Multifunctional sponges with flexible motion sensing and outstanding thermal insulation for superior electromagnetic interference shielding

Abstract Although electrically conductive polymer composites (ECPCs) are promising in the application of electromagnetic interference (EMI) shielding, how to endow the ECPCs multifunctionality is still a huge challenge. In this work, the novel polyurethane@polydopamine@silver nanoparticles (PU@PDA@Ag) sponges with excellent compressibility, flexible motion sensing, outstanding thermal insulation and superior EMI shielding properties were successfully fabricated by a facile bio-response method, which could be obtained by following two steps: (i) PDA was decorated on the surface of PU sponges by dopamine self-polymerization. (ii) Ag nanoparticles were in-situ grown on the surface of PU sponges by electroless plating. PU@PDA@Ag sponge had the maximum EMI shielding effectiveness (SE) of 84 dB, and the corresponding specific SE and absolute SE were 2625 dB cm3 g−1 and 5250 dB cm2 g−1, much higher than those of other shielding foams/sponges. Meanwhile, PU@PDA@Ag sponge possessed low thermal conductivity (52.72 mW/mK), excellent compression resilience and piezoresistive properties.