Simple and high-performance stick-slip piezoelectric actuator based on an asymmetrical flexure hinge driving mechanism

This article presented a new type of stick-slip piezoelectric actuator based on an asymmetrical flexure hinge driving mechanism. The key of the driving mechanism was a four-bar mechanism with different minimum thicknesses of right-circle flexure hinges. Combined with a symmetrical indenter, the asymmetrical flexure hinge driving mechanism generated controllable tangential displacement by changing the locking force. Therefore, the simple structured stick-slip piezoelectric actuator achieved considerable improvements especially in output speed and efficiency. In order to obtain improved actuator properties, the minimum thicknesses of asymmetrical flexure hinge driving mechanism, the tangential and normal displacements of the indenter were analyzed and investigated by finite element method. A prototype was fabricated and experiment investigation of the actuator characteristics was presented. Testing results indicated that the actuator achieved the maximum velocity of 15.04 mm/s and its maximum load reached 440 g under a voltage of 100 V_p-p and a frequency of 490 Hz. The maximum efficiency of the actuator was 3.66% with a load of 280 g under a locking force of 5 N and the actuated velocity of 10.17 mm/s.