Predicting stick-slip motion for a legged, piezoelectric driven microrobot

The motion of a stick-slip microrobot propelled by its piezoelectric unimorph legs is mathematically modeled. Using a continuously distributed mass model for the robot's body, the motion equation of the mechanism is extracted based on the assumption of linear Euler- Bernoulli beam theory and linear piezoelectric behavior. Moreover, the required condition for generating net motion is derived in terms of physical characteristics of the microrobot. We have shown that the higher the friction coefficient, then a lower average speed is obtained. In addition, results reveal that a microrobot with heavier legs can move in a rougher environment. Furthermore, regardless of the mass proportion between robot's main body and its legs, a certain level of speed can, always, be achieved. The proposed results will be well suited to design, construct, and control the microrobots moving with piezoelectric benders, as their feet.

Keywords:

microrobot , stick-slip motion , piezoelectric bender