Robot locomotion by fluid-fluid interaction.

This paper describes a locomotion strategy for robots based on the interaction between two fluids, through the development of an untethered mobile robot. The fundamental principle of robot locomotion is to exploit the active deformations of ferrofluid caused by internal magnetic fields, which generate reaction forces to the surrounding fluid (in this study, water). The developed robot is equipped with two permanent magnets (PMs), two electromagnets (EMs), two clusters of ferrofluid, and a control unit with batteries.