obtain a void between the silicon nanoparticle and the surrounding carbon matrix to compensate the volume changes already within the anode structure. As a result, excellent cycling performance in solid-state cells with areal loadings as high as 7.4 mAh cm-2 can be demonstrated. Thereby, Si-C composite electrodes show higher lithiation capacities, better rate stability and higher capacity retentions than pristine silicon nanoparticles (SiNPs), which rapidly degrade due to the immense mechanical stress upon charging and discharging. Hence, the volume changes of the SiNPs are well compensated by the carbon matrix, which also stabilizes the entire electrode. In full cells with nickel-rich NCM (LiNi0.9Co0.05Mn0.05O2, 210 mAh g-1) as cathode, higher initial discharge capacities and coulombic efficiencies (72.7 % vs. 31.0 %) can be achieved compared to the liquid system. The solid electrolyte (Li6PS5Cl, 3 mS cm-1) does not penetrate the whole carbon matrix of the Si-C particles resulting in less side reactions. Consequently, prelithiation of the Si-C anodes is not required in SSBs. By applying either a low (1.1) or rather high n/p ratio (2.0) capacity retentions of up to 87.7 % after 50 cycles can be reached. [6] Especially for industrial fabrication of SSB anodes other procedures than the complex multi-step synthesis of e.g. Si-C composites are needed. [7] Consequently, we evaluated low-cost silicon microparticles (µm-Si) as partially lithiated electrode material (800 mAh g-1) in SSB half- and full cells. By reducing the utilized fraction of silicon, the breathing during cycling is reduced from 300 % to 66 %, which reduces the armorphization of the active material. In addition, the grain boundaries of silicon are connected by a matrix of solid electrolyte and carbon additive, which drastically reduces the need for a high stack pressure. After limiting the charge cut-off potential of NCM|SE|µm-Si full cells, significant increased capacity retentions from 32 % to 71 % after 50 cycles can be reached. In addition, similar performance compared to the Si-C electrodes can be demonstrated making it to an auspicious alternative. [8] Overall, the herein presented silicon materials achieved decent electrochemical performance without active pressure control on the cells being beneficial for electric vehicle and other applications. Hence, both Si-C and µm-Si particles are promising concepts for stable, high-capacity SSB anodes. Literature: [1] A. Mukanova, A. Jetybayeva, S.-T. Myung, S.-S. Kim, Z. Bakenov, Mater. Today Energy 2018, 9, 49. [2] N. Nitta, G. Yushin, Part. Part. Syst. Charact. 2014, 31, 317. [3] X. Su, Q. Wu, J. Li, X. Xiao, A. Lott, W. Lu, B. W. Sheldon, J. Wu, Adv. Energy Mater. 2014, 4, 1300882. [4] D. H. S. Tan, Y.-T. Chen, H. Yang, W. Bao, B. Sreenarayanan, J.-M. Doux, W. Li, B. Lu, S.-Y. Ham, B. Sayahpour et al., Science (N.Y.) 2021, 373, 1494. [5] S. Cangaz, F. Hippauf, F. S. Reuter, S. Doerfler, T. Abendroth, H. Althues, S. Kaskel, Adv. Energy Mater. 2020, 3, 2001320. [6] S. Poetke, F. Hippauf, A. Baasner, S. Dörfler, H. Althues, S. Kaskel, Batteries Supercaps 2021, 4, 1323. [7] D. Jantke, R. Bernhard, E. Hanelt, T. Buhrmester, J. Pfeiffer, S. Haufe, J. Electrochem. Soc. 2019, 166, A3881. [8] S. Poetke, S. Cangaz, F. Hippauf, S. Haufe, S. Dörfler, H. Althues, S. Kaskel, Energy Technol. 2022 submitted.
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Yamagishi, Rena, Anna Sciazko, Yosuke Komatsu, and Naoki Shikazono. "(Digital Presentation) Synthesizing Electrode Microstructures with Predefined Spatial Gradients By Conditional Generative Adversarial Networks." ECS Meeting Abstracts MA2022-01, no. 38 (July 7, 2022): 1683. http://dx.doi.org/10.1149/ma2022-01381683mtgabs.
