Phys.org December 17, 2024 The synergistic integration of all the components for efficient light harvesting, cascade electron transfer, and efficient biocatalytic reactions presents a formidable challenge. Researchers in the UK described the bottom-up construction of a visible-light-driven chemical–biological hybrid nanoreactor with augmented photocatalytic efficiency by anchoring an α-carboxysome shell encasing on the surface of a hydrogen-bonded organic molecular crystal, a microporous α-polymorph of tetra(4′-carboxyphenyl)pyrene (TBAP-α). Within this hybrid photobiocatalyst, TBAP-α functioned as an antenna for visible-light absorption and exciton generation, supplying electrons for hydrogen production by H–S in aqueous solutions. This coordination allowed the hybrid nanoreactor to execute hydrogen evolution […]
MIT engineers grow “high-rise” 3D chips
MIT News December 18, 2024 Although monolithic 3D (M3D) integration schemes show promise, the seamless connection of single-crystalline semiconductors without intervening wafers has yet to be demonstrated. An international team of researchers (USA – MIT, Korea) present a method for growing single-crystalline channel materials, specifically composed of transition metal dichalcogenides, on amorphous and polycrystalline surfaces at temperatures low enough to preserve the underlying electronic components. They demonstrated the seamless monolithic integration of vertical single-crystalline logic transistor arrays leading to the development of vertical CMOS arrays composed of grown single-crystalline channels. According to researchers their work provides opportunities for M3D integration […]
Model suggests Earth’s subsurface may hold up to 5.6 × 10⁶ million metric tons of natural hydrogen
Phys.org December 16, 2024 Geologic hydrogen could be a low-carbon primary energy resource; however, the magnitude of Earth’s subsurface hydrogen has not yet been assessed. Researchers at the US Geological Survey combined information from geologic analogs to construct a mass balance model to predict resource potential. Stochastic model results predicted a wide range of values for the potential in-place hydrogen resource with the most probable value of ~5.6 × 106 Mt. Although most of this hydrogen was likely to be impractical to recover, a small fraction (e.g., 1 × 105 Mt) would supply the projected hydrogen needed to reach net-zero […]
New method aids in predicting where next big quake will start
Phys.org December 12, 2024 An international team of researchers (USA – UC River Side, Japan, New Zealand) observed and further exhumed curved slickenlines on fault planes associated with paleo-surface rupture of the Alpine Fault in New Zealand’s continental transform plate boundary. Rupture modeling indicated that the geometry of such curvature provided a record of past earthquake rupture directions. They studied three sites that spanned a region known to variably halt or allow passage of past earthquakes to contribute rupture direction constraints to the fault’s paleoseismic record. In two sites they observed both convex-up and convex-down curved slickenlines on and adjacent […]
New polymer ramps up quest for better data storage
Nanowerk December 18, 2024 The storage medium must be modifiable on the nanoscale. While polymers are promising storage media, they face challenges with synthesis, erasing temperatures, and stability. Researchers in Australia developed a low-cost and robust polymer system that allows repeated writing, reading and erasing. It provided a network of S─S bonds that could be broken and re-formed repeatedly. They leveraged this property to encode information, and thermal S─S metathesis and polymer re-flow to erase. This control enabled data encoding not just as a function of the presence or absence of an indent, but also indentation depth. It increased the […]
Researchers develop power-free color-changing strain sensor
Nanowerk December 16, 2024 An international team of researchers (Republic of Korea, Viet Nam) developed a concept of a mechanochromic strain sensor based on magnetic field self-assembled amorphous photonic arrays (APAs) of magnetoplasmonic Ag@Fe3O4 core–shell nanoparticles. The nanoparticles had tunable color spans and fully reversible mechanochromic shift when triggered by stretching or deformation events. In particular, the designed sensors exhibit dynamic color-switching covering various range of reflectance shifts in the visible wavelength region. The most apparent blue-to-red color shift was observed with 176 nm nanoparticles. They investigated the role of surface plasmon resonance coupling in producing the mechanochromic effect. The […]
Scientists develop material with almost perfect water repellency
Phys.org December 12, 2024 While the accessible pores render an enormous variety of functionalities to the bulk of metal–organic frameworks (MOFs), the outer surfaces exposed by these crystalline materials also offer unique characteristics not available when using conventional substrates. An international team of researchers (Germany, India) fabricated superhydrophobic substrates with static water contact angles over 160° by grafting hydrocarbon chains to well-defined MOF thin films (SURMOFs) prepared using layer-by-layer methods. A detailed theoretical modelling of the hydrocarbon chains grafted on the outer SURMOF surface with well-defined spacing between anchoring points revealed that the grafted hydrocarbon chains behaved similarly to polymer […]
Sea sponge-inspired microlenses offer new possibilities in optics
Phys.org December 16, 2024 Conventional methods used to produce these microparticle components frequently offer limited control of their structural properties or require low-throughput nanofabrication of more complex structures. An international team of researchers (USA – University of Rochester, University of Colorado, the Netherlands) used a synthetic biology approach to produce environmentally friendly, living microlenses with tunable structural properties. They engineered Escherichia coli bacteria to display the silica biomineralization enzyme silicate from aquatic sea sponges which could self-assemble a shell of polysilicate “bioglass” around themselves. The bacteria could focus light into intense nanojets that were nearly an order of magnitude brighter […]
Simulation sheds light on Earth’s magnetic field generation while advancing neuromorphic computing
Phys.org December 16, 2024 An international team of researchers (USA -Sandia National Laboratory, Germany, France) implemented a molecular-spin dynamics methodology to accurately resolve, across large regions of phase-space, structural/magnetic transitions, and elastic/transport properties for iron to reconcile different theories of geodynamo operation, augmenting decades of deep experimental investigation. Dynamic compression of iron to Earth-core conditions is one of the few ways to gather important elastic and transport properties needed to uncover key mechanisms surrounding the geodynamo effect. The framework enabled an accurate resolution of the phase-transition kinetics and Earth-core elastic properties, as highlighted by compressional wave velocity and adiabatic bulk […]
Tiny chips promise swift disease diagnosis from a single breath
Phys/org December 16, 2024 Field-effect transistor (FET)-based electronic biosensing platforms are particularly attractive due to their sensitivity, fast turn-around time, potential for parallel detection of multiple pathogens, and compatibility with semiconductor manufacturing. However, scalability multiplexed biofunctionalization, nanoscale precision for immobilizing different types of pathogen-specific bioreceptors, are unmet. An international team of researchers (USA – New York University, SUNY Downstate Health Sciences University, industry, Italy) proposed a paradigm shift in FET biofunctionalization using thermal scanning probe lithography (tSPL) with a thermochemically sensitive polymer which could be spin-coated on fully fabricated FET chips, making this approach applicable to any FET sensor material […]