Memory of a mechanical metamaterial

Many disordered systems – granular suspensions, spin-glasses, crumpled paper – present history dependent features.
However, their complex geometry makes observing, understanding and controlling such memory effects challenging.
We introduce a class of patterned thin sheets that, when forced, exhibit controlled crumpling via elastic snap-through instabilities.
Individual snap-through events act as `hysterons' that can be observed directly, and that lead to complex yet fully observable deformation pathways, We explore a variety of memory effects in these system, and connect memory to pathways.