The mechanics of abalone crawling on sharp objects without injury.

Despite the soft appearance of their feet, abalones can crawl quickly on sharp objects. Tests using rough substrates aligned with blades or posts found that the animal has two adaptations to guarantee its safety on these surfaces. Mechanical compression tests showed that the abalone foot muscle is inherently robust and can resist penetration by sharp objects. A finite element simulation indicated that to avoid being pierced, abalone controls the shape of its foot to wrap it around sharp objects, thereby greatly reducing the stress concentration. These analyses may aid the engineering of new materials and devices for fields including soft robotics and aircraft.