Track C
Computational Tools in Materials Synthesis and Processing Science
ABSTRACTS
Session C-1 0D, 1D and 2D nanomaterials and nanostructures
C-1:IL02 Theoretical Design and Modeling of 2D Conjugated Polymer for Overall Water Splitting under Visible Light
XIAOJUN WU, University of Science and Technology of China, Hefei, China
Using solar energy to split water to prepare hydrogen and oxygen is an important way to obtain clean hydrogen energy and solve energy and environmental problems.Direct catalytic decomposition of water using semiconductor photocatalytic materials absorbing solar energy is a promising way, but it is necessary to find photocatalysts with appropriate bandgap, band-edge positions, and surface reactivity. In this talk, we developed a material design strategy based on topological assembly of molecules and first-principles calculation. With this strategy, we reported a series of 2D conjugated polymer photocatalysts that can fully decompose water using visible light, revealed the reaction mechanism in the process of photodegradation of water, and further modified the photocatalytic performance of the materials through chemical modification. The photocatalytic performance of the materials was further modulated by chemical modification. Several 2D conjugated polymers that can fully decompose water under visible light irradiation were reported.
C-1:IL04 3D Printed Functional MXene-based Ceramics
S. BARG, University of Augsburg, Institute of Materials Resource Management, Augsburg, Germany
MXenes are a family of 2D materials showing a wide range of functional properties such as high electrical and thermal conductivities, mechanical strength, EMI shielding and catalytic properties for certain chemical reactions. Their effective incorporation into ceramic matrixes can open new opportunities to develop materials with enhanced performance and functionalities for applications beyond ambient conditions. MXenes high aspect ratio, aqueous dispersion stability, and tuneable surface chemistry, further make them well-suited for colloidal processing, including 3D printing. Here, we investigate the possibilities to develop printable MXene-based ceramic structures. By designing efficient MXene-based formulations, we show it is possible to create colloidal inks with ideal rheological properties for printing intricate and complex ceramic structures via extrusion-based 3D printing, i.e., direct ink writing, DIW. We further elucidate the challenges and opportunities for their consolidation using novel pressureless sintering methods. The results open-up exciting opportunities to print functional MXene-based ceramics for potential use in a myriad of applications requiring functional and structural properties.
C-1:L05 Molecular Dynamics Investigation of Nanoparticle Coalescence under Realistic Gas-phase Synthesis Conditions
P. Grammatikopoulos1, 2, S.E. Pratsinis2, 1Department of Materials Sciences and Engineering, Guangdong Technion Israel Institute of Technology, Shantou, Guangdong, China; 2Particle Technology Laboratory, Institute of Process Engineering, Department of Mechanical and Process Engineering, ETH Zürich, Zürich, Switzerland
Dependence of nanoparticle (NP) coalescence on physical parameters (e.g., temperature, NP size, orientation, crystallinity, shape, or composition, etc.) is an active field of investigation. However, most computational studies on NP coalescence to date are performed in vacuum, with only a handful of studies taking gas pressure into account. This is due to two reasons: first, many computational studies complement inert-gas condensation experiments, which typically happen at high vacuum. Second, a simulation set-up in vacuum computationally less costly. Here we utilised classical molecular dynamics for a rigorous investigation of the effect (or lack of) gas pressure on the early stages of coalescence between two metallic NPs, as well as of other parameters (temperature, angular momenta, and inert-gas species). Our approach is relevant for both inert-gas condensation and aerosol synthesis in standard conditions. Multiple linear regression analysis confirmed temperature as the key factor determining the degree of coalescence; relative angular momenta direction was revealed as yet another important contributor, whereas the effect of pressure was deemed insignificant for early coalescence stages (less so for later ones), indicating potential strategies for both synthesis methods.