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Recent progress of manufacturing techniques in the field of solid oxide fuel cells (SOFCs) enables fabrications of complex multi-sized gradient microstructures with the spatially varied properties. Methods using additive manufacturing, layer-by-layer deposition, tape casting, nano-imprint, pulse laser deposition and laser engraving, etc. provide possibilities to fabricate 3D structures with flexible design. Moreover, the spatially optimized structures can provide better mechanical and thermal properties, enhance diffusion and improve electrochemical reaction kinetics. In particular, multi-layered electrode designs are attracting increasing interest. The layered electrode design and optimization require effective methods to fabricate synthetic microstructures with property gradients. The generative adversarial network (GAN) proves its usabilities in fabricating artificial microstructures belonging to the same class as the training data [1] and reconstructing 3D structures from 2D image [2], etc. The applications primarily focus on the structures with uniform spatial properties identical to the training sample. The Wasserstein GAN was recently applied for the fast inverse design of two-phase homogenous microstructures with user-defined properties [3]. In this study, an approach using conditional GAN (C-GAN) is proposed to flexibly generate multi-phase structures with predefined gradients. The proposed method is tested on the microstructures of porous nickel-gadolinium doped ceria (Ni-GDC) SOFC anodes. The C-GAN training dataset consists of real Ni-GDC microstructures with varied Ni and GDC compositions (GDC share in the range of 30 – 70 vol%) and with varied porosity [4]. In total, 10 different samples were prepared and sintered at 1350 oC in air atmosphere and further reduced in the H2 flow at 800 oC. The fabricated electrodes had significantly different microstructural properties and electrochemical performance. The samples were infiltrated with epoxy resin to enable clear phase recognition, polished to expose cross-section and characterized by the scanning electron microscope (SEM). The SEM images were segmented prior to the C-GAN training. The C-GAN was trained with patches of 256 x 256 pixels which were randomly extracted from SEM images of each sample. The sample with Ni : GDC = 50 : 50 vol% was excluded from the training data and used only for testing. The generator network input consists of 4 variables: random noise vector, Ni share in composite, porosity and particle size (Fig. 1A). The particle size is controlled by the magnification of the training images. The Ni volume fraction and porosity are calculated separately for each patch during the iterative training process. The primary version of the trained C-GAN network generates homogenous artificial microstructures with the patch size of 256 x 256 pixels identical to the training data. The fabricated microstructures (Fig. 1B) show excellent visual and good statistical agreements with the real samples. It is possible to reproduce not only the volumetric fractions, but also the surface area density and triple phase boundary density of the real Ni-GDC electrodes (Fig. 1C). The C-GAN can fabricate not only the microstructures belonging to the training dataset, but also samples with other compositions. Although the C-GAN generator was trained based on patches with 256 × 256 pixels, it can be used for the fabrication of larger structures by increasing the size of the generator input. By adjusting the generator input matrix consisting of the Ni share, porosity and particle size, various microstructure patterns can be fabricated including linear gradients (Fig. 1D) and layered structures (Fig. 1E). Those structures have a significance for the SOFC anodes design as layered designs are conventionally incorporated in SOFC electrodes, e.g. support and active anode layers. In addition, it was shown that the graded structures have superior performance compared with the isotropic anodes [5]. The proposed framework provides a convenient tool for generating realistic microstructures with wide range of predefined properties. Further, it can be coupled with the existing simulation tools to evaluate the wide range of graded and layered microstructural designs. [1] A. Gayon-Lombardo, L. Mosser, N. P. Brandon, and S. J. Cooper, npj Comput. Mater., 6, 1–11 (2020). [2] A. Sciazko, Y. Komatsu, and N. Shikazono, ECS Trans., 103, 1363–1373 (2021). [3] X. Lee, et al., Nature Computational Science, 1, 229, (2021). [4] Y. Komatsu, A. Sciazko, and N. Shikazono, J. Power Sources, 485, 229317 (2021). [5] Z. Yan, et al., ECS Trans., 91, 2055, (2019). Fig. 1. A) Schema of C-GAN network, B) synthetic homogenous microstructures fabricated by C-GAN, C) TPB dependence on the Ni and pore volume fractions, D) synthetic structure with predefined gradient and E) synthetic layered structure. Figure 1
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SEGONDS, Frédéric. "Créativité et fabrication additive - Infographie." Fabrication additive – Impression 3D, December 2019. http://dx.doi.org/10.51257/a-v1-ibm7017.
