Temperature‐Induced Impedance Gradient Polyimide Nonwoven Fabric for Intelligently Adjustable Broadband Microwave Absorption

ABSTRACT Designing and fabricating adjustable microwave absorption (MA) materials is crucial for advanced intelligent camouflage. Hence, a temperature induced polyimide/graphene/vanadium dioxide (PI/GN/VO 2 , PGV) nonwoven fabric is fabricated for intelligently adjustable broadband MA. The incorporation of graphene promotes the formation of a critical conductive network between fibers. The semiconductor‐to‐metal phase transition of VO 2 combined with a critical conductive graphene network promotes the formation of a microwave dissipation network. One‐side thermal stimulation induces impedance gradient under synergistic effect of intrinsic property of graphene and phase transition of VO 2 , bringing broadband microwave absorption performance ( RL min = −21.19, EAB = 7.84 GHz). Hence, a superior intelligently adjustment ( ΔEAB = 5.97 GHz) be achieved between the non‐stealth state (high electromagnetic reflection) at low stimulation temperature and stealth state (high electromagnetic absorption) at high stimulation temperature. Such excellent adjustable broadband microwave absorption performance makes it promising to become an intelligent material to be applied in the fields of military camouflage for high‐low altitude transition across multiple scenes.