Floating robotic insects to obtain electric energy from water surface for realizing some self-powered functions

Microrobots that are light and agile possess unique advantages over conventional robots. Key challenges in the design of microrobots include the external power sources and the complex propulsion strategies. Here, inspired by the water strider, we realize a multi-functional self-powered microrobot that can walk on the surface of water, light up a LED and power a temperature sensor, without an external power supply. The self-powering functionality was provided by superhydrophobic wires as the artificial legs of the microrobot, which can obtain electrical energy from water surface with an output voltage of 1.38 V and an output current of 25 mA. We developed a propulsive mechanism with the dynamic coupling of a motor and shape memory alloys to paddle the side superhydrophobic legs of the microrobot, leading to a forward locomotion with an average speed of 1.45 cm/s. Our work could provide open prospects to develop self-powered microrobots in aquatic environments.