Macro-Micro dual wrinkled silver coating enhances stretchable electromagnetic interference shielding and multi-source heating of wearable fabrics

Developing stretchable electromagnetic interference (EMI) shielding wearable fabrics is crucial in light of the increasing electromagnetic pollution. However, achieving satisfactory stretchable shielding ability is challenging due to the significant difference in modulus between the elastic matrix and rigid conductive network. In this study, a dual wrinkled conductive network with macro-wrinkles on the surface of fabric and micro-wrinkles on the surface nanofiber was constructed by in situ anchoring silver coating onto a pre-stretched thermoplastic polyurethane (TPU) electrospinning fabric. The unique geometric dual-wrinkled structure not only enhances the EMI shielding performance from 57.9 dB to 77.8 dB by reinforcing multiple reflecting/scattering. More importantly, it can protect the conductive network from damage during stretching, achieving stretchable EMI shielding performance with maintaining effective shielding of 36 dB under 100 % tensile deformation. Notably, the EMI shielding performance can be restored to the initial level after strain recovery and still holds over 65 dB even after cyclic stretching for 500 times. Additionally, the dual-wrinkled structure imparts stretchable Joule heating and photothermal conversion abilities to the fabric enabling controllable personal thermal management. With its excellent hydrophobicity, gas permeability, and mechanical stretchability, the dual-wrinkled EMI shielding fabric holds significant prospects for the next generation of wearable electronics.