Researchers at Baylor University are working on adapting lithophanes—an ancient artistic medium—for modern efforts to make scientific images accessible and understandable via touch. Lithophanes, which are thin, detailed engravings made from translucent materials, are thought to have originated in China as early as the seventh century and rose in popularity in Europe in the 1800s. The new lithophanes from the Baylor researchers are the first known examples of their kind and are intended for use as tactile learning tools for blind and visually impaired individuals. The new lithophanes can enable sightless or low-vision individuals to visualize microscopic and nanoscopic structures—for instance, in the subjects of anatomy and chemistry—with a greater level of detail and retainability than previously possible—and even at the same "resolution" as that of sighted individuals. See also: Learning; Visual impairment

Although cats are the number one lethal threat to birds, collisions with building glass are not far behind. The number of birds killed each year by glass collisions worldwide is estimated to be in the billons. In the United States, the U.S. Fish & Wildlife Service estimates that between 400 million and one billion birds die each year from collisions with buildings. In contrast, an annual average of only 250,000 bird deaths result from collisions with land-based wind turbines. See also: Aves; Building; Glass; Wind power

In the journal Science (September 2018), researchers reported a method for making a coating that reflects sunlight and radiates heat. The coating can be used to cool buildings and reduce air-conditioning use, keeping surfaces painted with the material about 6 degrees Celsius cooler than the surrounding air temperature. The paint can be easily applied to most surfaces, including the exterior walls and roofs of existing buildings. The cooling effect is based on a phenomenon known as passive daytime radiative cooling, whereby a surface cools without any energy input by reflecting ultraviolet to near-infrared solar radiation (278- to 4600-nanometer wavelengths) and radiating long-wave radiation (8000- to 13,000-nanometer wavelengths) through the atmosphere to outer space. Cool roofs designed using metals (such as aluminum) or white-pigmented paints help keep building temperatures lower by reflecting sunlight but are less effective at emitting the heat they absorb because heat is reflected inside these materials. See also: Buildings; Emissivity; Heat transfer; Infrared radiation; Paint and coatings; Radiation; Reflection of electromagnetic radiation; Solar radiation

Sand is mined for many applications. Sand is used for fracking, water treatment (filtration), metal casting, and making glass, silicon chips, and ceramics. But the largest use by far is for fine aggregate in concrete. Concrete consists of cement, water, fine aggregate (sand), and coarse aggregate (gravel). Aggregate makes up about 60–70 percent of the concrete volume, with 40–50 percent of the aggregate consisting of sand. The nearly 20-year-long construction boom in Asia, beginning in China, India, and Singapore, shows more signs of spreading than abating, with major projects for high-speed train lines, airports, roadways, and commercial and residential buildings planned in Indonesia, Malaysia, the Philippines, Thailand, and Vietnam. As a result, the demand for sand is huge. See also: Asia; Cement; Ceramics; Concrete; Glass; Hydraulic fracturing (fracking); Metal casting; Sand; Water treatment

Roman marine concrete, having lasted for nearly 2000 years, is a highly durable material. In contrast, modern marine concrete, which is made using Portland cement, may start to degrade in as few as 50 years. Researchers have now discovered why. As reported in the journal American Mineralogist (July 2017), they described the composition of the concrete and the chemical reactions responsible for its longevity. See also: Cement; Concrete

Due to their attractive properties, including high energy density and long cycle lives, lithium-ion batteries have become widely adopted in portable electronics and electric vehicles and continue to make inroads as renewable energy storage cells. However, as a raw material, lithium poses long-term economic and environmental sustainability concerns. These concerns include lithium's relatively high cost, looming scarcity, and negative environmental impacts from mining. As a potential alternative to lithium-ion batteries, researchers have been pursuing sodium-ion batteries (SIBs). Compared to lithium, sodium is significantly more abundant in Earth's crust, would be less expensive to obtain, and overall poses fewer environmental concerns. That said, sodium has proven far less tractable as a battery material. To address many of the issues that have stalled SIB advancement, researchers at Pusan National University in South Korea have developed new SIB anode materials. These new materials are efficient, are easily prepared, show high sodium-ion storage capacity, and have excellent cycle stability compared to their predecessors. The research team accordingly hopes that their technology can be used for large-scale production of sodium ion-based energy storage systems in the future. See also: Energy storage; Lithium; Mining; Sodium

Microplastics—tiny plastic particles measuring less than five millimeters (about 0.2 inches) in diameter—are a growing environmental problem worldwide and are extremely challenging to remove. The plastic particles can absorb or carry undesirable chemicals as well as disease-causing organisms, though the full extent of the harm microplastics may cause is unknown. A team of Princeton University research engineers recently found an efficient and cost-effective method for removing microplastics and other impurities from water by using standard egg whites. By creating an aerogel—a porous solid formed from a gel—from proteins found in egg whites, the team successfully removed nearly all the salt and microplastic contaminants present in seawater samples. This technology, which has breakthrough potential, is more effective at microplastic removal than existing processes, such as using activated carbon, and the low cost of its constituent ingredients shows promise for upscaling. See also: Egg (fowl), Gel, Materials science and engineering, Plastic waste pollution; Microplastics Are Raining Down On Us [Video]

Textiles are materials made of natural or synthetic fibers. They typically are produced by spinning fibers into yarns and then weaving or knitting the yarns into fabrics. Electronic textiles, or e-textiles, are fabrics with electronic circuits, devices, and interconnections woven, knitted, sewn, or embroidered into them using conductive yarns. E-textiles do not have to be wearable; they can just as easily be incorporated into home or office furnishings, such as carpets and drapes, as well as other nonapparel applications. In any case, e-textiles are characteristically lightweight and must be flexible, stretchable, washable, and resistant to strain, bending, and pressure. See also: Electronics; Manufactured fiber; Natural fiber; Spinning (textiles); Stress and strain; Textile

Researchers from the Massachusetts Institute of Technology (MIT), in collaboration with industry partners Stratasys and Autodesk, have used 3D printing technology to create objects that can self-assemble into new structures when desired. The process is called 4D printing because its designs involve not just the three physical dimensions but also planned changes over time. The research was led by Skylar Tibbits, director of the Self-Assembly Lab at MIT. Stratasys provided the 3D printer and materials, and Autodesk provided the software for self-assembly and folding design.

Many new-model electric vehicles (EVs) now have a driving range greater than 320 kilometers (200 miles). Consequently, range anxiety—the fear of running out of battery power before completing a trip or reaching a charging station—is becoming less problematic. Battery charging, however, remains an issue, as it may take as long as eight hours to recharge an EV battery to its full capacity. Nevertheless, thanks to advances in battery technology, a number of new and existing battery suppliers are reporting EV battery packs in late stages of development that can accept a full charge in 10 to 15 minutes. See also: Battery; Electric vehicle; Electric vehicles and range anxiety