Session C-2 Soft condensed matter systems
C-2:L03 Study of Colloidal Aggregate Morphology in a Confined Environment using SRD-MD
H. SEMAAN1, 2, M. Cerbelaud1, J. Gerhards1, B. Crespin2, R. Ferrando3, A. Videcoq1, 1Univ. Limoges, CNRS, IRCER, UMR 7315, Limoges, France; 2Univ. Limoges, CNRS, XLIM, UMR 7252, Limoges, France; 3Physics Department, University of Genoa, Genoa, Italy
Colloidal suspensions, crucial in various industries, especially ceramics, play a vital role in shaping. Understanding particle arrangement and rheological behavior is essential for shaping control and desired ceramic properties. Numerical simulations help unravel suspension behavior. In ceramics, suspensions encounter vital constraints like confinement and flow, requiring simulations with hydrodynamic effects for a deeper understanding in ceramic applications. In this presentation, we will introduce the hybrid stochastic rotation dynamics-molecular dynamics SRD-MD method, a mesoscopic simulation that tracks colloidal particle trajectories in suspensions, including hydrodynamic effects. This method combines SRD for fluid particle dynamics and MD for colloidal behavior. We'll demonstrate how SRD can simulate Poiseuille flow between two infinite planes and how colloids are integrated for simulating colloidal suspensions in flow. Furthermore, we will investigate the effect of varying shear on the aggregation process. We'll closely examine how repulsive and attractive walls further influence aggregation under shear, revealing diverse outcomes. Finally, we will explore how the ratio between particle size and the distance between walls contributes to shaping these observed phenomena.
Session C-3 Powders, granular materials, single crystal growth
C-3:IL01 Multi-scale Modelling of Single-crystal Diamond Gowth via the HPHT Process
J.J. DERBY, S.S. Dossa, University of Minnesota, Minneapolis, MN, USA; I. Ponomarev, Euclid Beamlabs, Beltsville, MD, USA; B. Feigelson, US Naval Research Laboratory, Washington, DC, USA; M. Hainke, C. Kranert, J. Friedrich, Fraunhofer IISB, Erlangen, Germany
Lab-grown diamond single crystals are of great interest for future applications in high-fluence X-ray optics, power electronics, and quantum computing. The high-pressure, high-temperature (HPHT) process is capable of growing large, high-quality diamond single crystals, of centimeter size and with dislocation densities less than 10 cm-2, from a molten metallic flux, or solvent, under pressures of 5 GPa (50,000 atmospheres) and temperatures of 1,500 K. Since in situ diagnostics are impossible to implement under such harsh conditions, we have developed and employed a multi-scale, continuum-level computational model to probe the mechanistic underpinnings of HPHT diamond growth. This model is the first to rigorously connect carbon transport through the solvent to phase-change kinetics of growth along the crystal facets. We present model results showing the importance of solvent flow, carbon transport, and temperature distribution and show that growth rate predictions compare favorably to experimental observations. Results also indicate that inhomogeneities in supersaturation arise along the growth interfaces, particularly for larger crystals. We discuss ongoing work to apply models for step motion along the diamond facets to assess inclusion formation processes during crystal growth.
C-3:IL02 Theoretical Modeling of Nucleation and Growth of Particulate Matter
ZHENYHU LI, Key Lab. of Precision and Intelligent Chemistry, University of Science and Technology of China, Hefei, China
Molecular simulations are performed to study nucleation and growth of particulate matter in the atmosphere. Enhanced sampling techniques are used combining with machine learning potentials to obtain the free energies of clusters with different sizes. At the same time, the dynamic nucleation theory (DNT) is extended by introducing new reaction coordinates and considering multiple evaporation channels. The extended DNT is used to obtain evaporation rate of small molecular clusters. H2O and H2O/H2SO4 clusters are studied and implications to nucleation and growth of particulate matter are discussed.
C-3:IL03 Reassessment of the Criterion for Layer-by-layer Metal Growth: What Determines the Ehrlich-Schwoebel Barrier?
H. JONSSON, Science Institute and Faculty of Physical Sciences, University of Iceland, Reykjavík, Iceland
The energy barrier for adatom downstepping at a step edge is a critical feature of the energy landscape, the so-called Ehrich-Scwoebel barrier (ESB). At high temperature, thermal energy suffices to overcome the ESB, giving layer-by-layer growth (LBLG), while at lower temperature nucleation of a new island occurs on top of an existing one, i.e. 3-D growth. Remarkable observations have, however, been made in experiments, e.g. Pt(111), where further lowering of the temperature leads to LBLG, i.e. re-entrant LBLG [1]. Early calculations based on potential functions identified a 'hole' in the ESB near, but not at, kink sites on step edges of islands [2]. However, our recent DFT calculations of a Pt adatom on top of a striped island on Pt(111) have revealed another feature calling for re-evaluation of the ESB. Elastic strain induced variation of the binding energy and migration barrier as the adatom approaches the step edge is found. The small islands formed at low temperature, in particular arms of dendritic islands, thereby have low ESB. This changes he notion of the ESB and the way it should be calculated theoretically. [1] R. Kunkel, B. Poelsema, L. K. Verheij, and G. Comsa, Phys. Rev. Lett. 65, 733 (1990). [2] H. Jónsson,, Annual Review of Physical Chemistry, 51, 623 (2000).
