A bendable biological ceramic

Abstract

From a catastrophic bridge collapse to broken industrial equipment to the mundane snapping of a plastic latch, structures can break when their components fail because of fatigue—damage accumulation caused by repeated stresses. Fatigue is a problem not just for artificial structures but also for organisms. Running, jumping, chewing, flying: Many of life''s activities involve repeated loads that can cause fatigue failure (1), leading to injury or death. This places a high evolutionary pressure on avoiding and repairing fatigue-caused damage. Biomineralized tissues—such as bone, teeth, and mollusk shell—are often notably tough, fatigue-resistant structures that are built primarily from brittle ceramic components and thus have provided inspiration to materials scientists seeking to overcome the usual trade-off between strength and toughness (2–4). Unlike these relatively rigid structures, on page 1252 of this issue, Meng et al. (5) reveal multiscale, fatigue-resistance mechanisms of a robust, bendable biomineralized structure: the hinge of a freshwater mussel, Cristaria plicata.