Compliant Toggle-Linkage Mechanisms: A New Type of Displacement–Force Amplification Principle

Abstract

A compliant toggle-linkage mechanism with the dual functions of displacement amplification and reduction is proposed. A series of compliant amplification mechanisms are examined by combining multi-group flexure toggle linkages, showcasing a flexible design with modular flexure toggle-linkage building blocks. A compliant toggle-lever mechanism is then investigated in detail as a displacement amplifier and a reducer for piezoelectric actuators by exchanging the input and output ports. Its kinetostatic and dynamic performances are captured using an improved dynamic stiffness matrix modeling procedure with high prediction accuracy and robustness, which shifts the end nodes of all adjacent flexure hinge/beam members to be coincident in order to deal with the irregular connection of building blocks. It is interestingly observed that the output displacements with forward and reverse motion directions can be simultaneously achieved with such a compliant toggle-lever mechanism by changing the structural parameters. Finally, the relationship of displacement amplification and reduction ratios between the input and output ports is clarified and discussed by comparing the results among the dynamic stiffness matrix model, finite element simulation, and experimental testing.