C-3:L04 Aerosol Processing of Materials: Inelastic Collisions and the Gas Mean Free Path
D. Tsalikis, V. Mavrantzas, S.E. Pratsinis, Particle Technology Laboratory, Institute of Process Engineering, Department of Mechanical & Process Engineering, ETH Zurich, Switzerland and Department of Chemical Engineering, University of Patras, Greece
Recent advances in understanding of combustion and aerosol formation and growth through multiscale process design allow now inexpensive synthesis of nanoparticles with sophisticated composition, size and morphology by flame spray combustion at kg/h even at an academic institution with such units now all over the world (UK, Spain, India etc.). These have led to synthesis of single noble atom heterogeneous catalysts, highly porous self-assembled lace-like or cauliflower-like gas sensing films and biomaterials that have been commercialized by spinoffs from our laboratory. For eons, the kinetic theory of gases has been used to determine the mean free path of gases assuming elastic collisions between spherical molecules. However, is this so with what we know about molecular shape and force fields today? Having reached a state of maturity now, molecular dynamics simulations can elucidate the fundamentals of basic gas-phase (aerosol) processes that lead to better understanding of natural phenomena and accelerating process scale-up. Here the mechanics of gas collisions are elucidated for plain air at room temperature by thoroughly-validated atomistic MD treating O2 and N2 as true diatomic molecules accounting for their shape and force field, for the first time to our knowledge.
C-3:IL05 Impact of Configurational Entropy on Point Defect Thermodynamics in Crystalline Silicon
T. SINNO, Dept of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, PA, USA; J. Luo, L. LIU, School of Energy and Power Engineering, Xi’an Jiaotong University, Xi’an, Shaanxi, China; J.F. Douglas, Material Measurement Lab., Material Science and Eng. Division, National Institute of Standards and Technology, Gaithersburg, MD, USA
It has long been suggested that intrinsic point defects (vacancies and self-interstitials) in silicon transform into extended, disordered domains characterized by missing or excess atoms at sufficiently high temperature. Such “extended defects” may be viewed as droplet-like regions of enhanced or diminished density with thermodynamic and transport properties that are quite different from those associated with the respective ground states. Yet the implications of such a transformation, or whether it even occurs in crystalline Si, remain uncertain. Here we consider a comprehensive thermodynamic analysis of the thermodynamics of vacancy and self-interstitial formation over a broad temperature range based on thermodynamic integration with a particular focus on entropic contributions. We analyze several empirical Si potentials to determine how the potential influences the configurational entropy, as well as the enthalpy and entropy of defect formation. We show that the configurational entropy associated with point defects increases significantly upon heating, consistent with the existence of extended defects. We discuss potential consequences of these thermodynamic changes on the temperature dependence of diffusion in heated crystals as well as the onset of melting.
C-3:IL06 Modeling of Solidification Processes under Consideration of Particle Transport in the Melt for Terrestric and Microgravity Conditions
H. Koch1, P. Ott2, T. Jauß2, T. Sorgenfrei2, M. Hainke1,3, C. Kranert1, J. Friedrich1, 1Fraunhofer IISB, Erlangen, Germany; 2University of Freiburg, Crystallography, Freiburg, Germany; 3Ostbayerische Technische Hochschule (OTH), Amberg-Weiden, Germany
In this work the interaction of solid-state particles with the moving water-ice solidification front under terrestrial and microgravity conditions is studied by numerical simulations as well as by experiments. In basic studies, the thermal conditions of the solidification processes were systematically varied and their influence on the solidification front were investigated. It was found that there is only a minor influence on the solidification process whether the experiments are carried out under terrestrial or microgravity conditions. For the simulation of the TEXUS sounding rocket experiments, the injection of the particles, their transport through the fluid and their interaction with the interface were considered in the simulations. The simulation results agree reasonably to the experimental data with respect to the temporal evolution of the solidification front. It was also confirmed that the injection of the particles causes a forced flow disturbing the solidification process for a short time period and that the resulting particle distribution in the fluid is comparable. The experiments agree also to the theoretical considerations that under the given conditions large particles are captured instantly, while the smaller ones are pushed ahead by the phase boundary.