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THOMAS, Marc, Cécile DAVOINE, and Stefan DRAWIN. "Fabrication additive en aéronautique et en spatial." Travail des matériaux - Assemblage, May 2019. http://dx.doi.org/10.51257/a-v1-bm7940.
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Stolidi, Adrien, Anthony Touron, Loïc Toulemonde, Audrey Gardahaut, and Jean-Paul Garandet. "Monitoring en ligne par fluorescence X des procédés de fabrication additive métallique." e-journal of nondestructive testing 28, no. 9 (September 2023). http://dx.doi.org/10.58286/28476.
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Cette communication présente des résultats de spectrométrie par fluorescence X à dispersion d’énergie (ED-XRF) acquis durant des procédés de fabrication additive métallique. Cette technique de caractérisation sans contact et non-destructive est appliquée à deux techniques de fabrication additive métallique. Le but est de renforcer la maitrise de ces procédés et de répondre à des exigences de contrôle qualité. Deux cas d’études sont abordés, l’un concernant des mesures effectuées sur des échantillons possédant une gradation de la composition chimique de l’alliage, l’autre présentant le monitoring des fumées induites durant un procédé de fabrication additive.
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Ait Ouchaoui, Ahmed, Mohammed Nassraoui, and Bouchaib Radi. "L’optimisation topologique pour la fabrication additive : méthodes et limites." Incertitudes et fiabilité des systèmes multiphysiques 7, no. 1 (2023). http://dx.doi.org/10.21494/iste.op.2023.1002.
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MOIGN, Arnaud. "Fabrication additive : état des lieux d’une veille sectorielle et technologique." Fabrication additive – Impression 3D, January 2021. http://dx.doi.org/10.51257/a-v1-as3.
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Saddoud, Romain, Kévyn Perlin, Michel Pellat, and Natalia Sergeeva-Chollet. "Développement de l’outil de contrôle in-situ par Courants de Foucault de pièces en cours de Fabrication pour la technique L-PBF." e-journal of nondestructive testing 28, no. 9 (September 2023). http://dx.doi.org/10.58286/28459.
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Le procédé de fabrication additive par fusion laser sur lit de poudre (L-PBF) est couramment utilisé pour la fabrication de pièces métalliques complexes. Pour garantir la qualité des pièces, une surveillance continue pendant le processus de fabrication par un instrument est nécessaire. Les solutions industrielles existantes sont limitées dans la mesure où elles se limitent à la détection d'anomalies dans les paramètres de l'état de la machine ou dans les couches superficielles de la pièce en cours de fabrication. Le contrôle par courants de Foucault est une méthode prometteuse de contrôle non destructif qui pourrait être appliquée pour l'inspection couche par couche du matériau fusionné pendant la fabrication de la pièce. Cette inspection permet de suivre l'évaluation des défauts non seulement à la surface de la dernière couche fusionnée, mais aussi à l'échelle de plusieurs couches fusionnées. Un capteur à courants de Foucault a été développé et adapté pour effectuer des mesures dans une machine L-PBF pendant la phase de fabrication (in-situ). Les performances et le potentiel de la technique en termes d'intégration et d’évaluation des défauts dans la machine ont été étudiés. Les résultats obtenus ont permis d'évaluer les limites de détection en fonction de la largeur et de la hauteur des défauts pendant la fabrication de la pièce. L'influence de la présence de poudre autour de la zone fusionnée a également été étudiée.
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Palla, Marie, Florian Le Bourdais, and Jean-Paul Garandet. "Caractérisation du champ de température par ultrasons, Application à la fabrication additive par fusion sur lit de poudre." e-journal of nondestructive testing 28, no. 9 (September 2023). http://dx.doi.org/10.58286/28535.
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Les procédés de fabrication additive par fusion laser sur lit de poudre (FLLP) permettent aujourd’hui de fabriquer des composants métalliques à géométrie complexe, aux propriétés performantes. Parmi les différents paramètres impliqués dans le procédé, la température joue un rôle fondamental, car elle contrôle la fusion de la poudre, la solidification et la formation de la microstructure à partir du bain liquide. Différentes techniques existent pour mesurer la température à la surface d’une pièce, comme des mesures par pyromètres ou caméra infra-rouge. Cependant, le champ de température interne reste difficile à estimer par ces méthodes conventionnelles. L’objectif de nos travaux est d’étudier l’évolution du champ de température d’un objet en cours de construction, en proposant une technique de suivi in situ, basée sur la sensibilité des ondes élastiques à la température du milieu de propagation. Un dispositif expérimental a été développé afin de mesurer simultanément des temps de vol en impulsion-écho pendant l’élaboration d’une pièce cylindrique ainsi que températures à l’aide de thermocouples. Un modèle thermique par éléments finis a été développé afin de corréler les variations de temps de vol et de température observées au cours de la fabrication. Dans ce papier, la technique ultrasonore proposée ainsi que les mesures expérimentales réalisées sont exposées. Le modèle et la confrontation de ses résultats aux données expérimentales sont présentés.
