Minimum weight design of a high authority flexural actuator based on electro-elastomers

A flexural actuator based on the operating principles of electro-elastomers has been proposed. The actuating element comprises multilayers of the electro-elastomer and a helical spring. The variables are the geometrical dimensions and the failure modes. A design that integrates this basic unit into a high authority flexural system has been analyzed. An optimization procedure has been devised and used to determine preferred designs. The analysis establishes the authority (product of end displacement and load to be lifted), at a specified electric field by determining the minimum weight as a function of the actuation strain and the number of electro-elastomer layers, n film . The dimensions of the constituents at the minimum weight emerge from the analysis. A comparison with a flexural actuator made using a one-way shape memory alloy reveals the performance advantages of the electro-elastomer system. An assessment of the variation in minimum weight with n film has provided a basis for a future weight/cost trade-off analysis.