The Japanese spider crab is about to lose its title as the world's largest crustacean thanks to a new robot, the Crabster, developed in South Korea.
For the past 2 years, researchers at the Korean Institute of Ocean Science and Technology (KIOST) have been working on a giant robot crab that is about the size and weight of a Smart car.
This summer it will help scientists explore wrecks below the sea, weathering harsh tidal currents rushing over it at 1.5 m/s.
One of the key problems associated with traditional propeller-driven underwater remotely-operated vehicles (ROVs) and autonomous underwater vehicles (AUVs) is they don't perform well in strong currents. Another problem is their propellers tend to kick up a lot of detritus, lowering operator visibility.
To overcome these problems a team led by Principal Research Scientist Bong-huan Jun of KIOST designed a six-legged robot based on the characteristics of crabs and lobsters (hence the name).
The robot's six legs contain a total of 30 powerful joints. Like its biological cousins, the robot's two front legs are more articulated than the rest so they can be used as arms.
Objects can be picked up and stored inside a frontal compartment to be brought to the surface. Even in shallow seas it can get pretty dark down there, so the Crabster is equipped with 10 optical cameras and a long-range scanning sonar which scans up to 200 m (650 ft) away.