UTA engineer earns NSF CAREER grant to develop bioinspired, shape-morphing 3D materials
(University of Texas at Arlington) Kyungsuk Yum, an assistant professor in the Materials Science and Engineering Department has been awarded a five-year, $500,000 National Science Foundation Early Career Development, or CAREER, Program grant to design and develop bioinspired 3D materials with programmed shapes and motions. (Source: EurekAlert! - Biology)
Source: EurekAlert! - Biology - February 15, 2019 Category: Biology Source Type: news
Two-dimensional magnetic crystals and emergent heterostructure devices
Magnetism, originating from the moving charges and spin of elementary particles, has revolutionized important technologies such as data storage and biomedical imaging, and continues to bring forth new phenomena in emergent materials and reduced dimensions. The recently discovered two-dimensional (2D) magnetic van der Waals crystals provide ideal platforms for understanding 2D magnetism, the control of which has been fueling opportunities for atomically thin, flexible magneto-optic and magnetoelectric devices (such as magnetoresistive memories and spin field-effect transistors). The seamless integration of 2D magnets with d...
Source: ScienceNOW - February 14, 2019 Category: Science Authors: Gong, C., Zhang, X. Tags: Physics, Applied, Materials Science, Online Only review Source Type: news
Hyperbolic 3D architectures with 2D ceramics
Source: ScienceNOW - February 14, 2019 Category: Science Authors: Chhowalla, M., Jariwala, D. Tags: Materials Science perspective Source Type: news
The ultimate in thin-film magnetism
Source: ScienceNOW - February 14, 2019 Category: Science Authors: Osborne, I. S. Tags: Physics, Applied, Materials Science twis Source Type: news
Double-negative-index ceramic aerogels for thermal superinsulation
In this study, we designed and synthesized hyperbolic architectured ceramic aerogels with nanolayered double-pane walls with a negative Poisson’s ratio (–0.25) and a negative linear thermal expansion coefficient (–1.8 x 10–6 per °C). Our aerogels display robust mechanical and thermal stability and feature ultralow densities down to ~0.1 milligram per cubic centimeter, superelasticity up to 95%, and near-zero strength loss after sharp thermal shocks (275°C per second) or intense thermal stress at 1400°C, as well as ultralow thermal conductivity in vacuum [~2.4 milliwatts per meter-kelvin ...
Source: ScienceNOW - February 14, 2019 Category: Science Authors: Xu, X., Zhang, Q., Hao, M., Hu, Y., Lin, Z., Peng, L., Wang, T., Ren, X., Wang, C., Zhao, Z., Wan, C., Fei, H., Wang, L., Zhu, J., Sun, H., Chen, W., Du, T., Deng, B., Cheng, G. J., Shakir, I., Dames, C., Fisher, T. S., Zhang, X., Li, H., Huang, Y., Duan, Tags: Engineering, Materials Science reports Source Type: news
Chemically reversible isomerization of inorganic clusters
Structural transformations in molecules and solids have generally been studied in isolation, whereas intermediate systems have eluded characterization. We show that a pair of cadmium sulfide (CdS) cluster isomers provides an advantageous experimental platform to study isomerization in well-defined, atomically precise systems. The clusters coherently interconvert over an ~1–electron volt energy barrier with a 140–milli–electron volt shift in their excitonic energy gaps. There is a diffusionless, displacive reconfiguration of the inorganic core (solid-solid transformation) with first order (isomerization-li...
Source: ScienceNOW - February 14, 2019 Category: Science Authors: Williamson, C. B., Nevers, D. R., Nelson, A., Hadar, I., Banin, U., Hanrath, T., Robinson, R. D. Tags: Chemistry, Materials Science reports Source Type: news
Dynamic gating of infrared radiation in a textile
The human body absorbs and loses heat largely through infrared radiation centering around a wavelength of 10 micrometers. However, neither our skin nor the textiles that make up clothing are capable of dynamically controlling this optical channel for thermal management. By coating triacetate-cellulose bimorph fibers with a thin layer of carbon nanotubes, we effectively modulated the infrared radiation by more than 35% as the relative humidity of the underlying skin changed. Both experiments and modeling suggest that this dynamic infrared gating effect mainly arises from distance-dependent electromagnetic coupling between n...
