MRS Communications最新文献

Abstract

Metasurfaces can replace bulk optical components in a more compact form factor in applications including communication systems, sensors, and manufacturing technology. However, their design and fabrication is challenging due to competing demands of selecting meta-atoms that simultaneously provide the required amplitude and phase modulation while being robust to fabrication errors. Here, we develop two design heuristics to assist with the down-selection of meta-atoms into sensitivity-informed libraries, based on either selecting meta-atoms with minimal sensitivity or minimizing the relative sensitivities between meta-atoms. We evaluate both methods on a polarization-dependent phase mask and compare the resulting phase and intensity errors.

Graphical Abstract

Inorganic nanoparticles are a critical component in a broad range of applications spanning catalysis, sensing, optics, and electronics. The nucleation and growth mechanisms involved during their synthesis are known to be crucial for controlling their final performance. Macromolecules can display sequence definition, inherent chirality, metal ion targeting moieties, and can also form self-assemblies, affording them the ability to not only stabilize but also precisely control the synthesis and organization of nanoparticles for an intended application. Herein, we report the recent trends in inorganic nanoparticle synthesis mediated by peptides, peptoids, DNA, other biopolymers, and synthetic polymers. Important design parameters and future trends are also discussed.

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2-D transition metal-chalcogenides (TMCs) are lucrative as frequency selective absorbers (FSAs) because of strong electronic polarization and enhanced dielectric loss. In the present work we have developed inks made of 2-D TMCs such as NiSe₂, CoSe₂ and used them to develop metastructures having high reflection loss. The structures have conductivity peaks depending on concentration of the 2D structure in the paint. It is observed that the absorption bandwidth and frequency seem to depend on the composition of 2D TMC along with the structures made. This provides an additional method to modulate the properties of FSA.

Graphical Abstract

Barium titanate (BTO) is a ferroelectric perovskite used in electronics and energy storage systems because of its high dielectric constant. Decreasing the BTO particle size was shown to increase the dielectric constant of the perovskite, which is an intriguing but contested result. We investigated this result by fabricating silicone-matrix nanocomposite specimens containing BTO particles of decreasing diameter. Furthermore, density functional theory modeling was used to understand the interactions at the BTO particle surface. Combining results from experiments and modeling indicated that polymer type, particle surface interactions, and particle surface structure can influence the dielectric properties of polymer-matrix nanocomposites containing BTO.

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In this work, the functionalization of SnO₂ nanowires with grafted hydroxyl (OH) groups was introduced by changing the post-synthetic treatment and by growth in a vapor phase. Besides, the present paper describes two types of growth methods: (i) the vapor–solid one with post-synthesis treatment under NaOH solutions with different pH, and (ii) the direct growth using the vapor–liquid–solid one under water vapor. Structural characterizations demonstrated that OH groups were successfully anchored. Notably, band gap changes in the presence of OH groups are revealed. This kind of surface state engineering precisely opens new avenues of SnO₂ nanowire applications in sensors and semiconductor uses.

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This article reviews the recent progress in fabricating microfluidic devices and soft robots using direct ink writing (DIW) three-dimensional (3D) printing with silicone elastomers. Additive manufacturing, especially 3D printing, has become an alternative method to traditional soft lithography for producing microchannels, establishing a new standard in the field of microfluidics. This approach offers unprecedented opportunities for digital control, automation, and the elimination of manual assembly. Among different 3D printing technologies, DIW 3D printing facilitates the accurate deposition of liquid silicone precursors on various substrates in the air or liquid media, enabling the fabrication of microfluidic structures using a one-part room-temperature-vulcanizing (RTV) silicone sealant and two-part addition-curing silicone elastomers. The effectiveness of DIW 3D printing is demonstrated through (1) creating microchannels on various substrates, (2) printing interconnected, multilayer microchannels without the need for sacrificial support materials or extensive post-processing steps, and (3) integrating electronic components into microchannels during the printing process. In this article, overviews of the fabrication of microfluidic devices using 3D printing are provided first, followed by a discussion of different criteria and approaches for DIW 3D printing of silicone-based elastomeric structures in open-air and embedded media. Next, the structure–property relations of silicone-based microfluidic devices are discussed. Then, examples of DIW-fabricated silicone microfluidic devices and soft robotics are showcased, highlighting the unique benefits and opportunities of the methods. Finally, current challenges and future directions in DIW 3D printing of microfluidic systems are discussed.

Graphical Abstract

In the presence of ethylenediaminetetraacetic acid (EDTA), a straightforward hydrothermal method was conceptualized for the purpose of controlling the size and form of the zircon-type tetragonal phase of LaVO₄:Eu nanostructures. Nanorods and nanosheaves have been selectively obtained by tuning the pH value. In particular, LaVO₄:Eu nanorods covered by EDTA molecules are soluble in water. In addition, research on photoluminescence has demonstrated that Eu³⁺-doped LaVO₄ nanorods exhibit significant red emission when exposed to ultraviolet light. This phenomenon has the potential to be utilized in a variety of disciplines, including visual display, catalysis, and biological imaging.

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Abstract

We develop a materials informatics workflow to build an interpretable surrogate model for micromagnetic simulations. Our goal is to predict the energy barrier of a moving isolated skyrmion in rare-earth-free (hbox {Mn}_4)N. Our approach integrates adaptive learning with post hoc model explanation and symbolic regression methods. We discuss an unexplored acquisition function (information condensing active learning) within the adaptive learning loop and compare it with the known standard deviation function for efficient navigation of the search space. Model-agnostic post hoc explanation techniques then uncover trends learned by the trained model, which we then leverage to constrain the expressions used for symbolic regression.

Graphical abstract

The cobalt-promoted MoS₂ microspheres have been synthesized by hydrothermal methods using sodium molybdate precursors. Scanning electron microscopy indicates that spherical shape morphology and cobalt atoms are detected at MoS₂ edges corresponding to (101)-plane as revealed by Cs-corrected transmission electron microscopy. The magnetic states were measured by magnetization curves obtaining a 0.044 emu/g due to paramagnetic contribution. Furthermore, the electronic structure from the density of states for 2H-MoS₂ with and without cobalt at the (101) edge plane possesses a magnetic property with a value of 0.16 μ_B attributed to broken symmetry.

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