The world\'s lightest solid material may bring refrigerators with thinner walls, better building insulation and other products, U.S. researchers say. Mary Ann B. Meador of the NASA Glenn Research Center in Cleveland reported on the development of a new flexible \"aerogel\" -- a material so light it has been dubbed \"solid smoke\" -- at the annual meeting of the American Chemical Society in Philadelphia Sunday. Traditional aerogels made from silica, found in beach sand, are brittle and break and crumble easily, she said. \"The new aerogels are up to 500 times stronger than their silica counterparts,\" Meador said. \"A thick piece actually can support the weight of a car. And they can be produced in a thin form, a film so flexible that a wide variety of commercial and industrial uses are possible.\" A quarter-inch-thick sheet provides as much insulation as 3 inches of fiberglass, she said, which could lead to refrigerators and freezers with thinner walls and greatly increased food storage capacity. It could also bring super-insulating clothing to keep people warm in the cold with less bulk than traditional \"thermal\" garments. Meador and her colleagues produced the stronger new aerogels by making changes in the innermost architecture of traditional silica aerogels and by incorporating a plastic-like material to reinforce the networks of silica in the aerogel\'s structure.