Starfish Inspired Milli Soft Robot with Omnidirectional Adaptive Locomotion Ability

Bionic robot inspired by creatures in nature attracts attention from researchers due to its effective locomotion mode and high environment adaptability. Despite the recent achievements in bionic research and robotics, the bionic robots are almost simple morphology imitation. While the imitation of functional texture and microstructures are also important, which always makes a significant difference to the performance of robot. In this work, we proposed a starfish inspired milli soft robot with excellent locomotive performance and great environmental adaptability. Different from the simple imitation of locomotion mode in the previous literature, we introduce the micro tube feet structures of starfish into the robot design. The magnetization measurement and friction test result indicate that the microstructures of tube feet can strengthen the driving performance of robot, reduce the motion resistance from ground, and enhance the obstacle-climbing ability. Benefit from the radial symmetry shape of the starfish, the milli soft robot can achieve omnidirectional movement under the actuation of magnetic field. Moreover, the large deflection modeling of the variable cross section antenna is built by analyzing the infinitesimal element, and two motion states of milli soft robot are compared. The successful locomotion demonstrations, including moving with “S” trajectory, adapting to wet surface and gravel surface, overcoming obstacles, indicate the potential application of the starfish inspired milli soft robot in harsh environment.