Abstract: The design of most water strider robots follows the principle that all supporting legs are in a plane, and each supporting leg bears a certain load and the water strider robot can float on the water. To meet this principle, the number of supporting legs and the spacing between each supporting legs of the water strider robot must be increased, which makes the shape of water strider robots look like octopus. This study proposed a novel water strider robot named 5S-robot, which used five new umbrella-type footpads and a centrifugal pump-based actuating mechanism. Motion analysis model and force analysis model of 5S-robot were built. The general consistency between the results of motion experiments and those of numerical simulation verified the former models. For this 5S-robot, the maximum load of 110.5 g and forward speed of 207.1 mm s?1 and rotational speed of 1.22 rad s?1 were measured, respectively.

Key words: Umbrella-type footpad, Water strider, Non-parallel arrangement, Pump-based actuating mechanism