Design and analysis of a displacement amplifier with high load capacity by combining bridge-type and Scott-Russell mechanisms

To improve the load capacity of flexure-based amplification mechanisms, a flexure-based displacement amplification mechanism is developed in this study by combining the bridge-type and the Scott-Russell mechanisms. The four arms of the traditional bridge mechanism are replaced by four Scott-Russell mechanisms that provide the advantages of good symmetry, compact structure, and higher load capacity. An analytical model is formulated using a stiffness matrix to analyze the natural frequency, input and output stiffnesses, displacement amplification ratio, and load capacity of the proposed mechanism. The design model was subjected to both experimental methods and finite element analysis for verification, and the two sets of results were in good agreement. This proves the effectiveness and applicability of the analytical model and the proposed amplification mechanism. The output stiffnesses of the modified bridge-type amplifier and the traditional bridge-type amplifier are 0.158 N/μm and 0.041 N/μm, respectively, indicating excellent load performance of the modified bridge-type amplifier.