Highly Robust, Flexible, and Large-Scale 3D-Metallized Sponge for High-Performance Electromagnetic Interference Shielding

Electromagnetic interference (EMI) is a type of pollution that is caused by the ubiquitous usage of electronic communication in general, and military radar equipment in particular. Even though this is a common problem for a long time, the fabrication of large-area, flexible, and robust EMI shielding materials is still a challenge today. In this work, the 3D meshing strategy is simulated for most efficient utilization of metallic silver for X-band EMI shielding, and propose a roll-to-roll (R2R) process to fabricate robust, flexible, and large-scale EMI shielding sponge, silver nanowires/polyvinyl butyral (PVB) melamine sponge (AgPMS). Typically, 0.5 cm thick sponge has about 60 dB total EMI shielding efficiency (SE) in the microwave band, which is higher than for commercial EMI shielding sponges (about 45 dB) of the same thickness. AgPMS shows unchanged electrical properties after 1000 compression and bending cycles. Moreover, a AgPMS garment is made to demonstrate the excellent EMI shielding performance and remarkable flexibility of this material. Those properties suggest that AgPMS can be readily applied in challenging environments like hospitals, military installations, remote communication centers, and for any devices with curved surfaces.