Piezo-driven precision positioning platforms with large stroke are greatly demanded in both scientific research and industrial applications. Although various principles have been proposed to design piezo-driven positioning platforms, the problem of backward motion commonly exists, greatly hindering their applications. To suppress the backward motion, in this paper, an idea by generating a forward frictional force to balance the reversed frictional force was proposed. Correspondingly, a specific arc-shape flexure hinge was designed to generate the forward frictional force via its elastic recovery. To verify the feasibility of the proposed idea, a positioning platform with alterable initial gap between contact surfaces was designed by the parasitic motion principle (PMP). By measuring the output displacement under various initial gaps, a critical initial gap was identified, at which the positioning platform could output stepping displacement without backward motion. Under this critical initial gap, effects of driving voltage and frequency on the backward motion were further investigated. In addition, the natural frequency and loading capacity of the positioning platform were tested. This study confirms that using PMP, it is feasible to design piezo-driven positioning platforms with completely suppressed backward motion, which would enhance the applications of the PMP and PMP positioning platforms.

Aiming to simulate the experimentally observed three kinds of one-stepping characteristics in stick-slip piezoelectric actuators, i.e., backward motion, smooth motion and sudden jump, a new dynamic model was proposed with consideration of the deformation of overall system. Being different from the existing dynamic models that consider the overall system as a rigid body, the stiffness coefficient and damping coefficient of the overall system were introduced in the newly proposed model. By adjusting the parameters according to the experimental conditions, these three kinds of characteristics were successfully simulated for the first time in this field. By comparison with the existing dynamic models of stick-slip piezoelectric actuators, the effectiveness, advancement, and necessity of the proposed dynamic model were demonstrated. This model is expected to be helpful for the structure design and performance prediction of stick-slip piezoelectric actuators.