Source: ScienceNOW - February 7, 2019 Category: Science Authors: Zhang, X. A., Yu, S., Xu, B., Li, M., Peng, Z., Wang, Y., Deng, S., Wu, X., Wu, Z., Ouyang, M., Wang, Y. Tags: Materials Science reports Source Type: news
Homogenized halides and alkali cation segregation in alloyed organic-inorganic perovskites
The role of the alkali metal cations in halide perovskite solar cells is not well understood. Using synchrotron-based nano–x-ray fluorescence and complementary measurements, we found that the halide distribution becomes homogenized upon addition of cesium iodide, either alone or with rubidium iodide, for substoichiometric, stoichiometric, and overstoichiometric preparations, where the lead halide is varied with respect to organic halide precursors. Halide homogenization coincides with long-lived charge carrier decays, spatially homogeneous carrier dynamics (as visualized by ultrafast microscopy), and improv...
Source: ScienceNOW - February 7, 2019 Category: Science Authors: Correa-Baena, J.-P., Luo, Y., Brenner, T. M., Snaider, J., Sun, S., Li, X., Jensen, M. A., Hartono, N. T. P., Nienhaus, L., Wieghold, S., Poindexter, J. R., Wang, S., Meng, Y. S., Wang, T., Lai, B., Holt, M. V., Cai, Z., Bawendi, M. G., Huang, L., Buonass Tags: Materials Science reports Source Type: news
Mechanoresponsive self-growing hydrogels inspired by muscle training
Living tissues, such as muscle, autonomously grow and remodel themselves to adapt to their surrounding mechanical environment through metabolic processes. By contrast, typical synthetic materials cannot grow and reconstruct their structures once formed. We propose a strategy for developing "self-growing" polymeric materials that respond to repetitive mechanical stress through an effective mechanochemical transduction. Robust double-network hydrogels provided with a sustained monomer supply undergo self-growth, and the materials are substantially strengthened under repetitive loading through a structural destructi...
Source: ScienceNOW - January 31, 2019 Category: Science Authors: Matsuda, T., Kawakami, R., Namba, R., Nakajima, T., Gong, J. P. Tags: Materials Science r-articles Source Type: news
Identification of site-specific isotopic labels by vibrational spectroscopy in the electron microscope
The identification of isotopic labels by conventional macroscopic techniques lacks spatial resolution and requires relatively large quantities of material for measurements. We recorded the vibrational spectra of an α amino acid, l-alanine, with damage-free "aloof" electron energy-loss spectroscopy in a scanning transmission electron microscope to directly resolve carbon-site–specific isotopic labels in real space with nanoscale spatial resolution. An isotopic red shift of 4.8 ± 0.4 milli–electron volts in C–O asymmetric stretching modes was observed for 13C-labeled l-alanine at the ...
Source: ScienceNOW - January 31, 2019 Category: Science Authors: Hachtel, J. A., Huang, J., Popovs, I., Jansone-Popova, S., Keum, J. K., Jakowski, J., Lovejoy, T. C., Dellby, N., Krivanek, O. L., Idrobo, J. C. Tags: Biochemistry, Materials Science reports Source Type: news
Integrated Device Design Critical to Rapid Medical IoT Development
Medical IoT holds the promise of vastly improved patient outcomes, along with the potential for an evolutionary step-change in the way healthcare is managed and delivered. Medical IoT devices will enable more rapid detection of disease, continuous remote monitoring of a patientâs condition, and far more targeted, effective treatment of conditions ranging from diabetes to cancer. All aspects of fundamental healthcare will be impacted: Prevention and wellness, chronic care, acute care, and post-acute care monitoring. As a consequence, the market for connected medical devices is estimated to grow from $20.6B...
Source: MDDI - January 29, 2019 Category: Medical Devices Authors: James Clements Tags: Electronics Source Type: news
Design and control of gas diffusion process in a nanoporous soft crystal
Design of the gas-diffusion process in a porous material is challenging because a contracted pore aperture is a prerequisite, whereas the channel traffic of guest molecules is regulated by the flexible and dynamic motions of nanochannels. Here, we present the rational design of a diffusion-regulatory system in a porous coordination polymer (PCP) in which flip-flop molecular motions within the framework structure provide kinetic gate functions that enable efficient gas separation and storage. The PCP shows substantial temperature-responsive adsorption in which the adsorbate molecules are differentiated by each gate-admissio...
