A new robot skating on water surface intimating water striders based on flexible driving mechanism

The amazing ability of water striders on water surface has attracted many scholars. Especially the flexible driving mechanism enable the driving legs conform to the deformation of the water surface, which effectively improving water striders' floating ability and stability. However, the current research on water striders has never designed a flexible driven robot prototype like water striders. This paper proposes a new water strider robot that can walk on water surface based on flexible driving mechanism. The robot's driving legs are designed with flexible materials and possess ellipse-like spatial trajectories like water striders through a limit pin-linkage mechanism. Based on microelement cantilever method, the flexible driving effect was analyzed with different elastic modulus and diameter. It shows that the flexible legs can row at a higher frequency before puncturing the water surface and achieve bigger work in one period compared with the rigid one. At last, the skating experiment of the robot under different stiffness and rowing frequency was carried out. The results verified that the limit frequency of the flexible driving legs and maximum moving speed of the robot are about 41.3% and 36.2% higher than those with rigid legs, respectively. Moreover, a similarity analysis of hydrodynamic characteristic constants reveals that the locomotion of the flexible driving robot is more analogous to the biological water striders than the rigid one.