Abstract: The present invention is directed to a drug delivery pump apparatus, which comprises: (a) an expandable and contractible enclosure having an interior volume that defines a medication reservoir; (b) one or more electroactive polymer actuators; (c) a medication outlet port providing fluid communication between the interior volume of the contractible and expandable enclosure and an exterior of the delivery pump apparatus; and (d) a control unit electrically coupled to the one or more actuators and sending control signals to the same. The one or more electroactive polymer actuators act to reduce the interior volume of the contractible and expandable enclosure based upon the received control signals. The present invention is also directed to a method of delivering a liquid therapeutic agent to a patient.