Session C-4 3D-bulks, composites and porous materials
C-4:IL01 Valence Stability of Cerium Ions in Various Oxide Lattices: Revisiting of Madelung Lattice Site Potential Calculation
MASAHIRO YOSHIMURA1, 2, K. SARDAR1, 1National Cheng Kung University, Tainan, Taiwan; 2Tokyo Institute of Technology Japan
The valence state of Cerium ions(+3 or +4) is really important term in various functional oxides like catalyst, fluorescent and/or photo-electronic, and/or magnetic materials. Several experimental ad theoretical explanations have been seen in literature, however, most of them would be just phenomenological but not quantitative. The author had explained this problem semi-quantitatively in previous papers (1-3)
The Valence stability of an Ion should be co-related to the Lattice site potential (Φ) because Ionization potencial of the Ion can be balanced with the lattice site potential of the ion in the lattice site of various crystal lattices. After the Calculations,one can conclude that Ce3+ can be located in the site (Φ = -1.9 ~-2.0 A-1) , while Ce4+ can be in the site (Φ =-2.7-2.8 A-1), regardless to the Crystal symmetry and/or type.
Recently more precise calculation of the Madelung Lattice energy(U) and Lattice site potential using 1st principle and/or molecular dynamics become possible thus those problems will be solved by those calculation, then confirmed by careful and in-situ analysis for various oxide lattices.
1) M. Yoshimura, et al. Bull. Tokyo Inst. Tech.,120, 13-22 (1974)
2) M. Yoshimura, Valence Stability of Rare Earth Ions, (in Japanese), Chapter 34,pp 851-862, Kidorui (Rare Earth) Handbook, Edited by G. Adachi, NTS Book Co. Ltd. Tokyo,2008.
3) M. Yoshimura, K. Sardar, RSC Advance, 11(34),29737-20745 (2021)
C-4:IL02 A Framework for a High Throughput Screening Method for Polymeric Systems using Molecular Dynamics
L. Smith, H.A. Karimi-Varzaneh, S. Finger, G. Giunta, A. Troisi, P. Carbone, Department of Chemical Engineering, School of Engineering, The University of Manchester, Manchester, UK; Continental Reifen Deutschland GmbH, Hanover, Germany; BASF, Ludwigshafen, Germany; Department of Chemistry, Liverpool, UK
Polymer informatics is a growing area of material science that aims at applying Machine Learning techniques to predict and optimize polymeric materials. Compared to other fields of material science, however, available curated experimental data for polymers are scarce due to the high variability of the experimental samples unique to these materials. In this work we present a procedure to potentially screen thousands of molecules (diluents) for their miscibility in polymer matrices. Using ad-hoc molecular dynamics simulation set-ups that are relatively computationally inexpensive, we establish correlations between the molecules’ topology, internal flexibility, thermodynamics of aggregation and their degree of miscibility and use these to classify the molecules as miscible or immiscible. The fully automated method is able to screen molecules with high miscibility potential on which further simulations or experiments can be performed. This procedure enables a 10-fold reduction of the test space and provides the basis for the development of a simulation procedure which can efficiently screen thousands molecules with a variety of features.
Session C-5 Thin/Thick films, layered structures and surface processing
C-5:IL01 Contribution of Molecular Dynamics to the Study of Metallic Nanometric Multilayers
O. POLITANO1, Y. Li1, V. Turlo2, F. Baras1, 1Lab.Interdisciplinaire Carnot de Bourgogne, UMR 6303, CNRS-Université de Bourgogne, Dijon, France; 2Lab. for Advanced Materials Processing, Empa - Swiss Federal Labs for Materials Science and Technology, Thun, Switzerland
Nanometric metallic multilayers (NMMs), made of hundreds of nanometric layers, exhibit exceptional properties. Deposit techniques are employed to produce NMMs in the form of coatings or free-standing foils, while multiple rolling-stacking methods result in cost-effective nanocomposites. Compared to monolithic films, both systems show exceptional properties as they combine the unique properties of individual metals and a large number of interfaces. To develop new applications, it is essential to understand the thermal behavior of NMMs. However, experimental approaches are challenging at the microscopic scale. Molecular dynamics simulations offer a promising alternative, thanks to their ability to capture the typical length scale of the system under investigation. In this presentation, we will highlight our recent findings on the self-propagating reaction in Ni/Al reactive nanocomposites [1] and the thermal stability of Ag/Ni immiscible N2Ms [2].