Source: ScienceNOW - January 24, 2019 Category: Science Authors: Gu, C., Hosono, N., Zheng, J.-J., Sato, Y., Kusaka, S., Sakaki, S., Kitagawa, S. Tags: Chemistry, Materials Science reports Source Type: news
A hydrated crystalline calcium carbonate phase: Calcium carbonate hemihydrate
As one of the most abundant materials in the world, calcium carbonate, CaCO3, is the main constituent of the skeletons and shells of various marine organisms. It is used in the cement industry and plays a crucial role in the global carbon cycle and formation of sedimentary rocks. For more than a century, only three polymorphs of pure CaCO3—calcite, aragonite, and vaterite—were known to exist at ambient conditions, as well as two hydrated crystal phases, monohydrocalcite (CaCO3·1H2O) and ikaite (CaCO3·6H2O). While investigating the role of magnesium ions in crystallization pathways of amorphous cal...
Source: ScienceNOW - January 24, 2019 Category: Science Authors: Zou, Z., Habraken, W. J. E. M., Matveeva, G., Jensen, A. C. S., Bertinetti, L., Hood, M. A., Sun, C.-y., Gilbert, P. U. P. A., Polishchuk, I., Pokroy, B., Mahamid, J., Politi, Y., Weiner, S., Werner, P., Bette, S., Dinnebier, R., Kolb, U., Zolotoyabko, E. Tags: Chemistry, Materials Science reports Source Type: news
Nematic-to-columnar mesophase transition by in situ supramolecular polymerization
We report that supramolecular polymerization of a disk-shaped chiral monomer in nematic liquid crystals comprising rod-shaped molecules results in order-increasing mesophase transition into a single mesophase with a core-shell columnar geometry. This liquid crystalline material responds quickly to an applied electric field, resulting in unidirectional columnar ordering. Moreover, it can be modularly customized to be optoelectrically responsive simply by using a photoisomerizable rod-shaped module. The modular strategy allows for cooperative integration of different functions into elaborate dynamic architectures. (Source: ScienceNOW)
Source: ScienceNOW - January 10, 2019 Category: Science Authors: Yano, K., Itoh, Y., Araoka, F., Watanabe, G., Hikima, T., Aida, T. Tags: Chemistry, Materials Science reports Source Type: news
Complete steric exclusion of ions and proton transport through confined monolayer water
We report capillaries made by effectively extracting one atomic plane from bulk crystals, which leaves a two-dimensional slit of a few angstroms in height. Water moves through these capillaries with little resistance, whereas no permeation could be detected even for such small ions as Na+ and Cl–. Only protons (H+) can diffuse through monolayer water inside the capillaries. These observations improve our understanding of molecular transport at the atomic scale. (Source: ScienceNOW)
Source: ScienceNOW - January 10, 2019 Category: Science Authors: Gopinadhan, K., Hu, S., Esfandiar, A., Lozada-Hidalgo, M., Wang, F. C., Yang, Q., Tyurnina, A. V., Keerthi, A., Radha, B., Geim, A. K. Tags: Materials Science, Physics reports Source Type: news
Mating disks and rods into an ordered phase
Source: ScienceNOW - January 10, 2019 Category: Science Authors: Lavine, M. S. Tags: Chemistry, Materials Science twis Source Type: news
Single-component quasicrystalline nanocrystal superlattices through flexible polygon tiling rule
Quasicrystalline superlattices (QC-SLs) generated from single-component colloidal building blocks have been predicted by computer simulations but are challenging to reproduce experimentally. We discovered that 10-fold QC-SLs could self-organize from truncated tetrahedral quantum dots with anisotropic patchiness. Transmission electron microscopy and tomography measurements allow structural reconstruction of the QC-SL from the nanoscale packing to the atomic-scale orientation alignments. The unique QC order leads to a tiling concept, the "flexible polygon tiling rule," that replicates the experimental observations....
Source: ScienceNOW - December 20, 2018 Category: Science Authors: Nagaoka, Y., Zhu, H., Eggert, D., Chen, O. Tags: Chemistry, Materials Science reports Source Type: news
A linear cobalt(II) complex with maximal orbital angular momentum from a non-Aufbau ground state
Orbital angular momentum is a prerequisite for magnetic anisotropy, although in transition metal complexes it is typically quenched by the ligand field. By reducing the basicity of the carbon donor atoms in a pair of alkyl ligands, we synthesized a cobalt(II) dialkyl complex, Co(C(SiMe2ONaph)3)2 (where Me is methyl and Naph is a naphthyl group), wherein the ligand field is sufficiently weak that interelectron repulsion and spin-orbit coupling play a dominant role in determining the electronic ground state. Assignment of a non-Aufbau (dx2–y2, dxy)3(dxz, dyz)3(dz2)1 electron configuration is supported by dc magnetic su...
