High-performance wearable bimetallic nanowire-assisted composite foams for efficient electromagnetic interference shielding, infrared stealth, and piezoresistive sensing

With the accelerated development of modern detection and communication technology, the multifunctional wearable materials with excellent electromagnetic interference (EMI) shielding, infrared stealth, and human monitoring for improving military combat capability have received extensive attention. In this work, the lightweight melamine foam (MF)@silver nanowires (AgNWs)-iron nanowires (FeNWs) (AgFe-MF) was fabricated by a vacuum-assisted dip-coating method. Due to the porous structure and synergistic electrical and magnetic losses, this lightweight (0.115 g/cm³) composite foam with an ultra-low filler content (0.62 vol.%) exhibited an ideal EMI shielding efficiency of 38.4 dB. On the other hand, the AgFe-MF realized a powerful multi-functional integration. The surface saturation temperature of the AgFe-MF reached 94.2 °C under a low applied voltage of 1.8 V and remained extremely fast heating and cooling response and terrific working stability, resulting in excellent infrared stealth and camouflage effects. Furthermore, taking virtues of the elastic porous conductive architecture, the AgFe-MF was utilized as a piezoresistive sensor exhibiting board compressive interval of 0–1.62 kPa (50% strain) with a good sensitivity of 0.57 kPa⁻¹. This work will provide new ideas and insights for developing multifunctional wearable devices in the fields of EMI shielding, thermal management, and piezoresistive sensing.