▎ 摘　　要

Graphene has been shown to be a high-performance microwave-absorbing material with broadband potential. However, simultaneous realization of multiband compatible strong absorption is still a challenge. In this study, graphene rich in edge topological defects is successfully synthesized, and the effect of defect density on electromagnetic parameters has been investigated. Electrons (pi electrons, pi+sigma electrons) located at edge defects alter the loss paths and plasma absorption frequencies of the graphene aerogels. These improvements in electrical properties give the graphene aerogel a more coordinated impedance matching and attenuation capability, allowing it to achieve strong absorption in multiband (S, X, Ku band) simultaneously. In addition, a mechanically tunable multimode absorber can be further realized by incorporating porous polyimide foam. The strong absorption (>99.9%) of a wide range of variable bands (S, C, X, and Ku bands) can be flexibly adjusted by stress cycling of piezo resistive foam. In addition, self-cleaning, high temperature resistance, and simple processability are expected to deliver solutions for the communication and Internet of Things engineering. (C) 2022 Elsevier Ltd. All rights reserved.