Design of a compact bistable mechanism based on dielectric elastomer actuators

Bistable mechanisms are widely used in the applications where two stable positions must be held for long time without energy consumption. The main advantage of bistable mechanisms is a sensible reduction in bulkiness and energy cost. Among the possible active triggering systems, dielectric elastomer actuators (DEAs) are gaining attention, for their efficiency and strain rate, as a viable alternative to traditional technologies. In the present work, a novel design of a bistable system is proposed, counting on a cross-like shape bistable element coupled with two axially arranged conical DEAs. Analytical and FEM models have been used to implement and analyze the behavior of the single components and the final coupled system. The obtained results confirm the feasibility of the switching process between the equilibrium points and the capability to capture and numerically describe the interactions between the actuators and the bistable beams. A specific device has been finally envisaged to exemplify the possibility to develop a light-weight and compact system able to sustain and passively maintain a linear displacement which equals the 46 % of its own total length.