[1] O. Politano and F. Baras, Reaction front propagation in nanocrystalline Ni/Al composites: A molecular dynamics study, J. Appl. Phys. 128, 215301 (2020).
[2] F. Baras, Y. Li, V. Turlo and O. Politano, Thermal stability of Ag-Ni nanometric multilayers: a molecular dynamics study, Nanomaterials 13, 2134 (2023).
C-5:IL02 Experimentally Validated Discrete Element Method Framework for Modeling Laser-material Interactions with Multiple Reflections applied to Nanoparticle-assisted Microwelding of Copper
V. TURLO, Empa - Swiss Federal Laboratories for Materials Science and Technology, Thun, Switzerland
This lecture introduces a novel discrete element method framework for simulating laser-matter interactions on rough surfaces and powder beds. Integrating photon-type immaterial Lagrangian particles, the method captures intricate phenomena including multiple reflections, angle-dependent reflectivity, and polarization changes across surfaces with arbitrary geometry and roughness. Its efficacy is underscored by successful validation against experimental measurements of effective reflectivity on a rough copper sample, emphasizing the critical role of polarization effects. Additionally, the framework’s application to powder beds has culminated in a theoretical model for evaluating effective reflectivity in sparse powder layers. This helped in understanding the mechanisms of copper welding using short-wavelength lasers, revealing that nanoparticles redeposited from the vaporized plume substantially enhance surface absorptivity. The combined experimental-theoretical analysis further disclosed a 70% increase in absorptivity and a 50% reduction in melting threshold power density. This enables energy-efficient, high-quality microwelding applications in diverse industries, including consumer electronics and electric vehicles.
C-5:IL03 Formation of Lattice-aligned Gallium Oxynitride Nanolayer on Gallium Nitride
JUNLEI ZHAO, J. Chen, M. Hua, Southern University of Science and Technology, Shenzhen, China
Gallium nitride (GaN), a vital wide bandgap semiconductor alternative to silicon, finds extensive use in photoelectronic and electronic technologies. However, the vulnerability of GaN surfaces hampers device stability and reliability. We address this challenge by transforming GaN surfaces into a gallium oxynitride (GaON) epitaxial nanolayer via an in situ two-step "oxidation–reconfiguration" process. O plasma treatment overcomes GaN surface inertness, and sequential thermal annealing manipulates reaction pathways, forming a metastable GaON nanolayer with a wurtzite lattice. The construction and formation mechanisms of the GaON nanolayer are explained through well-established experimental and computational methods. The band alignment of the GaON nanolayer on the GaN substrate is verified through experimental characterization and theoretical calculations. This tailored GaN-derived GaON nanolayer reinforces surfaces, offering a wide bandgap, high stability, and significant valence band offset with the GaN substrate. These properties enhance GaN-based device performance across applications like power systems, logic circuits, photoelectrochemical water splitting, and ultraviolet photoelectric conversion.
C-5:L04 Tunable Fano-resonant Thin-film Optical Filters
YI-SIOU HUANG, C.Y. Lee, I. Takeuchi, C.A. Ríos Ocampo, Department of Materials Science and Engineering, University of Maryland, College Park, MD, USA
Fano resonance in thin films occurs when a broadband absorber is coupled with a narrowband absorber. Such a structure was first demonstrated in the visible spectrum by ElKabbash et al. in 2021, Here, we use the phase-change material (PCM), Sb2Se3 (SbSe), which allows the Fano resonance to exist, with the added nonvolatile tunability by switching the PCM between its amorphous and crystalline states. In our SbSe/Ag/ITO/Ag PCM-FROC structure, we successfully demonstrate a nonvolatile tunable optical filter with narrowband reflection and transmission. By implementing the machine learning (ML) inverse design, we find the optimal layers thickness for multi-objective optimization. Furthermore, by adding an extra SiO2 layer into our PCM-FROC structure, the Ag/SiO2/ITO/Ag stack forms a capacitor. When applying a voltage, charges accumulate in the ITO film, which induces a strong refractive index variation and thus, allows to tune the wavelength of the transmission and reflection peaks. Therefore, we achieve two main modulation mechanisms in the same structure: a volatile tuning via ITO charge doping, and a nonvolatile via PCM switching. Our work paves the way for ultra-thin-film optical filters and structural color coatings with strong tunable response in the visible and near-infrared.
