Elastic instabilities in mechanical metamaterials can be harnessed to programme fracture behaviour, transforming instability from a failure mechanism into a design principle that increases fracture energy by up to tenfold.

How this affects you

This work represents a shift from passive observation to active control of fracture mechanics, establishing a new framework for designing metamaterials with tailored fracture resistance. It advances the fundamental understanding of instability-fracture interactions in metamaterials and suggests a broadly applicable route for programming fracture behaviours through instability design.