A team of engineers at the University of Iowa has developed a new underwater technology that takes inspiration from the incredible abilities of the octopus.
Their invention could make future underwater vehicles more agile, energy-efficient, and capable of navigating even the trickiest environments.
The work comes from the lab of Caterina Lamuta, an associate professor of mechanical engineering who has been exploring ways to mimic the muscles, skin, and tissue of octopuses.
These sea creatures are masters of movement and adaptability, able to change shape, slip into tiny spaces, and control how water flows around their bodies.
Lamuta and her team wanted to bring some of that flexibility into the design of underwater machines.
In their latest study, the researchers created what they call twisted spiral artificial muscles. These synthetic coils mimic the special papillae muscles found in an octopus’s skin.
In nature, papillae can uncoil instantly to help with camouflage or to adjust how the animal moves in different water conditions.
The team applied the same idea to underwater vehicles by adding the coils to the wings of a hydrofoil, a common structure used in marine craft to generate lift underwater.
The modified hydrofoil had two rows of four artificial muscles, each powered by small electrical motors called actuators.
When the motors activated, the coils unspooled like tiny springs, changing the flow of water around the wings. This reduced drag—the resistance that slows a vehicle down—and increased lift, which helps it move more smoothly and efficiently.
In experiments with water flowing at different speeds, the hydrofoil performed significantly better. The team reported up to a 30% increase in lift and a 10% reduction in drag during certain maneuvers.
That means the hydrofoil could displace water more easily and maintain control even when tilted steeply against the current, a situation that normally makes maneuvering difficult.
“This study can help make unmanned underwater vehicles more efficient, using low-cost artificial muscles that are bioinspired by the motion of octopus papillae muscles,” said Rabiu Mamman, the study’s first author and a doctoral student in mechanical engineering.
“It can help save energy and improve the portability and maneuverability of seafaring vehicles.”
The researchers note that this is the first time an underwater flow-control device has been powered by twisted artificial muscles.
The breakthrough could have a wide range of uses, from inspecting pipelines and underwater infrastructure to collecting delicate specimens from deep-sea environments where maneuverability is key.
The study, published in Robotics Reports, marks an early but promising step toward creating a new generation of underwater vehicles.
By drawing inspiration from one of the ocean’s most adaptable animals, the team has shown that machines can become more efficient and versatile when they borrow from the designs perfected by nature.
