Sea creatures inspire sea robots that can operate in extra-terrestrial oceans

This robotic unit called RoboSalps, after the name of the animal, has been engineered to operate in unknown and extreme environments such as extra-terrestrial oceans.

Although salps resemble jellyfish with semi-transparent barrel-shaped bodies, they belong to the Tunicata family and have a complex life cycle, alternating between solitary and aggregate generations where they connect to form colonies.

RoboSalp have similar lightweight, tubular bodies and can connect with each other to form ‘colonies’ which give them new abilities that can only be achieved by working together.

Researcher Valentina Lo Gato belongs to Bristol Aerospace Engineering Department currently leading a study. He is also a student at the EPSRC Doctoral Training Center in Autonomous Systems and Future Robotics (FARSCOPE CDT).

He said: “RoboSalp is the first modular salp-inspired robot. Each module is made of an extremely light soft tubular structure and drone propellers which allow them to swim. These simple modules can be combined into much more powerful ‘colonies’ that have the potential to perform complex tasks. Due to their low weight and robustness, they are ideal for extra-terrestrial underwater exploration missions, for example, in the subsurface oceans on Jupiter’s moon Europa.”

RoboSalp is unique in that each individual module can swim independently. This is possible because a small motor with rotor blades – usually used for drones – is incorporated into a soft tubular structure.

When swimming alone, the RoboSalps modules are difficult to control, but after joining together to form a colony, they become more stable and exhibit sophisticated locomotion.

Additionally, by combining multiple units, scientists automatically obtain a redundant system, which makes it more robust against failure. If one module is damaged, the entire colony can still move.

Soft robot colonies are a relatively new concept with many interesting applications. RoboSalps is soft, potentially quite energy efficient, and robust due to its inherent redundancy. This makes them ideal for autonomous missions where direct and rapid human control may not be possible.

Dr. Helmut Hauser belongs to Bristol Mathematics Engineering Department, explained: “This includes exploration of remote submarine environments, sewage tunnels, and industrial cooling systems. Due to the low weight and softness of the RoboSalp modules, they are also ideal for extra-terrestrial missions. They can be easily stored in reduced volumes, ideal for reducing the payload of global space missions.”

Compliant bodies also provide for safer interactions with potentially fragile ecosystems, both on Earth and beyond, thereby reducing the risk of environmental damage. The possibility to detach units or segments, and rearrange them, lends adaptability to the system: once the target environment is reached, the colony can be deployed to begin exploration.

At some point, it may split into segments, each traveling in a different direction, and then reassembling in a new configuration to achieve a different goal such as manipulation or sample collection.

Prof. Jonathan Rossiter added: “We are also developing a control approach that can exploit the compliance of the module with the goal of achieving energy-efficient motions that approach those observed in biological salps.”

tags: inspired bio