High field Maxwell stress-strain characteristics of conventional polymers as actuators

Polymers such as silicone and acrylic elastomers can strain via Maxwell stress. Experiments were carried out to elucidate how the two kinds of polymers would respond to a high electric field. Several kinds of electrode materials were tested to find suitable compliant performances, i.e., Al foils, Cu sheets, conducting stick tapes, conducting rubbers, Ag conducting paste, carbon black (Ketjen black), and sputtered Pt. Carbon black was preferred among them. Stress-strain characteristics are divided into a low field region and a high field region. Strain of several % is obtained for the elastomers subjected to 5 kV/mm. The first one seems to follow a quadratic dependence of strain on electric field, while strain tends to saturate in the second region. There are differences between theoretical and experimental values of strain, which should be further explored.