Metamaterials that can count

Most metamaterials considered so far respond the same way every time they are driven.
Here we show how to construct a metamaterial that under cyclic loading iterates its internal configuration, reminiscent of the action of a cellular automaton. This metamaterial uses bistable, buckled-beam-elements to store information, and designs the beam shapes such that they deterministically flip neighbours at designed characteristic strains.
In particular we present a metamaterial that displays counting behaviour in response to compressive cycles. This work lays a new foundation for information processing in metamaterials.