A rolling locomotion method for untethered magnetic microrobots

It is a challenge to achieve free and efficient motion of microrobots on arbitrary surfaces. We report a rolling locomotion method for a magnetic microrobot with a rectangular body ( 300 × 200 × 50 μ m 3 ) ; this method is based on an external rotating magnetic field. The magnetic force, accompanied by normal and friction forces, enables the successive rotations of the microrobot. A magnetic field with a rotational speed of 2 rps rolls the microrobot, giving it a translation speed of 1.4 mm/s. With this locomotion ability, microrobots can move along a line or curve and can climb slopes or stairs.