Tensile Stress-Gated Electromagnetic Interference Shielding Fabrics with Real-Time Adjustable Shielding Efficiency

Abstract

Traditional electromagnetic interference (EMI) shielding films generally have constant shielding efficiencies that cannot respond to the real-time changing shielding requirements of smart wearable electronics. Here, we report a stress-gated EMI shielding fabric with a high elastic strain of 470% that exhibits variable shielding performance by stretching the fabric to different deformations. The fabric is fabricated through electroless plating Cu nanoparticles on the electrospun polyurethane nanofiber films, which can change from conducting to insulating when the stretch deformation reaches 50% and then back to conducting as the stress is released. The deformation causes repeated separation and contact of Cu nanoparticles on the surfaces of polyurethane nanofibers, resulting in a reversible transition between conducting and insulating. The fabric with tensile stress-gated conductivity can capture and weaken electromagnetic waves through absorption, reflection, and scattering, which shows real-time changing EMI shielding efficiencies from 0 to 52.31 dB. More importantly, the developed method of electroless plating for the deposition of continuous metal nanoparticles on elastic polyurethane nanofibers is new and scalable, which shows broad application prospects in smart EMI shielding fields.