A suture is a join line. The box fish has an external skeleton made of stiff scales. These scales have a zigzag edge, like a jigsaw piece which allows them to interlock to form the strong skeleton. These joins allow the scales to move when the fish is attacked by predators therefore preventing the skeleton from cracking.
In textiles joins are known as seams. Seams are expected to be strong, and the fabric is where the flexibility is. Perhaps the flexible joins of the box fish can inspire a different approach.
Biology can teach us how sutures can help rethink the way we design joins.
The boxfish (Lactoria cornuta) relies on its unique, cube shaped exoskeleton for protection against predators.
The exoskeleton is not solid, it is composed primarily of interlocking scutes (stiff hexagonal dermal plates with zigzag edges). The jagged design of the scute edge enables adjoining plates to lock together, like pieces of a jigsaw. These form flexible joins (sutures) between the scutes.
Although scientists have yet to determine the precise purpose of the exoskeleton’s suture structure, the most popular theory is that it enables it to adapt to changing pressures of the creature’s ocean habitat or during growth. The flexible joins also helps protects the exoskeleton from forming, long, catastrophic cracks during attack from predators.