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Guitard, Laureen, Adrien Stolidi, Amélie Jarnac, and Jérôme Primot. "Technique d’imagerie par rayons X en contraste de phase pour du contrôle de matériaux composite." e-journal of nondestructive testing 28, no. 9 (September 2023). http://dx.doi.org/10.58286/28531.
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Le contraste de phase en imagerie par rayons X permet de voir des détails de structures dans les matériaux peu absorbants. Plusieurs techniques existent mais l’interférométrie à décalage multilatérale (IDML) permet une mesure simultanée des gradients de phase selon plusieurs directions par un post-traitement dans le domaine de Fourier. Dans cet article nous présentons des résultats de cette méthode sur deux types de matériaux, des polymères issus de fabrication additive biosourcée et des composites carbonés utilisés dans l’aéronautique. Des outils d’analyse d’image sont mis en oeuvre sur les images obtenues.
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Bussy, Victor, Caroline Vienne, Julie Escoda, and Valérie Kaftandjian. "Convolutional Sparse Coding et Dictionary Learning pour la reconstruction tomographique par rayons X pour le contrôle de pièces de fabrication additive." e-journal of nondestructive testing 28, no. 9 (September 2023). http://dx.doi.org/10.58286/28534.
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Cet article évalue le potentiel du convolutional sparse coding (CSC) pour réduire les artefacts dans les images 3D par tomographie rayons X dans le cas où peu de projections sont disponibles. La méthode CSC proposée est testée sur des échantillons métalliques fabriqués par fabrication additive, qui présentent des défis uniques pour les applications de débruitage en raison de la structure fine du matériau. Les résultats indiquent que le CSC surpasse les dictionnaires traditionnels en termes de performance de débruitage et de vitesse de calcul, ce qui en fait une méthode prometteuse pour les applications d'imagerie tomographique à grande échelle.
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Rao, Prahalad K., Jia (Peter) Liu, David Roberson, Zhenyu (James) Kong, and Christopher Williams. "Online Real-Time Quality Monitoring in Additive Manufacturing Processes Using Heterogeneous Sensors." Journal of Manufacturing Science and Engineering 137, no. 6 (September 9, 2015). http://dx.doi.org/10.1115/1.4029823.
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The objective of this work is to identify failure modes and detect the onset of process anomalies in additive manufacturing (AM) processes, specifically focusing on fused filament fabrication (FFF). We accomplish this objective using advanced Bayesian nonparametric analysis of in situ heterogeneous sensor data. Experiments are conducted on a desktop FFF machine instrumented with a heterogeneous sensor array including thermocouples, accelerometers, an infrared (IR) temperature sensor, and a real-time miniature video borescope. FFF process failures are detected online using the nonparametric Bayesian Dirichlet process (DP) mixture model and evidence theory (ET) based on the experimentally acquired sensor data. This sensor data-driven defect detection approach facilitates real-time identification and correction of FFF process drifts with an accuracy and precision approaching 85% (average F-score). In comparison, the F-score from existing approaches, such as probabilistic neural networks (PNN), naïve Bayesian clustering, support vector machines (SVM), and quadratic discriminant analysis (QDA), was in the range of 55–75%.
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Bussy, Victor, Caroline Vienne, Julie Escoda, and Valérie Kaftandjian. "Méthodologie optimisée pour la reconstruction tomographique avec ajout d’informations a priori pour l’inspection par rayons X." e-Journal of Nondestructive Testing 28, no. 9 (September 2023). http://dx.doi.org/10.58286/28692.
