Development of water surface mobile robot inspired by water striders

Abstract

This work describes a water surface mobile robot utilising surface tension forces. Recent biological studies on water striders revealed how they stay afloat and move on the surface of water. By using their hairy legs coated with hydrophobic substance produced, they increase the water repellency and float by the surface tension. This work focuses on understanding the static and dynamic interactions between supporting legs and the surface of water. First, microstructured wire legs were fabricated by using femtosecond laser machining to enhance the water repellency. Then the supporting force, the pull‐off force and the drag force were measured to find the suitable legs for water strider robot. Finally, by assembling the legs optimised for supporting load and propulsion, a water strider robot weighing 4.39 g was developed. The robot successfully moved on the surface of water at a speed of 59.2 mm/s.