Collapsible dog bowls, bendable medical tubes and drinking straws all seem to work on a common principle, snapping into a variety of mechanically stable and useful states. Despite the many applications for such “designer matter” structures, however, the fundamental mechanisms of how they work have until now remained mysterious, say materials scientists at the University of Massachusetts Amherst led by Ryan Hayward.
Now he and colleagues including first author and Hayward’s former doctoral student Nakul Bende and their UMass Amherst colleague theoretical physicist Christian Santangelo, with mechanician James Hanna and students at Virginia Tech, report that they have figured out how these “multi-stable” structures composed of stacked conical sections are loaded with pre-stress, pent-up tension that arises “because the material is forced into a closed ring that is more tightly curved than it naturally wants to be,” as Hayward explains.
Details appear in the current online issue of Soft Matter.