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Cet article propose une méthodologie pour améliorer la qualité de la reconstruction tomographique par rayons X en utilisant la connaissance a priori du modèle 3D de l'objet inspecté. Pour cela, la conception assistée par ordinateur (CAO) de l'objet inspecté est intégrée dans les différentes étapes du processus tomographique. Elle permet d’une part de choisir les meilleures vues lors de la phase d’acquisition et d’autre part de réduire le nombre d’inconnues lors de la phase de reconstruction. Cette approche est illustrée sur un exemple issu de la fabrication additive. Les résultats expérimentaux montrent que la méthode proposée permet d'obtenir des reconstructions de meilleure qualité que les méthodes traditionnelles de reconstruction tomographique à partir d’un nombre de vues restreint. Cette approche ouvre des perspectives intéressantes pour améliorer la qualité des images dans des applications industrielles
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Walaszek, Henri, and Mabrouk Ben Tahar. "Acoustique non linéaire en CND : principe, état de l’art, bénéfices attendus." e-journal of nondestructive testing 28, no. 9 (September 2023). http://dx.doi.org/10.58286/28490.
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On regroupe sous le nom d’acoustique non linéaire différentes techniques qui consistent à analyser la réponse ultrasonore des matériaux lorsqu’ils sont soumis à des niveaux d’excitation, le plus souvent élevés. L’analyse peut être effectuée dans le domaine fréquentiel (ex. analyse d’harmoniques supérieures) ainsi que dans le domaine temporel (ex. analyse du temps de vol ou de la phase du signal). L’avantage de cette approche peut consister dans la possibilité d’analyser un composant dans sa globalité et de pouvoir effectuer une analyse plus fine une fois les zones endommagées identifiées. Ceci peut être intéressant quand par exemple, le composant sondé présente un endommagement diffus, non détectable par échographie ultrasonore. Cette contribution évoquera les différentes méthodes acoustiques non linéaires permettant d’effectuer une analyse globale et/ou locale basée sur les harmoniques supérieures ou la résonance pour extraire différents paramètres acoustiques. Seront également présentées les applications des différentes méthodes en termes de santé matière, endommagement, vieillissement/fatigue en lien avec les caractéristiques mécaniques. Ainsi, nous discuterons le degré de non-linéarité des matériaux étudiés et les moyens de sollicitation dynamique nécessaires en liaison avec les équipements disponibles permettant de mettre en oeuvre ces méthodes. L’intérêt et le positionnement des différentes méthodes et technologies dans le paysage CND et dans le cadre de l’émergence de nouveaux procédés, tels que la fabrication additive, sera également discuté. Enfin, un classement méthodes/paramètres recherchés/matériau investigué sera présenté pour donner un aperçu global des méthodologies d’analyse acoustique non linéaire. Tous ces éléments font actuellement l’objet d’échanges au sein du GT « méthodes acoustiques non linéaires » de la COFREND.
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Maulin, Maëva, Nicolas Estre, David Tisseur, Grégoire Kessedjian, Alix Sardet, Emmanuel Payan, and Daniel Eck. "Défloutage de projections tomographiques industrielles hautes énergies à l’aide d’un réseau de neurones convolutifs." e-journal of nondestructive testing 28, no. 9 (September 2023). http://dx.doi.org/10.58286/28481.
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La fabrication additive, métallique en particulier, est en plein essor, mais les pièces ainsi produites peuvent présenter des défauts tels que des anomalies d'impression, de la rétention de poudre ou des fissures. Pour contrôler l'intégrité de ces pièces, la tomographie par transmission haute résolution reste la méthode de référence. Cependant, pour inspecter des pièces massives et fortement absorbantes, la tomographie haute énergie avec un accélérateur linéaire d'électrons est nécessaire. Le Laboratoire de Mesures Nucléaires du CEA IRESNE dispose d'un tomographe haute énergie et a souhaité améliorer la qualité des projections acquises en mettant en place des post-traitements numériques. Afin d’essayer de dépasser les performances des méthodes de restauration classiques, basées sur des algorithmes de déconvolution, une approche de post-traitement novatrice a été étudiée : la déconvolution de flou par réseaux de neurones convolutifs. Pour ce faire, un jeu de données d’images a tout d’abord été généré par simulation. Un réseau de neurones convolutifs, basé sur la structure du réseau SRCNN (Super-Resolution Convolutional Neural Network), a ensuite été adapté, entraîné et évalué. Chaque hyperparamètre du réseau a alors été spécialement optimisé. Enfin, ce réseau a été validé sur des tomographies à 9 MeV d’objets réels afin d’évaluer les performances finales obtenues, mais aussi comprendre les limitations de ce type d’approche. Le réseau de neurones convolutifs ainsi optimisé démontre de bonnes performances de défloutage tout en limitant l’amplification du bruit.
