Multifunctional cellular metals (or other materials) for structural applications that are capable of recovering their original (undeformed) shape and thickness after impact or crushing (i.e., self-healing). Alternatively, they may normally be stored or used in their compressed (i.e., crushed) state and deployed when needed to act as energy absorbing structure or packaging (i.e., deployable energy absorber). Additionally, the multifunctional structures may act as an actuator, capable of providing localized or distributed force and displacement, and related methods of using and manufacturing the same. These active cellular metals (or other materials) are composites consisting of conventional metal/alloy truss structures (or other material structures) in combination with shape memory metal/alloy components (or other material components) and offer high specific strength and stiffness, but which are also deployable energy absorbers or self-healing smart structures.