Piezoceramic Telescopic Actuator Quasi-Static Experimental Characterization

Piezoceramic telescopic actuators capitalize upon an internally-leveraged amplification technique consisting of interconnected concentric, cascaded cylinders that telescope out when activated. The building-block nature of the telescopic design makes it an efficient, densely packed actuator that yields high work output for a given volume. As with any actuator, once fabricated, there are factors that lead to losses in performance that are not captured in most predictive models. To identify these and gain insight into the overall device behavior, this paper presents an experimental investigation of the quasi-static force-deflection performance. For a broader perspective, three unique telescopic prototypes were fabricated and experimentally tested, each manufactured using different techniques, materials, and geometries. As expected, discrepancies between the experimental and modeled behavior were observed. Therefore, to accurately predict the observed behavior of this architecture, a full three-dimensional numerical model was constructed for each prototype and was used to revise a previously derived analytical model accounting for the complex actuator behavior observed in the experiments and improving the characterization of the loss mechanisms in the telescopic actuation architecture.