Understanding the science behind an elephant’s trunk

The giant animal is unique for its ability to use suction on land and underwater

By   |  Published: 11th Jun 2021  7:45 pm

Washington: New research by the Georgia Institute of Technology finds that elephants dilate their nostrils in order to create more space in their trunks, allowing them to store up to nine litres of water. They can also suck up three litres per second a speed 50 times faster than a human sneeze.

The findings could inspire different ways to building robots that manipulate air to move or hold things. The study sought to better understand the physics of how elephants use their trunks to move and manipulate air, water, food and other objects. They also sought to learn if the mechanics could inspire the creation of more efficient robots that use air motion to hold and move things.

While octopus use jets of water to move and archerfish shoot water above the surface to catch insects, the Georgia Tech researchers found that elephants are the only animals able to use suction on land and underwater.

The paper, ‘Suction feeding by elephants’, is published in the Journal of the Royal Society Interface. “An elephant eats about 400 pounds of food a day, but very little is known about how they use their trunks to pick up lightweight food and water for 18 hours, every day,” said Georgia Tech mechanical engineering PhD student Andrew Schulz, who led the study. “It turns out their trunks act like suitcases, capable of expanding when necessary.”

Schulz and the Georgia Tech team worked with veterinarians at Zoo Atlanta, studying elephants as they ate various foods. For large rutabaga cubes, for example, the animal grabbed and collected them. It sucked up smaller cubes and made a loud vacuuming sound, or the sound of a person slurping noodles, before transferring the vegetables to its mouth.

“An elephant uses its trunk like a Swiss Army Knife,” said David Hu, Schulz’s advisor and a professor in Georgia Tech’s George W. Woodruff School of Mechanical Engineering. “It can detect scents and grab things. Other times it blows objects away like a leaf blower or sniffs them in like a vacuum.”