Lifeboat Foundation

Berkeley Lab engineers have developed an all-season smart roof coating that keeps homes warm during the winter and cool during the summer without consuming natural gas or electricity. The all-season roof coating automatically switches from keeping you cool to warm, depending on outdoor air temperature.

The problem with many cool-roof systems currently on the market is that they continue to radiate heat in the winter, which drives up heating costs, explained Junqiao Wu, a faculty scientist who led the study. “Our new material – called a temperature-adaptive radiative coating (TARC) – can enable energy savings by automatically turning off the radiative cooling in the winter, overcoming the problem of overcooling,” he said.

The key to the technology is a strange compound called vanadium dioxide (VO2). In 2017, Wu and his research team discovered that electrons in vanadium dioxide behave like metal to electricity but an insulator to heat. Below about 67 degrees Celsius, vanadium dioxide is also transparent to thermal-infrared light. But once vanadium dioxide reaches 67 degrees Celsius, the material switches to a metal state, becoming absorptive of thermal-infrared light. This ability to switch from one phase to another – in this case, from an insulator to metal – is characteristic of what’s known as a phase-change material.

The model describing a material where order doesn’t disappear as heat is applied also has implications for our understanding of the early universe.

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Efficient electrocatalysts, which are needed for the production of green hydrogen, for example, are hidden in materials composed of five or more elements. A team from Ruhr-Universität Bochum (RUB) and the University of Copenhagen has developed an efficient method for identifying promising candidates in the myriad of possible materials. To this end, the researchers combined experiments and simulation.

They published their report in the journal Advanced Energy Materials (“Unravelling Composition–Activity–Stability Trends in High Entropy Alloy Electrocatalysts by Using a Data-Guided Combinatorial Synthesis Strategy and Computational Modeling”).

A view of the sputtering machine used to produce the material library counters. (Image: Christian Nielinger)

A team of physicists from the Massachusetts Institute of Technology (MIT) has discovered a hybrid particle that could pave the way for smaller and faster electronic devices in the future.

The hybrid particle, which was found to be a mashup of an electron and a phonon (a quasiparticle formed by vibrating atoms in a material), was detected in a strange, two-dimensional magnetic substance.

Probably the most intriguing aspect of the discovery, however, is that when the scientists measured the force between the electron and phonon, they saw that the glue, or bond, was 10 times stronger than what had previously been estimated for other known electron-phonon hybrids, according to the study which has been published in the journal Nature Communications.

Circa 2020

Harnessing the destructive potential of force and rotation, cutting tools like saws, drills, and angle grinders can obliterate the superlative properties that materials work so hard to perfect. And even when materials are designed to work against the power of these tools, the materials still often fail.

Continue reading “Bio-inspired ceramic–metal composite stands its ground against cutting tools” »

Circa 2014

(2014). Current-Activated, Pressure-Assisted Infiltration: A Novel, Versatile Route for Producing Interpenetrating Ceramic–Metal Composites. Materials Research Letters: Vol. 2, No. 3, pp. 124–130.

Scientists have found a new “strange metal” that behaves in ways they can’t quite understand.

But the discovery could be key to finding out an explanation for a phenomenon that has troubles researchers for decades.

Most materials, such as copper and silver, behave in predictable and well understood ways, and scientists understand how their electrical conductance changes when they are heated or cooled.

Current night vision (NV) devices are bulky and heavy, resulting in a significant torque on the wearer’s neck. This torque greatly limits the wearer’s agility and often leads to chronic injury over prolonged use. Additionally, existing NV devices only provide a narrow field of view (FOV) and are limited to the near-infrared (IR) spectral bands, greatly limiting situational awareness in varied night conditions. ENVision seeks to leverage recent advances in planar optics and transduction materials to develop NV systems that don’t require bulky image intensifiers, provide wider FOV, offer enhanced visual access across IR bands, and are lightweight to reduce neck strain.

Five teams were chosen to develop multi-band, wide FOV planar optics and planar image intensifiers that impose near-zero neck torque on the wearer. Another five teams were selected to explore new methods to amplify photonic up-conversion processes from any IR band to visible light to enable future “intensifier-free” night vision systems.

For listing of the teams selected visit: https://www.darpa.mil/news-events/2022-01-12a