Theoretical Design and Modeling of a Novel Piezo-driven Rhombic Flexure Mechanism with Double Beams

Design and modeling of a new diamond micro-displacement mechanism with double flexible beams was presented to overcome the issue that the output stiffness, natural frequency and displacement amplification ratio of the traditional diamond displacement amplification mechanism might not be improved at the same time. The static analysis model of displacement amplification ratio and input/output stiffness of the mechanism were derived based on Castigliano's second theorem. Analytical model of natural frequency was also deduced by further employing the Lagrange equation. The finite element analysis was used to verify the accuracy of the analytical models. A prototype of the proposed compliant mechanism was machined by means of electric spark cutting processes and the performance measurement was performed for comparative analysis with the traditional mechanism with the same dimensions. Experimental results show that the natural frequency of the composite compliant mechanism is as 1330 Hz and displacement amplification ratio is as 4.2. In addition, the modeling method and the corresponding theoretical formula proposed herein may provide a useful reference for the optimal design and development of similar displacement amplification mechanisms.