Semi-rigid ring-shaped electrode dielectric electroactive polymer membrane as buckling actuator

We propose a semi-rigid ring-shaped electrode layout for an out-of-plane buckling actuator using a dielectric electroactive polymer (DEAP) membrane. The electrodes are patterned around the deflectable membrane as a ring, rather than the usual compliant electrodes covering the whole membrane. One electrode is defined on the rigid substrate and the counter electrode on the flexible polymer. The buckling actuation is a result of the shear forces provided by the DEAP membrane between the ring-shaped electrodes. Comparing the results for different membrane thicknesses, shapes and electrode widths, we find that membranes accumulate compression strain without obvious deflection at low electric fields and then start deflecting linearly with electric field above a threshold of about 70 V mu m(-1). Furthermore, only a small effective region of the electrode area, approximately four times the membrane thickness contributes to the deflection. In the paper, we derive an analytical expression for the deflection and compare the simulation to experimental data.