A material that expands under stress
AUG 05, 2010
DOI: 10.1063/PT.5.024560
Science : A new mathematical model has been developed to explain the bizarre behavior of auxetics—materials that grow thicker when stretched and thinner when released. Discovered nearly a century ago, auxetics have perplexed scientists and only recently has a team of researchers at the University of Malta been able to come up with an explanation, which they published in the Proceedings of the Royal Society A . Their model is based on one particular type of auxetic, represented by rectangles and squares, which rotate relative to one another such that as the thickness increases the density decreases (see animation ). Their research could lead to such diverse applications as bandages that dispense medication when a wound swells, better car bumpers, and earthquake-resistant buildings.
© 2010 American Institute of Physics
