A piezo-driven compliant stage with double mechanical amplification mechanisms arranged in parallel

This paper proposes a novel piezo-driven compliant stage for long travel range with nano-motion. For long travel range, the piezo-driven compliant stage requires mechanical amplification mechanisms due to the short displacement of its stack-type piezoelectric element. The piezo-driven compliant stage consists of compliant mechanisms for both motion guidance and displacement amplification, stack-type piezoelectric elements, and high-precision displacement sensors. The mechanical amplification mechanism enlarges the output displacement of the mechanism, but it also reduces the output force of the mechanism. Since this reduction in force deteriorates the dynamics of a moving object driven by a mechanical amplification mechanism, an output force reinforcing mechanism is required. To overcome this problem in a piezo-driven compliant stage for long travel range and nano-motion, two mechanical amplification mechanisms arranged in parallel are introduced. Under this arrangement, one mechanical amplification mechanism pushes the moving object, while the other pulls it to provide twice as much force. The proposed compliant stage was analyzed, designed, and machined by wire electro-discharge machining. Finally, experiments were carried out to demonstrate the performance of the piezo-driven compliant stage.