Design and Experiment Evaluation of a Rotatable and Deployable Sleeve Mechanism Using a Two-DOF Piezoelectric Actuator

A rotatable and deployable sleeve mechanism using a longitudinal-bending composite piezoelectric actuator was designed, fabricated, and tested. A two-DOF piezoelectric actuator with single driving foot was designed to work as the driver of the deployable sleeve mechanism: it could push the inner sleeve with linear, rotary, or spiral stretching motions, which was controlled easily by applying different exciting signals. The stretching principles of the proposed deployable sleeve mechanism were illustrated in detail and verified by means of the finite element method. A prototype of the two-DOF piezoelectric actuator was fabricated and the deployable sleeve mechanism was assembled. The mechanical output characteristics of the inner sleeve were tested and discussed. The proposed deployable sleeve mechanism achieved the maximum linear and rotary stretching speeds of 530 mm/s and 240 °/s when the voltage amplitudes and exciting frequencies were $300\,\,V_{\mathrm {p-p}}$ and 22.35 kHz. The spiral stretching ability of the deployable sleeve mechanism was validated experimentally. The linear and rotary stretching displacement resolutions of the inner sleeve were tested to be about $2~\mu \text{m}$ and 0.0014°, respectively. The proposed deployable sleeve mechanism obtained quick transient response characteristics with a starting time of 28 ms and a stopping time of 20 ms.