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 similar to 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.