To try to figure out why, Schulz worked with colleagues at MPI-IS to 3D print a scaled-up whisker with a stiff, dark base and a soft, transparent tip. Having this physical “whisker wand” prototype helped the researchers develop their intuition for what an elephant trunk feels through its whiskers.
Schulz left the wand with his mentor after a meeting, and a few days later…Eureka! Kuchenbecker carried the wand in her hand as she walked through the halls of the Institute, gently hitting the columns and railings. She recounted, “I noticed that tapping the railing with different parts of the whisker wand felt distinct—soft and gentle at the tip, and sharp and strong at the base. I didn’t need to look to know where the contact was happening; I could just feel it.”
To test their hypothesis from the 3D-printed whisker wand, the researchers developed a computational modeling toolkit to assess how the unique geometry, porosity, and stiffness gradients they had measured affect how a whisker responds to contact. The simulations showed that the transition from a stiff base to a soft tip does indeed make it easier to feel where something is touching along the whisker, allowing the elephant to react appropriately and carefully manipulate even delicate objects, such as tortilla chips.
Schulz said, “It’s pretty amazing! The stiffness gradient provides a map to allow elephants to detect where contact occurs along each whisker. This property helps them know how close or how far their trunk is from an object…all baked into the geometry, porosity, and stiffness of the whisker. Engineers call this natural phenomenon embodied intelligence.” Excitingly, domestic cat whiskers show the same kind of stiffness gradient.
Elephant trunk whiskers exhibit material intelligence, revealing the secret behind an amazing sense of touch
We have hear how remarkable elephant trunks are our whole lives. Now there is eveidence to say why.