Locomotion modes of a novel piezo-driven microrobot: Analytical modeling and performance evaluation

This paper presents a novel, sliding, A-shaped microrobot with nanometric resolution for precision positioning applications. The microrobot is actuated near its natural frequency using a piezoelectric stack actuator to produce translational motion. The dynamic modeling of the mechanism is based on the assumptions of the linear piezoelectric behavior and the Coulomb friction model. Using this model the required condition for generating net motion is found. The suitability of three simple, friction-based locomotion modes for implementation on the proposed device is addressed. Influences of some important configuration parameters on the behavior of the microrobot, based on defined criteria, are investigated. Even with non-optimal configurations, simulations show a velocity of 1 mm/s, a motion resolution of 180 nm, and a power consumption of 1.5 mW. Comparisons made with other microrobots of the same locomotion modes indicate good improvements in all criteria.