Control waveforms applied to piezo elements used in a miniature robot

We developed a miniature robot using piezoelectric elements (PZTs). The miniature robot utilized the expansion and contraction of the PZTs. We applied rectangle waveforms to the PZTs and realized the rotational displacement of the robot. The rotational displacement varied widely when we used the rectangle waveforms. Optimal control waveforms, which were applied to the PZTs, were not clear. In this paper, we describe the rotation of the miniature robot, which is driven by three types of control waveforms; triangle, rectangle, and sinusoidal waveforms. The sinusoidal and triangle waveforms are suitable for the rotation of the miniature robot under our experimental conditions.