Sombot: A Bio-Inspired Dynamic Somersaulting Soft Robot

Natural animals always provide inspirations for soft robot designs, and the evolved locomotion mechanisms perfectly adapted to specific environments motivate a lot of robots to pursue superior mobility. The small stomatopod named Nannosquilla decemspinosa possesses a unique form of locomotion-backward somersaulting which allows the animal to move flexibly and rapidly on soft and moist sand. In this letter, we present a bio-inspired dynamic somersaulting soft robot (SomBot) with ultra-fast moving speed (maximum speed is over 0.94 m/s). To mimic the unique somersaulting of the stomatopod, a simple prototype containing a pneu-net actuator body and a suction is developed. With the help of the controllable anchoring exerted by the suction, the curling deformation of the body actuator can be converted into the fast somersaulting movements. The dynamic somersaulting mechanism is modelled and analyzed. Deformation tests are conducted for the body actuator to provide guidance for the somersaulting control. The fully soft SomBot prototype exhibits a much faster speed (9.2 body lengths per second) than the reported fast-moving soft robots, which demonstrates the dynamic somersaulting mechanism has great potential for designing soft locomotion robots with superior mobility.