Effect of electrical terminals made of copper to the ionic electroactive polymer actuators

摘要

In order to diminish the effect of terminals to the aqueous ionic electroactive polymer (IEAP) actuators, the electrical input terminals should be made of a noble metal - platinum or gold. In any case, they should not be made of copper. As a matter of fact, copper is electrochemically not stable enough, even at very low voltages. As soon as a voltage is applied between the terminals, the ions of copper formed in the process of oxydation migrate very fast into the IEAP. The bending of IEAP actuators is caused by the movement of cations in the applied electric field. In the region of electrical terminals the infiltrated cations of copper will participate in this process and give additional effect. With the help of a showy experiment we compare the bending of a water-swollen ionic polymer membrane using terminals made of copper and made of gold. The experiment demonstrates impressively, that the copper ions originated from the copper contacts cause bending close to the terminals, and alter the composition of the membrane between the terminals.