The smart robot crafting approach to computing materials

This study presents a universal method that combines robotic/mechanical automation with image processing and artificial intelligence (AI) to generate material models without any pre-existing knowledge of the material itself. Inspired by the “hand-eye-mind” process, used typically in designing and crafting, this study proposed a digital version of the process that is capable of automatically conducting a large number of material experiments, observing them using image recognition, and subsequently training AI. The proposed method generates neural network models for common digital design environments that help to bridge a wide range of design intentions, fabrication controls, and dynamic material behaviors. In this study, two different experiments were conducted using the same method. The first one generated a material model for the bending behavior of non-linear synthetic rubber, and the other involved the dynamic control of the form-finding process of thermoplastics based on dynamic annealing, which contributed to a new 3D printing method. With current progress, we are able to prove that such a workflow is a widely adaptable method that encompasses a large variety of material properties and fabrication methods. It enables design and construction using complex material behaviors without the support of existing material/structure models

Integrated Computing Accelerates Design and Performance Control of New Maraging Steels

This paper mainly used database technology, machine learning, thermodynamic calculation, experimental verification, etc., on integrated computational materials engineering. The interaction between different alloying elements and the strengthening effect of precipitated phases were investigated mainly for martensitic ageing steels. Modelling and parameter optimization were performed by machine learning, and the highest prediction accuracy was 98.58%. We investigated the influence of composition fluctuation on performance and correlation tests to analyze the influence of elements from multiple perspectives. Furthermore, we screened out the three-component composition process parameters with composition and performance with high contrast. Thermodynamic calculations studied the effect of alloying element content on the nano-precipitation phase, Laves phase, and austenite in the material. The heat treatment process parameters of the new steel grade were also developed based on the phase diagram. A new type of martensitic ageing steel was prepared by selected vacuum arc melting. The sample with the highest overall mechanical properties had a yield strength of 1887 MPa, a tensile strength of 1907 MPa, and a hardness of 58 HRC. The sample with the highest plasticity had an elongation of 7.8%. The machine learning process for the accelerated design of new ultra-high tensile steels was found to be generalizable and reliable

Cellular traction force measurement based on patterned elastic substrate

Abstract： Cell traction force microscopy method is one of the mainstream tools for measuring cell traction force, which uses fluorescent microbeads as markers to measure the deformation of the substrate and calculate cell traction force. However, due to the random distribution of fluorescent microbeads in the substrate, the calculation accuracy of the cell traction force field maybe affected. To address the problem of uncontrollable depth of fluorescent microbeads, a method using patterned elastic substrate was proposed to measure cell traction forces, in which the micropattern arrays fabricated on the surface of substrate was used as deformation markers. A micro-pad array with diameter of 3 µm and height of 0.8 µm was designed and fabricated on the polydimethylsiloxane substrate surface as the displacement markers. In the finite element simulation, external forces mimicking cell traction forces was applied at different locations on the substrate surface and the displacements field of the micro-pad array was obtained. Using the displacements field obtained by simulation, the traction force field was calculated through the traction force inversion algorithm, and the results were consistent with the input external forces in the simulation. The patterned elastic substrates were validated by mapping neonatal rat ventricular myocytes contraction forces. Both simulation and experiment demonstrate that the capacity of patterned elastic substrate for generating accurate cell contraction force maps, providing new research method for pathological study of myocardial diseases

Anisotropic vanadium dioxide sculptured thin films with superior thermochromic properties

VO2 (M) STF through reduction of V2O5 STF was prepared. The results illustrate that V2O5 STF can be successfully obtained by oblique angle thermal evaporation technique. After annealing at 550 degrees C/3 min, the V2O5 STF deposited at 856 can be easily transformed into VO2 STF with slanted columnar structure and superior thermochromic properties. After deposition SiO2 antireflective layer, T-lum of VO2 STF is enhanced 26% and Delta T-sol increases 60% compared with that of normal VO2 thin films. Due to the anisotropic microstructure of VO2 STF, angular selectivity transmission of VO2 STF is observed and the solar modulation ability is further improved from 7.2% to 8.7% when light is along columnar direction. Moreover, the phase transition temperature of VO2 STF can be depressed into 54.5 degrees C without doping. Considering the oblique incidence of sunlight on windows, VO2 STF is more beneficial for practical application as smart windows compared with normal homogenous VO2 thin films

Effect of Ag content and extrusion on the microstructure and mechanical properties of Mg–Ag alloys

Recently, the Mg–Ag binary alloy has gained much attention as an antibacterial biomaterial. However, the relationships between the extrusion parameters, microstructure, and mechanical properties of Mg–Ag alloys haven't been clearly established. Therefore, in this paper, the effects of silver (Ag) content (0, 3, 6 wt%) and extrusion (as cast, extrusion ratio (ER) 7.1 and 72.2) on the microstructure and mechanical properties of Mg–Ag alloys are systematically investigated. The results indicate that for the Mg–Ag alloys with the same extrusion ratio, as the Ag increased from 0 to 3 wt%, Mg4Ag and Mg54Ag17 precipitated, leading to significant precipitation strengthening and an increase in the yield strength by over 137%. As the Ag increased to 6 wt%, the yield strength increased by only ∼20%, attributable to Ag promoting dynamic recrystallization, resulting in less grain refinement, a slower amount increase and a smaller size reduction of the precipitate. For the Mg–Ag alloys with the same Ag content, as the extrusion ratio increased to 7.1, the yield strength increased significantly by over 37%, since the grain boundary strengthening and precipitation strengthening were significantly enhanced as the grains were refined, a large number of precipitates appeared, and their sizes significantly reduced. When the extrusion ratio increased to 72.2, the yield strength increased by only ∼10%, due to the weakening of both grain boundary strengthening and precipitation strengthening as the recrystallization further improved, leading to an increase in grain sizes, the redissolution of precipitates, and a lesser reduction in their sizes

Room-temperature sub-100 nm Néel-type skyrmions in non-stoichiometric van der Waals ferromagnet Fe3-x GaTe2 with ultrafast laser writability

Abstract Realizing room-temperature magnetic skyrmions in two-dimensional van der Waals ferromagnets offers unparalleled prospects for future spintronic applications. However, due to the intrinsic spin fluctuations that suppress atomic long-range magnetic order and the inherent inversion crystal symmetry that excludes the presence of the Dzyaloshinskii-Moriya interaction, achieving room-temperature skyrmions in 2D magnets remains a formidable challenge. In this study, we target room-temperature 2D magnet Fe3GaTe2 and unveil that the introduction of iron-deficient into this compound enables spatial inversion symmetry breaking, thus inducing a significant Dzyaloshinskii-Moriya interaction that brings about room-temperature Néel-type skyrmions with unprecedentedly small size. To further enhance the practical applications of this finding, we employ a homemade in-situ optical Lorentz transmission electron microscopy to demonstrate ultrafast writing of skyrmions in Fe3-x GaTe2 using a single femtosecond laser pulse. Our results manifest the Fe3-x GaTe2 as a promising building block for realizing skyrmion-based magneto-optical functionalities