Flexible and easy-to-tune broadband electromagnetic wave absorber based on carbon resistive film sandwiched by silicon rubber/multi-walled carbon nanotube composites

A type of flexible, broadband electromagnetic microwave absorber is designed, simulated, manufactured and characterized. The multilayer-structured absorber is composed of a screen-printed carbon-based resistive film sandwiched between two layers of silicon rubber/multi-walled carbon nanotube composites and in turn backed by aluminum foil. The theoretical analysis based on the equivalent circuit model and the electromagnetic simulations is instructive for the design of the absorbers with the desired operation frequency by simply tuning the thickness of the dielectric substrates and the utilization of the one carbon film. The absorber indicates a broadband absorption, with a 90% absorption bandwidth of 13.5 GHz, and the thickness of the dielectric substrate of 5 mm. The fabricated absorber also shows a flexibility that it can be bent, rolled and twisted without breakdown of the structure and degradation of the absorption performance.