Nanowerk January 16, 2023 Ultrathin optical metasurfaces have been recently explored to process large images in real time, in particular for edge detection. They can be tailored to solve complex mathematical problems in the analogue domain, although these efforts have so far been limited to guided-wave systems and bulky set-ups. An international team of researchers (the Netherlands, USA – University of Pennsylvania, City University of New York) developed an ultrathin Si metasurface-based platform for analogue computing that was able to solve Fredholm integral equations of the second kind using free-space visible radiation. A Si-based metagrating was inverse-designed to implement the […]
Nanoparticles make it easier to turn light into solvated electrons
Nanowerk January 17, 2023 Solvated electrons are powerful reducing agents capable of driving some of the most energetically expensive reduction reactions. It has been proposed that solvated electrons, which are powerful reducing agents, could be produced by photoexcitation of roughened metal electrodes, but no study has demonstrated a clear mechanism for their generation. A team of researchers in the US (Rice University, Stanford University, UT Austin) has shown that plasmons create solvated electrons in water. They showed that the yield of solvated electrons in water was increased more than 10 times for nanoparticle-decorated electrodes compared to smooth silver electrodes. Based […]
Now on the molecular scale: Electric motors
Science Daily January 11, 2023 An international team of researchers (USA – Northwestern University, Caltech, University of Maine, Switzerland, Italy, UK, Australia) has developed an electric molecular motor that works in solution using chemistry to effectively drive a molecular motor, much like a macroscopic motor. The motor was easy to make, operated quickly and did not produce any waste products. The 2 nanometers wide molecular motor was the first to be produced en masse in abundance. They focused on catenanes held together by powerful mechanical bonds, so the components could move freely relative to each other without falling apart. According […]
Organic semiconductors curl up in the dark
Nanowerk January 17, 2023 Organic semiconductors have the potential to replace their silicon predecessors in many applications. However, the manufacturing processes of solar cells that achieve such efficiencies are not yet compatible with mass production. An international team of researchers (Denmark, Germany) used roll-to-roll methos to print the organic semiconductor (poly(3-hexylthiophene) or P3HT), used for flexible solar cells, and organic electronics directly on a polymer film. In solution without illumination or under red light, the polymer chains quickly aggregated and formed ordered domains. When illuminated under green or blue light, the more rigid polymer chains, excited by the light, were […]
Political Interference: White House Launches Framework to Protect Scientific Integrity
Global Biodefense January 13, 2023 The White House Office of Science and Technology Policy (OSTP) released the Framework for Federal Scientific Integrity Policy and Practice. It builds on the assessment of federal scientific integrity policies and practices described in the January 2022 report. The goal of the Framework is to assist agencies across the Federal Government as they take next steps together to strengthen, implement, and institutionalize scientific integrity policy, practice, and culture. It requires all agencies to designate a scientific integrity official, and agencies that fund, conduct, or oversee research to designate a chief science officer, and it establishes […]
Preventing vehicle crashes by learning from insects
Science Daily January 17, 2023 For detecting a potential collision at night to alert the driver or, maneuvering system of an autonomous vehicle, current technologies utilize resource draining and expensive solutions such as LiDAR or image sensors coupled with extensive software running sophisticated algorithms. In contrast, insects perform the same task of collision detection with frugal neural resources. Researchers at Pennsylvania State University have shown that insect-inspired collision detection algorithms, when implemented in conjunction with in-sensor processing and enabled by innovative optoelectronic integrated circuits based on atomically thin and photosensitive memtransistor technology, can greatly simplify collision detection at night. The […]
Researchers create an optical tractor beam that pulls macroscopic objects
Science Daily January 11, 2023 In recent ten years, optical pulling of micro-nano objects have been fully demonstrated. However, optical pulling of a macroscopic object is challenging. Researchers in China have demonstrated laser pulling of a macroscopic object in rarefied gas. The pulling force was originated from the Kundsen force when a gauss laser beam irradiates a macroscopic structure composed of the absorptive bulk cross-linked graphene material and a SiO2 layer. A torsional pendulum device qualitatively presented the laser pulling phenomenon. A gravity pendulum device was used to further measure the pulling force that is more than three orders of […]
Researchers develop fluidic memristor with diverse neuromorphic functions
Nanowerk January 13, 2023 Mimicking the structure of human brain could lead to the development of next-generation neuromorphic devices. Focusing on different aspects of neuromorphic engineering, researchers in China created nanofluidic devices consisting of nanometer-thick two-dimensional slits filled with a salt solution, and a nanofluidic ionic memristor based on confined polyelectrolyte-ion interactions. They demonstrated neuromorphic functions with a polyelectrolyte-confined fluidic memristor (PFM), resulting in ion memory effects emulating various electric pulse patterns with ultralow energy consumption. PFM is versatile and easily interfaces with biological systems, paving a way to building neuromorphic devices with advanced functions by introducing rich chemical designs…read […]
Researchers gain deeper understanding of mechanism behind superconductors
Phys.org January 17, 2023 High-temperature superconducting cuprates respond to doping with a dome-like dependence of their critical temperature (Tc). But the family-specific maximum Tc can be surpassed by application of pressure. Researchers in Germany investigated the phenomenon with high-pressure anvil cell NMR and measured the charge content at planar Cu and O, and with it the doping of the CuO2. They found that pressure increases the overall hole doping but when it enhances Tc above what can be achieved by doping, pressure leads to a hole redistribution favoring planar O. This is similar to the observation that the family-specific maximum […]
A year on, we now know why the Tongan eruption was so violent. It’s a wake-up call to watch other submarine volcanoes
Phys.org January 13, 2023 An international team of researchers (Tonga, New Zealand) studied the texture and chemistry of the erupted particles to find clues about the event’s violence. Isotopic “fingerprinting” showed at least three different magma sources were involved. Two magma bodies were older and resident in the middle of the Earth’s crust, the younger one joined shortly before the eruption. The mingling of magmas caused a strong reaction, driving water and other “volatile elements” out of solution and into gas. This created bubbles and an expanding magma foam, pushing the magma out vigorously at the onset of eruption. The […]