A Novel Piezoelectric Inchworm Actuator Driven by One Channel Direct Current Signal

A novel piezoelectric inchworm actuator driven by one channel dc signal is developed in this article to simplify excitation signal of the inchworm actuators, and the clamping force of the developed actuator is generated by a dc motor and two permanent magnets. The piezoelectric stack is excited by a sensing signal, which is generated by the separate photoelectric sensor to detect the position of the rotational permanent magnets. A mathematical model is established to predict the motion of the slider. The prototype of the proposed piezoelectric actuator is fabricated, and mechanical output performance is measured. At a voltage of 75 V and frequency of 3.2 Hz, the average output step is 0.241 μm under no-load conditions. The proposed inchworm actuator can be operated by just one channel dc signal and the output displacement is stable, which provides a new idea for the integration design of the piezoelectric actuators in the future.