Conductive Wood for High-Performance Structural Electromagnetic Interference Shielding

Electric conductors are ubiquitously used for electromagnetic shielding, flexible electronics, and energy storage, with metals and carbon-based compounds as traditional choices for these applications. Here, we develop a conductive wood as a new type of structural electromagnetic interference (EMI) shielding material with combined load-bearing function via delignification and subsequent in situ chemical vapor deposition of polypyrrole (PPy) inside the wood channels. The centimeter-long wood channels are well coated by a layer of interconnected PPy, which provides a high electrical conductivity of 39 S m-1. Our results demonstrate that 3.5 cm thick conductive wood displays an EMI shielding effectiveness of ∼58 dB. Moreover, the conductive wood inherits the advanced mechanical strength of natural wood via the carbonization-free process, as the compressive and tensile strengths of the conductive wood are about 3- and 28.7-times higher than those of conventional carbonized wood materials, respectively. This study may pave the way for structural EMI shielding applications using scalable, renewable, and cost-effective biomaterials. Its remarkable advantages, including uniform electrical conductivity, outstanding compressive strength, a controllable material thickness of up to several centimeters, as well as its lightweight and sustainability, ensure strong potential for applications in next-generation structural materials.