Building blocks of the future defy logic: New logic-defying mathematical model

Wake up in the morning and stretch; your midsection narrows. Pull on a rubber band and it becomes thinner. One might assume that materials will always stretch and thin. Wrong. Thanks to their peculiar internal geometry, auxetic materials grow wider when stretched. After confounding scientists for decades, researchers are now developing mathematical models to explain the unusual behavior of these logic-defying materials, unlocking applications from better skin grafts to new smart materials.