C-5:L05 Prediction of Thermal Stresses in NiTi Coating Layer on Substrate Stainless Steel using Simulation Method by Comsol Multiphysics
S. SAMAL, FZU-Institute of Physics of Czech Academy of Science, Prague, Czech Republic
A thick coating consisting of two layers (top NiTi coating , base stainless steel (AISI 304) substrate, carrier layer (SS 316L)) is stress and strain free at 800°C. The temperature of the plate is reduced to 150°C, which induces thermal stresses. A third layer, the carrier layer, is then activated in a stress-free state. The temperature is finally reduced to 20°C. The distribution of stress within the layer from substrate to coating is predicted at deposition temperature and normal temperature using Comsol Multiphysics. The plate is considered to be thick and therefore in a state of plane strain. It is modeled using the 2D Solid Mechanics interface. The bottom layer of the geometry is the carrier, the middle layer is the substrate, and the top layer is the coating. The three layers are modeled as isotropic and linear elastic. The substrate material has a higher coefficient of thermal expansion (17.3e-6) than the coating material (11e-6). This means that the substrate shrinks more than the coating, causing tensile stresses in the substrate area next to the coating and compressive stresses in the coating.
Session C-6 Additive manufacturing of multiscale and multi-material structures
C-6:IL01 Additive Manufacturing of Hierarchically Structured Ceramics for CO2 Capture
M. D’Agostini1, M. Cavallo2, N.G. Porcaro2, F. Bonino2, V. Crocellà2, P. Colombo1, 3, G. Franchin1, 1Department of Industrial Engineering, University of Padova, Padova, Italy; 2Department of Chemistry, NIS and INSTM Centres, University of Torino, Torino, Italy; 3The Pennsylvania State University, Department of Materials Science and Engineering, University Park, PA, USA
Anthropogenic CO2 emissions are a primary driver of the greenhouse effect. Carbon capture and storage technologies offer solutions to combat CO2 emissions, with solid sorbents emerging as a promising option. They must meet crucial criteria, including high CO2 sorption capacity, cost-effectiveness, and adaptability to existing infrastructure. This discussion proposes to fulfill these requirements by leveraging additive manufacturing technologies, specifically material extrusion, to produce hierarchically porous, structured sorbents. The initial approach involves using geopolymers as the matrix material. Geopolymers are appealing due to their substantial porosity, which enhances access to any active filler phase. A second approach capitalizes on the similarities between geopolymers and zeolites, proposing the in-situ crystallization of structured zeolite sorbents. All materials undergo pure CO2 adsorption/desorption isotherms and dynamic breakthrough assessments. The impact of various geometries on dynamic CO2 adsorption is assessed. The presented sorbents exhibit CO2 adsorption capacities on par with commercial benchmarks and offer ease of customization and seamless integration into existing facilities.
C-6:L02 Optimizing 3D and 4D Printing for Numerous Applications: The Impact of Computational Models
T.J. WEBSTER, Hebei University of Technology, Tianjin, China and Interstellar Therapeutics, Mansfield, MA, USA
Additive manufacturing, specifically 3D printing, has revolutionized numerous industries from construction to medicine. However, the role of computational modeling in 3D printing suitable structures for these applications remains untold. This presentation will discuss how computational modeling is being used to 3D print novel materials for electronic, aerospace, wind mill, jet engine, boat, medical device and other applications with improved properties over those made by conventional manufacturing. It will introduce equations that can be used to 3D print structures with suitable surface properties to improve various applications. Impressively, it will emphasize 3D printed materials that are currently being used commercially. Lastly, it will introduce 4D printing which is a new additive manufacturing process in which the shape of a 3D printed structure can be controlled with time and on-demand opening the possibility for numerous flexible electronic and medical device applications. In summary, this talk will emphasize how computational modeling has and is being used to improve 3D and 4D printing for improved structures.