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Foucher, Fabrice, Sébastien Lonné, Philippe Dubois, Stéphane Leberre, Pierre Calmon, Michael Enright, and Yasin Zaman. "Apports d’une cosimulation “END – Tolérance aux dommages” dans la réduction des risques de rupture." e-journal of nondestructive testing 28, no. 9 (September 2023). http://dx.doi.org/10.58286/28527.
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Dans l’approche par tolérance aux dommages utilisée notamment en aéronautique, il est essentiel de démontrer la fiabilité des inspections END pour la détection de potentiels défauts structurels, particulièrement dans le cas de pièces obtenues par fabrication additive car ce procédé introduit d’avantages d’anomalies. Les courbes de Probabilité de Détection (POD), qui relient la probabilité de détecter un défaut à sa taille, constituent un indicateur clé en évaluant une taille maximale de défaut que le procédé END peut manquer à un certain niveau de probabilité et avec un certain taux de confiance. Cette information est utilisée, conjointement à d’autres données telles que la géométrie de la pièce, les propriétés mécaniques, les contraintes ou encore les cinétiques d’évolution des défauts, pour adapter la stratégie de maintenance et de contrôle de la pièce afin d’optimiser la sureté et sa durée de vie en service. La fiabilité d’un END et l’évaluation du risque sont basées sur des indicateurs statistiques qui nécessitent un volume de données important si l’on veut que ces indicateurs soient fiables. Ainsi, il est difficile d’obtenir un bon niveau de confiance sur la base d’une approche purement basée sur des essais expérimentaux compte-tenu du volume de maquettes et des coûts engendrés. Les outils de simulation peuvent atteindre cet objectif s’ils ont la capacité de prendre en compte et piloter précisément les paramètres pertinents et grâce aux capacités de calcul intensif maintenant disponibles. Le travail présenté dans cet article met en oeuvre des cosimulations réalisées entre les logiciels DARWIN®, en modélisation probabiliste de la tolérance au dommage, et CIVA, en modélisation END. DARWIN calcule des niveaux de risque de rupture par zone dans une pièce donnée, quand CIVA permet d’obtenir des courbes de probabilité de détection pour différentes méthodes END. L’application présentée illustre le cas d’une pièce de rotor en titane impliquant un contrôle par ultrasons. Il apparait très pertinent de relier la simulation des END et celle de la mécanique de la rupture, deux disciplines assez compartimentées par ailleurs. En effet, DARWIN permet de connaitre les défauts et les tailles critiques associées qui sont les données d’entrées essentielles pour développer une méthode d’inspection pertinente. CIVA permet d’obtenir des courbes POD permettant ensuite à DARWIN de quantifier le niveau de réduction de risque apporté par cet END. Cela souligne l’importance des END pour la sureté de fonctionnement et permet d’adapter la sensibilité du procédé d’inspection afin de trouver le meilleur compromis entre la performance nécessaire et les coûts
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Dubois, Jean-Marie. "Potential and marketed applications of quasicrystalline alloys at room temperature or above." Rendiconti Lincei. Scienze Fisiche e Naturali, July 3, 2023. http://dx.doi.org/10.1007/s12210-023-01170-4.
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AbstractThe discovery of quasicrystals by Shechtman et al. in 1982–84 has revolutionised our understanding of crystals and order in solids. Shechtman was awarded a Nobel Prize in Chemistry in 2011 to recognize the importance of this breakthrough. Soon after the initial publication, a patent was filed by the author to secure the potential application of these new materials to the fabrication of low-stick surfaces adapted to the industrial production of cooking utensils. Quite a few more patents followed, covering several areas of technological relevance such as low friction, thermal insulation, solar light absorption, etc. The first application failed, although it reached market. Few others never developed to this stage, but also a (very) small number can now be considered as commercially successful. This is especially the case of polymers reinforced with a quasicrystal powder that are especially adapted to additive manufacturing or 3D printing. Also very advanced is the use of a blend of quasicrystalline and complex intermetallic powders to mark and authenticate an object in a way that cannot be counterfeit. The present article reviews the state of the art and outlines the physics behind few technological breakthroughs that are based on quasicrystalline alloys in the areas of mechanical engineering and solid–solid or solid–liquid adhesion. For the sake of brevity, applications in the areas of catalysis, solar and thermo-electric devices are only shortly evoked. Graphical abstract
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Lengger, Michael, Gunnar Possart, and Paul Steinmann. "A viscoelastic Mooney–Rivlin model for adhesive curing and first steps toward its calibration based on photoelasticity measurements." Archive of Applied Mechanics, October 20, 2022. http://dx.doi.org/10.1007/s00419-022-02273-4.
