This paper presents a new concept of actuators and bellows based on the rigid foldable cylinder discovered recently. Connelly et al proved that when a concave polyhedron is deformed, its volume remains constant in 1997. In spite of this rigorous mathematical theory, we have observed a real model of rigid polyhedral cylinder which changed volume substantially at some particular situation. Inspired with this phenomenon, we have identified that particular situation where the model, made of practical engineering material, can change its volume. This phenomenon is now applied to propose the new concept for actuators and bellows.