C-6:IL03 Optimizing the Design and Manufacturing of Bioceramic Scaffolds towards Bone-like Architectures
F. BAINO1, R. Gabrieli1, A. Schiavi2, G. Orlygsson3, M. Schwentenwein4, L. D’Andrea5, P. Vena5, E. Verné1, 1Institute of Materials Physics and Engineering, Department of Applied Science and Technology, Politecnico di Torino, Turin, Italy; 2National Institute of Metrological Research (INRiM), Applied Metrology and Engineering Division, Turin, Italy; 3Ice Tec, Reykjavik, Iceland; 4Lithoz GmbH, Vienna, Austria, 5Department of Chemistry, Materials and Chemical Engineering “Giulio Natta”, Laboratory of Biological Structure Mechanics (LaBS), Politecnico di Milano, Milano, Italy
Biomaterials are often produced in the form of porous scaffolds acting as templates to allow tissue growth and regeneration in 3D. Ideally, structural biomimicry is a commonly-followed criterion so that the scaffold can replicate the trabecular architecture of bone. This is a particularly difficult task when bioactive ceramics and glasses are used for osseous applications due to some challenges related to the inherent characteristics of materials and relevant fabrication processes (e.g. reproducibility, reliability and the need for consolidation via high-temperature sintering). Recent progresses in the advanced manufacturing of bioceramics have allowed researchers to overcome some of these limitations. The first part of this contribution provides a state-of-the-art overview of porous bioceramics fabrication by conventional and additive manufacturing technologies. The second part is addressed to the strategies developed to integrate the design of bone-like structures, also driven by computational tools, into additive manufacturing methodologies, with emphasis on scaffolds exhibiting foam-like architecture and triply-periodic minimal surfaces (TPMS), which is also the topic of a recent collaboration between the authors of this contribution.
Session C-7 Data driven, machine learning to accelerate and optimize materials processing
C-7:IL01 Machine Learning for Prediction of Combustion Synthesis Kinetics and Properties of Combustion-derived Solid Solutions
S. VOROTILO, King Abdullah University of Science and Technology (KAUST), Saudi Arabia; K. Sidnov, V. Kurbatkina, D.O. Moskovskikh, National University of Science and Technology MISiS, Moscow, Russia
The rapid advancement in machine learning (ML) technologies has opened new avenues for enhancing efficiency and prediction accuracy in various scientific domains. Combustion synthesis (CS) is recognized as a versatile and extremely energy-efficient method for creating a wide array of materials, including advanced solid solutions-based ultra-high temperature ceramics for hypersonic applications. However, the complexity of combustion in solid reactive mixtures challenges the prediction of reaction kinetics, hindering the industrial viability of CS-based processes. This study leverages ML algorithms to predict the kinetics and properties of combustion-derived solid solutions, aiming to optimize the synthesis process. Through literature review and experimentation, various ML algorithms were evaluated for predicting key parameters influencing CS kinetics and the properties of resultant solid solutions. Preliminary findings show promise in utilizing ML to enhance prediction accuracy, optimize CS processes, and improve the industrialization prospects of CS-based material synthesis. Future work will focus on refining ML models and exploring real-world applications of the optimized CS process.
C-7:L02 Multi-objective Optimization of Silver-nanowire Deposition for Flexible Transparent Conducting Electrodes
J.W.P. HSU, M. Lee, R. Piper, B. Bhandari, University of Texas at Dallas, Richardson, TX, USA
Transparent conducting electrodes (TCEs) are vital components in energy applications like LEDs, photovoltaics, and thin-film transistors. Achieving high transparency and high conductivity simultaneously is challenging because of the competing nature of the two physical quantities. For solution-processed TCEs on flexible PET substrates, the conductivity of indium zinc oxide (IZO) films is increased through the incorporation of silver nanowires (AgNWs). We focus on optimizing the spin-coating of AgNWs, as they primarily determine the transmittance and conductance of TCEs, using machine learning (ML) to achieve high transmittance and low sheet resistance simultaneously. This optimization involves mapping three inputs (AgNW solution concentration, spin speed, and dispense volume) to two outputs (transmittance and sheet conductance). Using a scalar figure of merit for optimization cannot satisfy the independent requirements on transmittance and conductance imposed by specific applications. Instead, we employ two separate Gaussian process (GP) regression models for transmittance and conductance, enabling Pareto front analysis. Our results reveal that achieving transmittance ≥ 75% and sheet resistance ≤ 15 Ω/sq is challenging but feasible using parameters identified by the ML analysis.