This paper is concerned with beamlike space frames that include a large number of bistable elements, and exploit the bistability of the elements to obtain structures with multiple stable configurations. By increasing the number of bistable elements, structures with a large number of different configurations can be designed. A particular attraction of this approach is that it produces structures able to maintain their shape without any power being supplied. The first part of this paper focuses on the design and realization of a low-cost snap-through strut, whose two different lengths provide the required bistable feature. A parametric study of the length-change of the strut in relation to the peak force that needs to be applied by the driving actuators is carried out. Bistable struts based on this concept have been made by injection molding nylon. Next, beamlike structures based on different architectures are considered. It is shown that different structural architectures produce structures with workspaces of different size and resolution, when made from an identical number of bistable struts. One particular architecture, with 30 bistable struts and hence over 1 billion different configurations, has been demonstrated.

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This paper is concerned with the design of beam-like or surface-like structures for use, for example, as large spacecraft antennae, or as reconfigurable partitions in buildings that control air flow or sound. The idea is to construct structures that include a large number of bi-stable elements, and to exploit the two states of each actuator to set up different configurations of the structure. By increasing the number of actuators, structures with a large number of different configurations can be designed. A particular attraction of this approach is that it produces structures able to maintain their shape in a power-off state. The first part of this paper focuses on the design and realization of a low-cost snap-through strut, whose two different lengths provide the required bi-stable feature. A parametric study of the length-change of the strut in relation to the peak force that needs to be applied by the driving actuators is carried out. Bi-stable struts based on this concept have been made by injection moulding Nylon. Next, beam-like structures based on different architectures are considered. It is shown that different structural architectures produce structures with workspaces of different size and resolution when made from an identical number of bi-stable struts. One particular architecture, with 30 bi-stable struts and hence over 1 billion different configurations, has been demonstrated.

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This article presents a novel bistable structural element that has high stiffness in stable configurations, but requires only a small amount of energy to be switched from one configuration to the other. The element is based on a planar linkage of four bars connected by revolute joints, braced by tape-spring diagonals. A description of the concept is presented, along with a detailed theoretical analysis of its mechanical behaviour. Experimental measurements obtained from a prototype structure are found to be in very good agreement with the predictions from this analytical model.