MECHANICALLY-TUNABLE METAMATERIAL FOR MULTI-BAND ABSORPTION

Abstract

In this work, we proposed a mechanically-tunable metamaterial perfect absorber by exploiting a pasted nano silver ink on flexible polyimide substrate. At flat configuration, the proposed structure is acted as a single band metamaterial absorber in which a resonance peak induced at 3.7 GHz with an absorptivity of 99.9%. Under mechanical deformation, our structure is bent and wrapped on to a cylindrical surface. At this configuration, the high absorption feature at 3.7 GHz is maintained well while there are new peaks appear at higher frequencies. When the bending radius changes from 400 mm to 200 mm, the proposed structure can be switched between single-band and triple-band models. In addition, the designed MPA exhibits polarization-insensitive and stable with respect to the oblique incidence up to 50 degrees. Furthermore, for both flat and curved states, the absorption mechanism is explained by the perfect impedance matching and the surface current distributions. Finally, the design of the MPA is scaled down for operation in the THz region, while still demonstrating effective tunability between single-band and dual-band absorption modes through mechanical deformation.