Source: ScienceNOW - December 20, 2018 Category: Science Authors: Bunting, P. C., Atanasov, M., Damgaard-Moller, E., Perfetti, M., Crassee, I., Orlita, M., Overgaard, J., van Slageren, J., Neese, F., Long, J. R. Tags: Chemistry, Materials Science, Online Only r-articles Source Type: news
Bioelectronics that vanish in the body
Source: ScienceNOW - December 13, 2018 Category: Science Authors: Service, R. F. Tags: Biotechnology, Materials Science In Depth Source Type: news
Printing nanomaterials in shrinking gels
Source: ScienceNOW - December 13, 2018 Category: Science Authors: Long, T. E., Williams, C. B. Tags: Materials Science perspective Source Type: news
Revealing hidden spin-momentum locking in a high-temperature cuprate superconductor
Cuprate superconductors have long been thought of as having strong electronic correlations but negligible spin-orbit coupling. Using spin- and angle-resolved photoemission spectroscopy, we discovered that one of the most studied cuprate superconductors, Bi2212, has a nontrivial spin texture with a spin-momentum locking that circles the Brillouin zone center and a spin-layer locking that allows states of opposite spin to be localized in different parts of the unit cell. Our findings pose challenges for the vast majority of models of cuprates, such as the Hubbard model and its variants, where spin-orbit interaction has been ...
Source: ScienceNOW - December 13, 2018 Category: Science Authors: Gotlieb, K., Lin, C.-Y., Serbyn, M., Zhang, W., Smallwood, C. L., Jozwiak, C., Eisaki, H., Hussain, Z., Vishwanath, A., Lanzara, A. Tags: Materials Science, Physics r-articles Source Type: news
Ultralow-loading platinum-cobalt fuel cell catalysts derived from imidazolate frameworks
Achieving high catalytic performance with the lowest possible amount of platinum is critical for fuel cell cost reduction. Here we describe a method of preparing highly active yet stable electrocatalysts containing ultralow-loading platinum content by using cobalt or bimetallic cobalt and zinc zeolitic imidazolate frameworks as precursors. Synergistic catalysis between strained platinum-cobalt core-shell nanoparticles over a platinum-group metal (PGM)–free catalytic substrate led to excellent fuel cell performance under 1 atmosphere of O2 or air at both high-voltage and high-current domains. Two catalysts achieved ox...
Source: ScienceNOW - December 13, 2018 Category: Science Authors: Chong, L., Wen, J., Kubal, J., Sen, F. G., Zou, J., Greeley, J., Chan, M., Barkholtz, H., Ding, W., Liu, D.-J. Tags: Chemistry, Materials Science reports Source Type: news
3D nanofabrication by volumetric deposition and controlled shrinkage of patterned scaffolds
We present a strategy for the direct assembly of 3D nanomaterials consisting of metals, semiconductors, and biomolecules arranged in virtually any 3D geometry. We used hydrogels as scaffolds for volumetric deposition of materials at defined points in space. We then optically patterned these scaffolds in three dimensions, attached one or more functional materials, and then shrank and dehydrated them in a controlled way to achieve nanoscale feature sizes in a solid substrate. We demonstrate that our process, Implosion Fabrication (ImpFab), can directly write highly conductive, 3D silver nanostructures within an acrylic scaff...
