Highly tunable rGO composites for EMI shielding inks: A tailored approach to modulate broadband EMI shielding

In this study, we demonstrate the ability to design tunable electromagnetic interference (EMI) shielding by controlling the dominant shielding mechanism, whether it is absorption or reflection, using graphene-based nanocomposites. We synthesized four different composites and their corresponding acrylic- based inks to investigate the impact of additives on the EMI shielding mechanism. We conducted measurements on both liquid and printable structures, and the results were highly promising. The coatings exhibited a maximum shielding efficiency of over 200 dB/mm. To achieve targeted shielding for specific frequency bands (here 10 GHz), we tested metastructures printed with the synthesized inks for their shielding effectiveness. Remarkably, these structures, when screen printed on flexible and transparent polyvinyl chloride substrate, achieved over 90% microwave attenuation. Overall, this research highlights the potential of printable EMI shielding solutions, enabled by graphene-based nanocomposites, to effectively address microwave interference issues in a wide range of electronic devices and defence applications.