Microfluidically tunable paper-based inkjet-printed metamaterial absorber

This paper describes a tunable metamaterial (MM) absorber that incorporates novel microfluidic channels and is realized using inkjet printing on a photo-paper substrate. The fabricated sample demonstrated frequency-switching capability owing to distilled water flowing in the microfluidic channels. In addition, the resonant frequency was changed from 4.42 to 3.97 GHz when the empty channels were filled with de-ionized water. An analysis of the results suggests that microfluidic technology is a simpler and more effective way to achieve tuning functionality. The proposed structure is the first microfluidic absorber based on a photo-paper substrate.