Looking for the simplest 3-D structure that could use mechanical instability to collapse reversibly, CEE Professor Pedro Reis, alumnus Jongmin Shim and co-authors created the buckliball, a hollow, spherical object made of soft rubber containing no moving parts, but fashioned with 24 carefully spaced dimples. When the buckliball is compressed, the thin ligaments forming columns between lateral dimples collapse — the engineering equivalent of applying equal load on all beams simultaneously to induce buckling. Read a news story.