Self sensing of elastomer actuation by means of AC superimposed current

Dielectric elastomers actuators are widely used for the development of artificial muscle. The need of a feedback on the actuation degree of the elastomer when applying the voltage is an important concern. Thus an integrated strain sensing system in dielectric elastomer actuators would be a step forward to achieving propioception of artificial actuators. One strategy that has been used in the past is the sensing of the electrode resistance during voltage application and elastomer actuation. In our work, we have performed measurements of AC current in a concentric dielectric elastomer actuator while superimposing a low frequency AC voltage to the applied DC high voltage by means of a high voltage amplifier. Results show that this magnitude can be related to the strain degree simplifying the complexity of the sensing system. However, it is also shown that the behavior of the electrode is complex and not constant with time thus needing further development.