Motion analysis of a vibrational micro-robot with two perpendicular harmonic actuators and deriving the design parameters in stick-slip-jump mode

In this paper, the motion of a micro-robot with two perpendicular vibrational actuators is studied. In this work, separation of the micro-robot body from the substrate of motion takes place. The separation happens while the vertical force applied to the micro-robot body is greater than the micro-robot weight. In this condition, body of the micro-robot jumps apart from the substrate and then returns to it, and this motion will continue intermittently until it becomes damped. In this condition, the motion mechanism of “stick-slip” is not valid and we introduce a new mechanism of hybrid motion as “stick-slip-jump”. In this case (hybrid motion), the micro-robot dynamics is modeled and the result is simulated. Then, its design parameters are derived and the condition of motion capability is determined. At last, a practical model of this micro-robot is designed and fabricated with two piezo-electric actuators, and then the motion of the micro-robot is verified by test.