Mechanics and Materials of the Elephant Trunk with Applications to Conservation Technology

An elephant trunk is both flexible and strong, able to pick up peanuts and uproot entire trees. This versatility has made the elephant a model for soft robotics studies that seek to build strong, flexible manipulators. By observing elephant behaviors during different mechanical tasks including elongation, wrapping, and suction feeding we can begin to understand the limitations and capabilities of this hydrostat. We further the understanding of these behaviors by looking into the mechanical properties of the elephant trunk’s skin including the wrinkled behavior commonly seen externally. Using novel human-based approaches we see the elephant skin’s collagen fibers are entangled leading to largely non-linear response behaviors that lead to macro asymmetries during elongation. We see that both morphology and composition of the trunk play distinct and complementary roles throughout the trunk. These roles allow flexibility and protection on the upper portion of the trunk and gripping rigidity on the underside. To further understand these skin morphologies we turned to programmable knitted mimics to vary geometry, morphology, and extensibility at different sections along the trunk. Together, these results may help inform future design of soft robotic skins that can exhibit durability, sensitivity, and strength. In parallel with this research, we understand that the elephant is a newly vulnerable species and therefore the idea of bio-inspiration of the trunk will go extinct with the species if we do not work to counter the sixth-mass extinction. We report work towards creating novel conservation tools using machine learning, computer vision, and frugal hardware that foster new collaborations to help counteract zoonotic transmission and bio-diversity loss. We end with a future perspective of bio-inspired tactile sensory in the Scarlet Ibis.