Electromagnetic (EM) signals lead to electromagnetic emission and interference in the communicating apparatus, which is considered a significant concern in the advanced electronic and telecommunication industries.
To addres these issues, a variety of lightweight materials with electromagnetic interference (EMI) shielding properties have been developed to meet the requirements in the current industries. In addition to traditional copper, carbon materials (carbon nanotubes, graphene, and carbon filers) that have delocalized π electronic networks have drawn significant attention in the scientific communities because the unique advantages in electrically conductive carbon are ideal to allow for achieving the EMI shielding materials with exclusive characteristics.
In this new work, a research team in China proposes novel sandwich structures for manipulating the EM wave transport, which holds unique EMI shielding features of frequency selectivity. By employing electrical and magnetic loss spacers, the resultant sandwich structures are endowed with tunable EMI shielding performance, showing substantial improvements in overall shielding effectiveness along with pronounced shielding peak shift.
"Compared to the conventional uniform bulk and thin-film shielding materials, the sandwich structures were able to present unique frequency selectivity owing to employment of the resonance features," the authors conclude their report. "Further improvements could be achieved via tuning spacers with either electrical loss or magnetic loss properties, which highlight an exclusive platform for designing advanced EMI shielding materials."