Featherweight. (Tech News).IMAGINE a fridge-size hunk of solid--a state of matter with mass and volume made up of tightly bound molecules--that weighs just one pound and can hold up the weight of a Honda Civic The Honda Civic is a compact car manufactured by Honda. It was introduced in July 1972 as a two-door coupe, followed by a three-door hatchback version that September. With the transverse engine placement of its 1169 cc engine and front-wheel drive, like the British Mini, the . NASA NASA: see National Aeronautics and Space Administration. NASA in full National Aeronautics and Space Administration Independent U.S. is perfecting the world's lightest known solid, a hazy blue foam called an aerogel aerogel, any of a group of extremely light and porous solid materials; the lightest is less than four times as dense as dry air. Aerogels are produced from certain gels (see colloid) by heating the gel under pressure, which causes the liquid in the gel to become , also a strong insulator (material that blocks out heat or cold). A one-inch-thick aerogel slab can shield a delicate flower from a 1,400[degrees]C (2,600[degrees]F) flame and ward off cold better than 15 thermal windowpanes stacked back to back. What gives aerogel its feather-weight resilience? Air (99.8 percent) and the chemical compound silicon dioxide silicon dioxide: see silica. (SiO2) A hard, glassy mineral found in such materials as rock, quartz, sand and opal. In MOS chip fabrication, it is used to create the insulation layer between the metal gates of the top layer and the silicon elements below. or sand (0.2 percent). At the microscopic level, aerogel resembles a fishnet: Wisps of silicon dioxide molecules enfold en·fold tr.v. en·fold·ed, en·fold·ing, en·folds 1. To cover with or as if with folds; envelop. 2. To hold within limits; enclose. 3. To embrace. nanopores, tiny air pockets just 50 to 2,500 times larger than atoms themselves. "In making aerogel we wrap up a huge amount of solid in a very small volume," says University of Wisconsin researcher Stephen Steiner. "A sugar-cube-size piece has so many sides and surfaces that if you could unfold it, it would cover a basketball court." Aerogels, first invented in the 1930s, are already used in spacecraft, but Steiner envisions aerogel refrigerators, windowpanes, ovens, surfboards, even clothing: "We'll see how far we can push it!"--K. M. |
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