Hybrid force and position control of a conducting tri-layer electro-active polymer actuator

In this study, the displacement and blocking force of the tip point of a cantilevered electro-active polymer (EAP) actuator has been controlled for a cell injection process which consists of approaching, interacting and leaving steps. A vision-based system is used to acquire the tip displacement data for identifying a transfer function model of the actuator and its position control. Discrete time Proportional-Integral controllers are used to control the position and blocking force. A Smith Predictor is utilized in the vision-based position control system to compensate for the time delay due to image processing. Experimental position and blocking force results prove that the proposed control strategies are effective enough to guide the actuator to undertake the cell injection process. This study contributes to the previously published work from the point of view of simultaneously controlling the position and blocking force of the electroactive polymer actuators and widening their application areas.