Ultrathin, flexible, and high-strength Ni/Cu/metallic glass/Cu/Ni composite with alternate magneto-electric structures for electromagnetic shielding

Electromagnetic interference (EMI) shielding materials with ultrathin, flexible, superior mechanical and thermal management properties are highly desirable for smart and wearable electronics. Here, ultrathin and flexible Ni/Cu/metallic glass/Cu/Ni (Ni/Cu/MG) multilayer composite with alternate magnetic and electrical structures was designed via facial electroless plating of Cu and Ni on an Fe-based metallic glass. The resultant 0.02 mm-thick Ni/Cu/MG composite displays a superior EMI shielding effectiveness (EMI SE) of 35 dB and a great EMI SE/t of 1750 dB/mm, which is greater than those of composites with monotonous multilayer or homogeneous structures. The improved EMI SE originates from the massive ohmic losses, the enhanced internal reflection/absorption, and the abundant interfacial polarization loss. Particularly, Ni/Cu/MG exhibits a high tensile strength of up to 1.2 GPa and outstanding mechanical stability, enabling the EMI SE remains unchanged after 10,000 times of bending. Moreover, Ni/Cu/MG has excellent Joule heating characteristics and thermal stability, which is very suitable for heating components of wearable hyperthermia devices.