Characterization of bending EAP beam actuators

Electroactive polymers (EAP) are attractive actuation materials because of their large deformation, flexibility, and low density. The large deformation, especially in the bending mode, poses a challenge to the material and actuator characterization due to the geometric nonlinearity that is developed during the characterization. A CCD camera system was constructed to record the curved shapes of bending during the activation of EAP films and image-processing software was developed to digitize the bending curve s. A computer program was written to solve the inverse problem of cantilever EAP beams with a tip position limiter. Using the program and acquired curve images with and without a tip position limiter as well as the corresponding tip force, the performance of the beam under different applied voltages and tip force loads was determined. The experimental setup, and the principles of the computer program are described and discussed in this paper.