A robot inspired by mantis shrimp has been created by a team of researchers at Zhejiang Sci-Tech University and the University of Essex.

According to its developers, the robot could be used in applications such as exploring and monitoring narrow and difficult-to-reach underwater environments inhabited by various species of animals and minerals.

Credit: Chen et al.

Inspired by the mantis shrimp’s flexibility and fast swimming speeds, the team set out to develop a fast-moving underwater robot that can access narrow underwater environments.

The agile robot features 10 artificial pleopods, which are the limbs attached to crustaceans, and a flexible body with strong propulsion capabilities.

"The bionic mantis shrimp robot is driven by five pairs of pleopods," the researchers explained. "A balance of velocity and stability can be achieved by adjusting the movement frequency, amplitude, and phase difference of the motion of these five pairs of pleopods. In addition, the connection of each pair of pleopods is independent, which is very useful for repairing in case of structural damage underwater."

In addition to the artificial pleopods, the researchers explained that the mantis shrimp robot is controlled via the bending of its flexible torso using a wire. The combination of the wire and pleopods enable the robot to quickly change direction. In the event one of the pleopods — which feature one active joint driven by servomotor and two passive joints — fail, the robot can rely on the other pleopods.

To achieve maximum propulsion, one of the robot's limbs moves backwards while the three joints fully expand. Conversely, when the robot’s limb returns to its original stance, the joints fold, thereby reducing forward resistance.

In the lab, the researchers tested a prototype and discovered that it moved well underwater and reached maximum velocity of 0.28 m/s as well as a minimum turning radius of 0.36 m. Further, the mantis shrimp robot can be precisely and easily controlled, thus limiting collision risks with underwater obstacles.

The mantis shrimp robot is detailed in the article “Design and Control of a Novel Bionic Mantis Shrimp Robot,” which appears in IEEE/ASME Transactions on Mechatronics.