Design of a New Compliant Mechanical Amplifier

In this paper, a new topology that is a symmetric five bar profile for displacement amplification is proposed, and a compliant mechanical amplifier (CMA) based on the new topology is designed to amplify the stroke of a piezoelectric actuator. The new CMA can convert the motion generated by a PZT actuator with a large amplification ratio (24.4) in a very compact size, and it has a high natural frequency (573 Hz) and no lateral displacement. First, three existing topologies of CMA are analyzed and evaluated, which results in the new topology of CMA. After that, the new CMA is designed with different flexure hinges. The finite element analysis for the CMA shows that the double-beam symmetric five bar structure using the corner-filleted hinges can provide the best performance in terms of the displacement amplification and natural frequencies. The designed CMA is clearly better than the CMA based on the topology of a double symmetric four bar profile. Finally, the design is fine-tuned by examining critical parameters for the proposed CMA in light of a large displacement amplification ratio.