Abstract: By imitating the body structure and movement mode of the crab in nature, a novel stick–slip piezo-driven positioning platform was proposed by employing the bionic flexible hinge mechanism with a symmetrical structure and two piezoelectric stacks. The structural design and bionic motion principle were discussed, followed by analyzing the feasibility, safety, and output magnification ratio of the bionic flexible hinge mechanism via the stiffness matrix method and finite element simulation. To investigate the output performances of the positioning platform, a prototype was fabricated and an experiment system was established. Stepping characteristics of the positioning platform under various driving voltages were characterized, and the results indicated that the positioning platform could move steadily under various driving voltages. Within 1 s, the differences between the forward and reverse output displacement were less than 3% under different driving frequencies, proving the high bidirectional motion symmetry. The maximum driving speed of 5.44 mm/s was obtained under the driving voltage of 120 V and driving frequency of 5 Hz. In addition, the carrying load capacity of the positioning platform was tested by standard weights, and the results showed that when the carrying load reached 10 N, the driving speed could still reach 60 μm/s.

Key words: Piezo-driven , · Stick–slip , · Bionic design , · Positioning platform , · Bidirectional motion symmetry