More than 10-fold increase in the actuation strain of silicone dielectric elastomer actuators by applying prestrain
Silicone based dielectric elastomer actuators are preferred for reliable and fast actuation due to their negligible viscoelastic behavior. However, it is more challenging to achieve large deformation actuation using this class of polymers compared to the traditionally used VHB films. In this paper, we present theoretical guidelines for improving actuation strain of silicone based dielectric elastomer actuators. The electromechanical behavior of two different silicones is compared and it is demonstrated that the softest elastomer is not necessarily the best choice to achieve large deformation. Lastly, we have experimentally shown that uniaxially prestretching the elastomer with an optimum prestretch ratio enhances the actuation strain up to 10 times. Actuation strain of up to 80% on 100 × 100 μm2 microactuators is generated.