Design and Implementation of Cone Dielectric Elastomer Actuator with Double-Slider Mechanism

Dielectric Elastomer Actuators (DEA) have a wide application prospect in the area of robot due to its merits. The aim of this paper is to improve the displacement of cone DEA and to make full use of the large-strain advantage of elastomer, as well as to reduce the volume and mass of actuator. After presenting the manufacturing process and working principle of cone DEA, it is analyzed that negative stiffness preload can enlarge the displacement of actuator significantly. Then a half-diamond mechanism is analyzed using double-slider model to implement a negative stiffness preload. Two points from force-displacement curves, foff and fon of elastomer with voltage on and off, are selected as two working equilibrium positions of actuator to calculate the parameters of the preload mechanism, hereby the negative stiffness mechanism is realized. Displacement experiments show that the cone DEA has a displacement of 20 mm under voltage 7541V and experimental results agree well with analytical results. Since the initial displacement is very small, so the large-strain advantage of elastomer is used for improving the displacement of actuator. In addition, the force outputs of the actuator when voltage is on and off are acquired, which shows actuator has a maximal force ability of 1.6 N.