A modular structure may comprise multiple mechanical linkages. The structure may undergo two-dimensional or three-dimensional shape transformations, such as bending, twisting, shearing, uniform scaling, and anisotropic scaling. These shape transformations may be actuated by applying force to one or more specific locations in the structure. Each of the linkages in the modular structure may comprise a four-bar linkage. The exact shape transformation that the structure undergoes may be determined by the type and location of the linkages in the structure.