Researchers have developed a groundbreaking morphing structure inspired by the starfish, boasting remarkable flexibility and stability. This innovative design, exhibiting 4D features, holds promise for applications in robotics, aviation, and medical devices.
Raman, a PhD student in the Biological Structures and Biomimetics workgroup at Hochschule Bremen, Germany, explained to Interesting Engineering that starfish can effortlessly maintain any body posture due to their intricate skeleton, which is a network of diverse tissues. Using advanced imaging techniques like X-ray CT scans, along with computational modeling and detailed image analysis, Raman and his colleagues deciphered the roles of these tissues and their interactions.
“Our goal was to unlock the secrets of their intricate skeleton and translate those principles into a novel material with similar remarkable properties,” Raman stated. Their work revealed the complex 3D structure of the starfish skeleton and the fine ultrastructure of the small ossicles for the first time. Ossicles, being calcite microstructures connected by collagen fibers, form a strong but simple endoskeleton that enables starfish to hold various body postures with minimal energy.
To emulate this biological design, the researchers 3D printed a thermoplastic mesh mimicking ossicles and collagen tissue, and enclosed it in a silicon rubber jacket. This unique combination endowed the structure with self-locking, continuous bending, self-healing, and shape memory features.
Unlike traditional morphing structures with stiff parts and joints, this starfish-inspired structure bends smoothly and continuously, even into complex curves. Additionally, it can self-heal: when damaged, the material flows and fuses upon heating above the thermoplastic’s melting point, effectively repairing itself. This capability was demonstrated with a hand-shaped prototype capable of complex unfolding motions without external motors.
This research signifies a major step toward energy-efficient morphing. Potential applications are vast, including adaptive automobile seats, advanced surgical tools, and re-shapeable prosthetics. The structure’s self-healing properties could revolutionize spacecraft structures and emergency shelters. Furthermore, it could lead to the next generation of robots capable of navigating tight spaces or handling delicate objects.
The researchers envision a future where adaptable, self-healing, and shape-changing objects enhance daily life. Imagine household items reconfiguring for different activities or toys transforming for endless play possibilities. The study, under review with Nature Scientific Reports, will be presented at the Society for Experimental Biology Annual Conference in Prague.
