The invention involves providing a reset signal before and or after one or more actuation signals to an electroactive polymer structure of an actuator. The reset signal can cause relaxation of defects such as e.g. trapped charge, dipoles and/or others in the EAP or EAP structure so that upon a subsequent activation using a drive signal, the initial actuation state is defined to be more constant than without use of the reset signal. Hence the actuation 5 output of a device employing the invention is more reproducible. The invention is applicable to actuator devices that have an electroactive polymer structure including an EAP material, where the structure is capable of providing a mechanical actuation upon subjection of at least part of the EAP material to an electrical drive signal.