High-stress dielectric elastomer actuators with oil encapsulation

Dielectric elastomer actuators (DEAs) can generate a large strain, but they are often short of strength and stress change for robotic applications. Their maximum actuation is limited by pre-mature electrical breakdown. This paper showed that dielectric oil encapsulation helps stop pre-mature breakdowns. Consequently, the oil encapsulated DEAs can sustain an ultra-high electrical breakdown field up to 835MV/m, which is 46% higher than 570MV/m in air without oil encapsulation. These oil-encapsulated DEA can produce muscle-like high stress change up to 1.05MPa, which is 75% higher than that produced by the DEA in air. Furthermore, oil encapsulation is also found effective to suppress electrical breakdown of tubular DEAs. These high-stress dielectric elastomer actuators show good potential to drive human-inspired robots.