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AbstractThe transition of polymer adhesives from an initially liquid to a fully cured viscoelastic state is accompanied by three phenomenological effects, namely an increase in stiffness and viscosity in conjunction with a decrease in volume (curing shrinkage). Under consideration of these phenomena, some of us (Hossain et al. in Computational Mechanics 46:363-375, 2010) have devised a generic, viscoelastic finite strain framework for the simulation of the curing process of adhesives, which renders a thermodynamically consistent model regardless of the selected free energy density. In the present work, this generic curing framework is modified by means of more precise integration schemes and is applied to a hyperelastic Mooney–Rivlin material based on an additive volumetric-isochoric split of the strain energy density. The benefit of this decomposition is directly related to the distinct material responses of various polymers to volumetric and isochoric deformations [4]. The resulting Mooney–Rivlin curing model provides the foundation for implementing a user-defined material subroutine (UMAT) in Abaqus requiring the Cauchy stress and a non-standard formulation of the tangent operator. To this end, the corresponding transformations are presented. Additionally, a first attempt to determine the evolution of the curing-dependent material parameters through optimization with respect to a photoelasticity measurement is presented. A subset of the material properties, which reflect the emergence of shrinkage stresses inside a ceramic-epoxy composite after its fabrication, is determined via inverse parameter identification. However, due to a lack of experimental data and some rather strong assumptions made on the physics involved, this demonstration can currently be considered only as a proof-of-concept.
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Wang, Tian‐yun, Yang‐yang Hao, Ming‐zhe Zhu, Guo‐rui Cao, and Zhong‐min Zhou. "Hydrogen Bonds in Perovskite for Efficient and Stable Photovoltaic†." Chinese Journal of Chemistry, February 13, 2024. http://dx.doi.org/10.1002/cjoc.202300651.
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Comprehensive SummaryOwing to their distinctive optical and physical properties, organic‐inorganic hybrid perovskite materials have gained significant attention in the field of electronic devices, especially solar cells. The achievement of high‐performance solar cells hinges upon the utilization of top‐notch perovskite thin films. Nevertheless, the fabrication process involving solutions and the polycrystalline nature of perovskite result in the emergence of numerous defects within the perovskite films, consequently exerting a deleterious influence on the overall performance and stability of the devices. Improving the performance and stability of perovskite solar cells by additive engineering to suppress/passivate defects is a viable approach, which involves hydrogen bond interactions in these device engineering processes. This review explores the intrinsic hydrogen bonds in methylammonium and formamidium lead triiodide, while also considering cation rotations, phase transitions, and stability. Moreover, the review classifies additives into distinct categories, including organic small molecules, polymers, nanodots, classical salts, ionic liquids, and molten salts. The various forms and characterization techniques of hydrogen bonds are discussed, as well as their potential synergistic effects in conjunction with other chemical interactions. Furthermore, this review offers insights into the potential utilization of hydrogen bonds to further enhance the performance and stability of devices. Key ScientistsIn 2009, Tsutomu Miyasaka et al. prepared the first perovskite solar cell, which kicked off the research on perovskite light‐absorbing materials. However, the use of liquid electrolytes led to device instability. The transition to all‐solid‐state perovskite solar cells was realized by Nam‐Gyu Park's team in 2012, which was the beginning of high‐efficiency perovskite solar cells. Subsequently, a number of scientists have innovated the preparation ground process. Methods such as two‐step deposition by Michael Grätzel in 2013 and anti‐solvent extraction by Sang II Seok's team in 2014 were instrumental in advancing the development of perovskite. Liyuan Han's team then increased the cell's working area to 1 cm2 without compromising performance, making it possible to compare the performance metrics of perovskite solar cells with those of other types of solar cells on the same scale. Recently, You's team and Pan's team kept updating the world record by obtaining certified efficiencies of 25.6% and 25.8% in 2022 and 2023, respectively.