Experimental Investigation of a Loaded Circular Dielectric Electro-Active Polymer Actuator Coupled to Negative-Rate Bias Spring Mechanism

A constant force input, a linear spring, and a bi-stable mechanism are separately tested as the biasing element of a circular/diaphragm DEAP. Each of the bias elements are systematically coupled to an unloaded 2 layer DEAP and are tested under various DEAP pre-deflections, bias element stiffness and electrical loading rates. The out-of-plane displacement output is measured as the voltage is cycled. The tests showed that the bi-stable element, with aid of a mechanical stop, gave the largest displacement output. This bi-stable element actuator is then tested against a hanging mass to examine the work capabilities against a constant force. However, the actuator failed to work even against a hanging mass of 20 grams. This change in behavior of the actuator is analyzed by considering the force equilibrium curves. Finally, suggestions are made for the design of future biasing methods in order to achieve higher actuator performance.