To drive the electroactive polymer (EAP) materials and subsequently control their strain generation, the need for power electronics and driving circuits has been eminent. In this letter the authors demonstrate a spontaneous actuation of an electroactive polymer that requires only dc power to produce its ac responses. Such a dc-to-ac response of the EAP was achieved by the deposition of an effective electrocatalyst, i.e., platinum, on an ionomer, Nafion (TM). The coated ionomer was immersed into an acidic formaldehyde solution. An applied dc voltage will produce current oscillations in the system, and therefore oscillating bending of the actuator.