Study of Electromagnetic Interference Shielding Effectiveness of Conductive Polymer Composites

A new type of pollution known as electromagnetic interference (EMI) is one of the major problems in today’s wireless world due to developments and advances in science and technology. This EMI not only interferes with the normal operation of electronic equipment, but also adversely affects human health. Conductive Polymer Composite (CPC) shields have taken an important place for shielding purposes due to their advantages such as light weight, low cost, flexibility, chemical resistance and corrosion resistance. The Shielding Effectiveness (SE) of composites against EM radiation strongly depends on the manufacturing technique used, conductivity, thickness, and dielectric properties of the composite. To this end, various composites were studied using insulating polymer matrices combined with different types of conductive fillers such as graphite (Gr), carbon nanotubes (CNT) and nanometal particles and various types of biochar from biomass such as sugarcane bagasse, bamboo and wood chips. Shields can be manufactured using compression molding techniques for rigid shields and solvent casting for flexible sheets. Impedance analyzers are used to measure the dielectric properties and vector network analyzers are used to measure the S-parameters of different shields manufactured in different high frequency ranges. The far-field EMI shielding using the obtained dielectric properties and S-parameters can be calculated.