How to design and create reprogrammable mechanical metamaterials? Professor Martin van Hecke, PhD student Bastiaan Florijn, and postdoc Corentin Coulais recently published their findings on this in PRL. Metamaterials derive their unusual functionalities from their structure, not their composition. So far, such materials focus on a single feature: they may be strongly damping, or ultralight, or expand when compressed (negative compressibility). In their article, Van Hecke and his team introduce a class of mechanical metamaterials whose functionality can be controlled by confinement.

It consists of elastic (rubber) slabs with a carefully designed pattern of unequal holes. By controlling the clamping of this material, it can be normally elastic, negatively compressible, mechanically switching or extremely damping. Such materials may find applications from soft robots (see the Youtube video from the Whitesides Lab at Harvard) to wearable tech. Van Hecke explains: "Our work opens up the possibility for rationally designing a wide range of programmable matter." For further reading, click here.