Truth Behind the Elephant's Wrinkles
Muscular hydrostats such as octopi’s arms and the elephant trunk have received much attention because of their dexterity in grabbing a wide range of objects. These organs have inspired soft-robotic manipulators and actuators with various applications, from working with humans in confined spaces and disaster relief to picking up fruit. For soft robots to apply large forces, they will need protective skin. This work shows that wrinkles and folds in skin can provide protection and flexibility to soft appendages. We hope this work will inspire future work in the mechanics of skin in both animals and robots.
In 2020 we performed experiments at Zoo Atlanta with Kelly, a female mid-aged elephant, to see how her grip changes when lifting heavy barbells.
Movie 1. Elephant Lift! We had elephants lift barbells of different sizes to understand how their lifting changes.
We saw that the elephants were using their wrinkles differently as they were lifting and shifting the trunk in a way to optimize the number of wrinkles in contact with the barbell...to find out more we looked into the anatomy of the elephant.
Movie 2. A CT Scan of an elephant trunk shows us the complex inner muscle and wrinkles of the elephant trunk. Taken of a Frozen 38 year old elephant trunk.
Movie 3. Using the CT scan we can render a 3D object to understand how the wrinkles change along the elephant trunk.
Figure 3. If we look to the muscle of the trunk there are several different muscles including oblique, radial, and longitudinal muscles that control the motion of the trunk.
To find out more, check out the paper - which is open access online