Lightweight nano-metallized wood: Toward high-performance electromagnetic interference shielding with multifunctional attributes

The proliferation of electronic devices has heightened the demand for effective electromagnetic interference (EMI) shielding materials with lightweight and sustainable properties. This study presents the development of lightweight, nano-metallized wood with superior EMI shielding effectiveness, water repellency, and infrared shielding capabilities. Balsa wood was subjected to magnetron sputtering to deposit ultra-thin Cu and Ni metal films, achieving a total thickness of 100 nm. The Cu-Wood-Cu (Cu-W-Cu) structured material demonstrated the highest EMI shielding performance, with an average shielding effectiveness of 31.73 dB, surpassing commercial requirements. The material’s hydrophobicity was significantly enhanced, with water contact angles reaching up to 103.2°, attributed to the increased surface roughness. Infrared shielding performance was also notable, with the Cu-W-Cu material reflecting a majority of incident infrared radiation, reducing the surface temperature by 36.9 °C compared to the heating source. The study elucidates the material’s potential in practical EMI shielding applications, showcasing its effectiveness in blocking electromagnetic signals from a Tesla coil and mobile phone signals. The findings underscore the promise of these sustainable, lightweight wood-based materials in addressing multifaceted protection needs, including EMI shielding, water resistance, and thermal management.