Design and experimental evaluation of a compliant mechanism-based stepping-motion actuator with multi-mode

Stepping motion principle has been widely applied for piezoelectric actuators. A stepping-motion actuator driven by a compliant mechanism is proposed in this paper. Two degrees of freedom exist in the compliant mechanism, which offer the possibility for multiple actuation modes including stick-slip mode, semi-inchworm mode, and pseudo-ultrasonic mode. Actuation trajectories are planned according to the geometric model of the compliant mechanism and proven efficient. The dynamic characteristics of the compliant mechanism is concerned and its modal finite element analysis is performed. The performances of the actuation modes are verified in experiments. A brief verification of angular stick-slip mode, which improves the output force by 155.3% compared to stick-slip mode, is carried out. An actuation frequency up to 1.4 kHz is achieved by the prototype. The highest output force and the highest output speed of the prototype are 2.35 N and 3.75 mm s−1, respectively.