In this presentation we will review our recent activity related to the dynamic reconfiguration of periodic structures and their application. Different reconfigurable periodic 'meta' transmission lines, reconfigurable uniform and a-periodic metasurfaces, will be discussed together with their applications. The proposed concepts are implemented at various frequencies from microwave to terahertz, using different technologies including semiconductors diodes, metal MicroElectroMechanical systems ( metalMEMS), Graphene, and dielectric electro- active polymers (DEAP).