Nanowerk April 8, 2023 An international team of researchers (Spain, Saudi Arabia, USA – University of Nevada) developed inexpensive benchtop plotters in combination with refillable writing pens and markers as a powerful route to print nanomaterial-based inks on paper substrates using inks of many different solution-processable nanomaterials. It is a robust, precise plotter and allowed printing pattern features with pitch separation as narrow as 80 μm. They illustrated printing van der Waals materials, organic semiconductors, hybrid perovskites and colloidal nanoparticles with a broad range of properties. The system was used to create several example applications such as an all-printed, paper-supported photodetector. […]
New textile unravels warmth-trapping secrets of polar bear fur
Science Daily April 10, 2023 There are evidence that polar-dwelling animals have evolved a different mechanism of thermoregulation by using optical polymer materials to achieve an on-body “greenhouse” effect. Researchers at UMass Amherst designed a bilayer textile to mimic these adaptations. They showed that two ultralightweight fabrics with complementary optical functions, a polypropylene visible-transparent insulator and a nylon visible-absorber–infrared-reflector coated with a conjugated polymer, performed the same putative function as polar bear hair and skin, respectively. While retaining familiar textile qualities, these layers suppressed dissipation of body heat and maximized radiative absorption of visible light. Under moderate illumination of 130 […]
A new type of photonic time crystal gives light a boost
Phys.org April 5, 2023 The synthesis of photonic time crystals materials and experimental observation of their physics remain very challenging because of the stringent requirement for uniform modulation of material properties in volumetric samples. An international team of researchers (Finland, Germany, USA – Stanford University) has extended the concept of photonic time crystals to two-dimensional metasurfaces. They demonstrated that time-varying metasurfaces not only preserve key physical properties of volumetric photonic time crystals despite their simpler topology but also host common momentum bandgaps shared by both surface and free-space electromagnetic waves. Based on a microwave metasurface design, they experimentally confirmed the […]
Physicists Have Successfully Generated Tiny Solar Flares in The Lab
Science Alert April 12, 2023 Solar observations detect energetic particles and hard X-rays but cannot reveal the generating mechanism because the particle acceleration happens at a scale smaller than the observation resolution. Thus, details of the cross-scale physics that explain the generation of energetic particles and hard X-rays remain a mystery. Researchers at Caltech set up a laboratory experiment toltage spike in braided magnetic flux ropes of a 2-eV plasma when the braid strand radius was choked down to be at the kinetic scale by either magnetohydrodynamic (MHD) kink or magnetic Rayleigh–Taylor instabilities. This sequence of hat simulates solar coronal […]
Robots predict human intention for faster builds
Science Daily April 5, 2023 To focus on enabling robots to proactively assist humans in assembly tasks by adapting to their preferred sequence of actions researchers at the University of Southern California proposed learning human preferences from demonstrations in a shorter, canonical task to predict user actions in the actual assembly task. The proposed system used the preference model learned from the canonical task as a prior and updates the model through interaction when predictions are inaccurate. They evaluated the proposed system in simulated assembly tasks and in a real-world human-robot assembly study and showed that both transferring the preference […]
Scientists discover a way Earth’s atmosphere cleans itself
Phys.org April 7, 2023 Hydroxyl radical (OH) is a key oxidant that triggers atmospheric oxidation chemistry in both gas and aqueous phases. The current understanding of its aqueous sources is mainly based on known bulk (photo) chemical processes, uptake from gaseous OH, or related to interfacial O3 and NO3 radical-driven chemistry. An international team of researchers (France, USA – UC Irvine, Israel) has provided experimental evidence that OH radicals are spontaneously produced at the air–water interface of aqueous droplets in the dark and the absence of known precursors, possibly due to the strong electric field that forms at such interfaces. […]
Tiny biobattery with potential 100-year shelf life runs on bacteria
Phys.org April 12, 2023 Controllable microbial electrocatalytic activity in a miniaturized microbial fuel cells (MFCs) with unlimited biodegradable energy resources would enable simple power generation in various environmental settings. However, the short shelf-life of living biocatalysts, few ways to activate the stored biocatalysts, and extremely low electrocatalytic capabilities render the miniature MFCs unsuitable for practical use. Researchers at State University of New York at Binghamton used heat-activated Bacillus subtilis spores as a dormant biocatalyst that could survive storage and rapidly germinate when exposed to special nutrients that are preloaded in the device. A microporous, graphene hydrogel allowed the adsorption of […]
Tiny movements, deep inside a battery
Nanowerk April 5, 2023 Researchers at Argonne National Laboratory demonstrated lithiation gradients and electrode assembly movement during electrochemical cycling of a Li-metal cell containing a Ni–Mn–Co layered oxide cathode (NMC811). During charge, deposition of Li+ ions from the cathode increased the Li foil thickness; during discharge, the thickness decreased as Li+ ions are stripped off the foil. The resulting periodic movement was observed through tracking of Bragg peaks from the ordered phases of the cathode and separator. In addition to this 3.6 μm/mAh displacement, continuous mossy Li build-up on the anode caused an irreversible drift of the assembly, which is […]
Top 10 Science and Technology Inventions for the Week of April 7, 2023
01. Absolute zero in the quantum computer: Formulation for the third law of thermodynamics 02. Can a solid be a superfluid? Engineering a novel supersolid state from layered 2D materials 03. Connecting distant silicon qubits for scaling up quantum computers 04. Imaging technique reveals electronic charges with single-atom resolution 05. “Spatial computing” enables flexible working memory 06. The modulation of a single-molecule electron source using light 07. Using quantum fluctuations to generate random numbers faster 08. Researchers develop novel nonwovens that are electrically conductive but thermally insulating 09. Revolutionary battery technology to boost EV range 10-fold or more 10. Scientists […]
Absolute zero in the quantum computer: Formulation for the third law of thermodynamics
Phys.org April 4, 2023 Nernst’s unattainability principle states that infinite resources are required to cool a system to absolute zero temperature. An international team of researchers (Japan, Austria, Sweden, France, Denmark, Switzerland, Ireland, Brazil, Germany) provided a framework for identifying the resources that enable the creation of pure quantum states. They showed that perfect cooling is possible with Landauer energy cost given infinite time or control complexity. However, optimal protocols required complex unitaries generated by an external work source. Restricting to unitaries that can be run solely via a heat engine, they derived a novel Carnot-Landauer limit, along with protocols […]