Design of a robot with biologically-inspired swimming hairs for fast and efficient mobility in aquatic environment

A water beetle is skillful at drag-powered swimming by using its oar-like legs. Inspired by this mechanism, a miniature robot, whose mobility is obtained by a pair of legs attached with swimming appendages, was studied in this work. The robot in this paper has optimally designed linkage structures to maximize the sweep angle, which is actuated by a single DC motor with series of gears and a spring. A simplified swimming appendage model was proposed to calculate deflection by drag force applied. Also, each of swimming appendage was optimized individually by considering the attached locations on the legs using the two fitness functions, and three different configurations were selected. In the experiments, the performance of the proposed robots was verified using a high-speed camera, and motion capture cameras. The robot with the proposed configuration showed the fastest movement comparing with other robots.