Tristable bending mechanism

Embodiments of a tristable bending mechanism are described in which an elastic component is provided which serves both as a structural component in the kinematic chain of the mechanism as well as a power storage component of the mechanism. The elastic component holds a movable arm and an input connection to either a first stable state or a second stable state when the ends of the elastic component be held in position so that the elastic component has a state with high elastic deformation energy. In a third stable state in which the elastic members is in a relaxed state with less elastic deformation energy, the mechanism may be in a released state, which is different from the closed and open state.