Source: ScienceNOW - December 13, 2018 Category: Science Authors: Oran, D., Rodriques, S. G., Gao, R., Asano, S., Skylar-Scott, M. A., Chen, F., Tillberg, P. W., Marblestone, A. H., Boyden, E. S. Tags: Materials Science, Physics reports Source Type: news
Room-temperature cycling of metal fluoride electrodes: Liquid electrolytes for high-energy fluoride ion cells
We report a liquid fluoride ion–conducting electrolyte with high ionic conductivity, wide operating voltage, and robust chemical stability based on dry tetraalkylammonium fluoride salts in ether solvents. Pairing this liquid electrolyte with a copper–lanthanum trifluoride (Cu@LaF3) core-shell cathode, we demonstrate reversible fluorination and defluorination reactions in a fluoride ion electrochemical cell cycled at room temperature. Fluoride ion–mediated electrochemistry offers a pathway toward developing capacities beyond that of lithium ion technology. (Source: ScienceNOW)
Source: ScienceNOW - December 6, 2018 Category: Science Authors: Davis, V. K., Bates, C. M., Omichi, K., Savoie, B. M., Momcilovic, N., Xu, Q., Wolf, W. J., Webb, M. A., Billings, K. J., Chou, N. H., Alayoglu, S., McKenney, R. K., Darolles, I. M., Nair, N. G., Hightower, A., Rosenberg, D., Ahmed, M., Brooks, C. J., Mil Tags: Chemistry, Materials Science reports Source Type: news
Semiconducting polymer blends that exhibit stable charge transport at high temperatures
We report a general strategy to make thermally stable high-temperature semiconducting polymer blends, composed of interpenetrating semicrystalline conjugated polymers and high glass-transition temperature insulating matrices. When properly engineered, such polymer blends display a temperature-insensitive charge transport behavior with hole mobility exceeding 2.0 cm2/V·s across a wide temperature range from room temperature up to 220°C in thin-film transistors. (Source: ScienceNOW)
Source: ScienceNOW - December 6, 2018 Category: Science Authors: Gumyusenge, A., Tran, D. T., Luo, X., Pitch, G. M., Zhao, Y., Jenkins, K. A., Dunn, T. J., Ayzner, A. L., Savoie, B. M., Mei, J. Tags: Chemistry, Materials Science reports Source Type: news
Building two-dimensional materials one row at a time: Avoiding the nucleation barrier
Assembly of two-dimensional (2D) molecular arrays on surfaces produces a wide range of architectural motifs exhibiting unique properties, but little attention has been given to the mechanism by which they nucleate. Using peptides selected for their binding affinity to molybdenum disulfide, we investigated nucleation of 2D arrays by molecularly resolved in situ atomic force microscopy and compared our results to molecular dynamics simulations. The arrays assembled one row at a time, and the nuclei were ordered from the earliest stages and formed without a free energy barrier or a critical size. The results verify long-stand...
Source: ScienceNOW - December 6, 2018 Category: Science Authors: Chen, J., Zhu, E., Liu, J., Zhang, S., Lin, Z., Duan, X., Heinz, H., Huang, Y., De Yoreo, J. J. Tags: Chemistry, Materials Science, Physics reports Source Type: news
Pushing 3D Printing Forward
Researchers and students have demonstrated that inks can be used instead of thermoplastic filaments to 3D print functional biomedical devices. Michael McAlpine, Benjamin Mayhugh Associate Professor of Mechanical Engineering at the University of Minnesota, described such advances in the ESC Minneapolis keynote, â3D Printing Functional Materials & Devices.â A lot of the inks McAlpineâs group uses are nanometer-scale particle inks printed at a line-width scale of 10 microns and above for printing devices at the macro level. They have developed software as well as a hig...
Source: MDDI - December 4, 2018 Category: Medical Devices Authors: Daphne Allen Tags: MD & M Minneapolis 3-D Printing Source Type: news
A research facility to drive forward technological progress
The European Spallation Source (ESS) will be the world's most powerful source of neutrons, a key tool in advancing materials science and technological progress. An EU-funded project has supported the development of ESS, which could lead to scientific breakthroughs that improve our quality of life. (Source: EUROPA - Research Information Centre)
Source: EUROPA - Research Information Centre - November 30, 2018 Category: Research Source Type: news
How Can Nanotechnologies Aid Implantable Drug-Delivery Systems?
Implantable technologies have come a long way over the years, and advancements in micro and nanotechnologies have helped device developers continue to push the envelope even further. Within the realm of drug delivery, advances in nanotechnologies have consistently improved patient outcomes by enabling sustained drug delivery to help treat chronic conditions. These scalable technologies have even offered localized drug delivery that can further improve bioavailability. While many of these technologies offer a variety of opportunities, weâre still eagerly awaiting to see the impact of these advancements onc...
Source: MDDI - November 29, 2018 Category: Medical Devices Authors: Kristopher Sturgis Tags: BIOMEDevice San Jose Implants Source Type: news