How elephant’s flexible trunk can improve robots


A recent study has suggested that an elephant’s muscles aren’t the only way it stretches its trunk, but its folded skin also plays an important role. The research finding has shown that the elephant’s skin doesn’t uniformly stretch as the top of the trunk is more flexible than the bottom, ANI reported.

The findings could be helpful in improving robots which are built for either good strength and flexibility. The fluid-filled cavities of soft robots can allow flexibility, but it easily breaks away when forces are employed, the ANI report said.

An elephant’s trunk can produce both flexibility and strength. The creature can easily capture delicate vegetation and break apart tree trunks thanks to the adaptability of its muscle and skin combination.

The researchers say the elephant findings suggest that wrapping soft robotics with a skin-like structure could give the machines protection and strength while continuing to allow flexibility.

Andrew Schulz, the study’s lead author and a Ph.D. student in Georgia Tech’s George W. Woodruff School of Mechanical Engineering, and his team filmed two African savanna elephants reaching for bran cubes and apples at Zoo Atlanta.

They expected that elephant’s trunk like our ‘muscle-filled, boneless tongue’ will stretch uniformly to reach for food.

“But when we looked at our high-speed camera footage and plotted the trunk’s movements, we were surprised. The top and bottom weren’t the same at all,” Schulz said.

After seeing the video, Schulz stretched the tissue of a dissected elephant to better understand the skin’s elasticity. That’s when he found that the top of the skin, which is folded, is 15% more flexible than the wrinkled bottom side. It’s also when the team realized they weren’t just seeing muscle movement in the video. They were also tracking a thick sheet of skin.

As a mechanical engineer, Schulz sees the applications of robotics in it.

“Soft robotics created with biologically inspired design are always based on muscle movement. If they were wrapped with a protective skin, like an elephant’s muscle-filled trunk, the machines could apply larger forces,” he said. “Last year we learned that a trunk is a multi-purpose, muscular hydrostat. Now we know that skin is another tool at its disposal.”

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How unique is Elephant’s trunk

A report published in journal Current Biology terms the elephant trunk unique as it can manipulate a single blade of grass but also carry loads up to 270 kilograms.

The Georgia Tech study found that an elephant trunk is different from other boneless, muscle-filled appendages found in nature, such as squid and octopus tentacles. Instead of extending evenly, an elephant telescopically stretches its trunk like an umbrella, gradually lengthening in waves.