Enhancing Dynamic Bandwidth of Amplified Piezoelectric Actuators by a Hybrid Lever and Bridge-Type Compliant Mechanism

Ongoing interests in high-speed precision actuation continuously sparks great attention on developing fast amplified piezoelectric actuators (APAs) with compliant mechanisms. A new type of APA with enhanced resonance frequency is herein reported based on a hybrid compliant amplifying mechanism. A two-stage displacement flexure amplifier is proposed by synthesizing the lever-type and semi bridge-type compliant mechanisms in a compact configuration, promising to a well tradeoff between the displacement amplification ratio and dynamic bandwidth. The static and dynamic performances are experimentally evaluated. The resonance frequency of 2.1 kHz, displacement amplification ratio of 6, and step response time of around 0.4 ms are realized with a compact size of 50 mm × 44 mm × 7 mm. Another contribution of this paper is to develop a comprehensive two-port dynamic stiffness model to predict the static and dynamic behaviors of the compliant amplifier. The modeling approach presented here differs from previous studies in that it enables the traditional transfer matrix method to formulate both the kinetostatics and dynamics of compliant mechanisms including serial-parallel branches and rigid bodies.