Fabrics That Push Back; August 2012; Scientific American Magazine; by Davide Castelvecchi; 1 Page(s)

Call it the reverse psychology of stuff. Imagine a cushion that swells up instead of compressing when you sit on it. Or a rubber band that shrinks instead of elongating when you stretch it. If two physicists at Northwestern University are right, scientists may soon be able to make materials with such mind-boggling behavior.

The two researchers, Adilson Motter and Zachary Nicolaou, describe their proposal in work that appeared online in May in Nature Materials. (Scientific American is part of Nature Publishing Group.) They show how the unusual response, called negative compressibility, could theoretically emerge from putting together the right building blocks into a "metamaterial"—a material whose behavior is dictated not by its chemical or molecular composition but by its patterning at larger scales.