This example allowed the MIT team to create the simplest three-dimensional structure that could take advantage of mechanical instability to reversibly collapse. Using 3D printing techniques, they made a hollow sphere out of a rubber-like material. It had no moving parts. Instead, it was fashioned with 24 carefully spaced dimples. They called this a “buckliball” because of its resemblance to the buckyball carbon nanostructures, plus it’s a play on the phrase “bucklely ball." This is why scientists don’t write advertising copy.These buckliballs hold their shape quite nicely when inflated, but take the air out and they fold in on themselves quite dramatically. The thin ligaments between the dimples collapse and all the bits (or the structure) start to move in a remarkably orderly fashion. They just sort of slide past one another in a rubbery dance. Some bits go clockwise, others go anticlockwise and it all folds into a nice little “rhombicuboctahedron" – that’s an irregular geometric solid with eight triangular and 18 square faces, if your Euclid is a bit rusty. It’s also the first morphable structure to incorporate buckling as a engineering element. That’s pretty impressive for a bit of plastic without any moving parts.