This paper describes two folded metamaterials based on the Miura-ori fold pattern. The structural mechanics of these metamaterials are dominated by the kinematics of the folding, which only depends on the geometry and therefore is scale-independent. First, a folded shell structure is introduced, where the fold pattern provides a negative Poisson’s ratio for in-plane deformations and a positive Poisson’s ratio for out-of-plane bending. Second, a cellular metamaterial is described based on a stacking of individual folded layers, where the folding kinematics are compatible between layers. Additional freedom in the design of the metamaterial can be achieved by varying the fold pattern within each layer.

Inflatable structures offer the potential of compactly stowing lightweight structures,\ud which assume a fully deployed state in space. An important category of space inflatables\ud are cylindrical booms, which may form the structural members of trusses or the support\ud structure for solar sails. Two critical and interdependent aspects of designing inflatable\ud cylindrical booms for space applications are i) packaging methods that enable compact\ud stowage and ensure reliable deployment, and ii) rigidization techniques that provide\ud long-term structural ridigity after deployment. The vast literature in these two fields\ud is summarized to establish the state of the art

Thin cylindrical shell structures can show interesting bistable behaviour. If made unstressed from isotropic materials they are only stable in the initial configuration, but if made from fibre-reinforced composites they may also have a second, stable configuration. If the layup of the composite is antisymmetric, this alternative stable configuration forms a tight coil; if the layup is symmetric the alternative stable configuration is helical. A simple two-parameter model for these structure is presented that is able to distinguish between these different behaviours.