The need for speed

Development of dielectric elastomer actuators has been mainly targeted towards achieving giant static strain with little attention paid to their response speed, which can, depending on materials used, be as long as tens of seconds. However, most of the practical applications require actuators capable of changing shape quickly, therefore a careful choice of materials and technologies for the dielectric and electrodes must be made. Test oscillating actuators, made with a range of silicone membranes with different hardness were tested, and the compliant electrodes were made with different technologies: carbon powder, carbon grease, conductive rubber and metal ion implantation. The transient response of the actuators to a step input was measured with a high speed camera at 5000 frames per seconds for the different combinations of membrane material and electrodes. The results show that the dynamic response of the actuators is extremely dependent on the membrane material, as expected, but also on the compliant electrodes, whose impact cannot be neglected.

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