The secret ingredient to more powerful robots? Seahorse tails

Mechanical engineers have taken inspiration from an unusual location in their quest to build stronger, more capable robots - the tail of the seahorse.

Seahorses are pretty weird - while most of the animal kingdom has cylindrical tails, seahorse tails have a square-prism shape. It means they suck at swimming, but makes it way easier for them to grab hold of seagrass and corals and protect their fragile innards.

Grabbing and protecting their innards are two things that robots need to do a lot, so the researchers 3D-printed a square robotic tail and a round one to compare the two. They found that while the square tail had more limited movement, it required less energy to return to its original shape after being deformed.

It also created more contact points with a surface being gripped, allowing it to hold on more tightly.

Grasping and armour

"Almost all animal tails have circular or oval cross-sections — but not the seahorse's. We wondered why," said Michael Porter, the lead investigator on the study. "We found that the squared-shaped tails are better when both grasping and armor are needed."

Next, Porter and his team are planning on either scaling up the technology for a robot arm that can be used in 'hostile environments', or scaling it down to build a catheter. "You can simplify nature and study it in the lab," added Marc Meyers, also a co-author. "Then you can build new bioinspired structures and devices."

Their research was detailed in a paper in Science.