Ultrabroadband Low‐Frequency Microwave Absorption in Multiscale Aerogel‐Metamaterial Hybrids
Jingpeng Lin, Lichen Wang, Weiqin Chu, Huijuan Yu, Zhanpeng Chen, Mingji Chen, Weili Song, Xuan Gu, Jing Liu, Wu Na, Zhihui Zeng
Abstract
ABSTRACT The increasing demand for lightweight electromagnetic wave (EMW) absorbing monoliths, particularly those capable of absorbing both low‐frequency and broadband EMWs, presents a significant challenge. While dielectric nanostructured aerogels have demonstrated high potential and advancements, a gap remains in the development of aerogel‐based EMW absorbers to achieve effective low‐frequency and broadband absorption. Here, we present a multiscale engineering strategy for fabricating aerogel‐metamaterial hybrids, addressing key challenges such as broad bandwidth, low‐frequency absorption, and high load‐bearing capacity. The proposed absorber consists of a simulation‐assisted additive‐manufactured thin‐walled enclosure embedded with graphene/nanocellulose aerogels, which feature an effective conductive network and abundant heterogeneous interfaces. This multiscale design enables exceptional EMW absorption across the entire 2–18 GHz band, achieving 100% bandwidth coverage, with stable performance under wide oblique incidence (up to 60°) and polarization (both transverse electric and transverse magnetic). Furthermore, the absorber exhibits a low areal density of 2.714 kg m −2 and can withstand at least 95 kg of out‐of‐plane load. These advancements highlight the potential for developing lightweight, novel EMW‐absorbing aerogel metamaterials for low‐frequency, ultrabroadband electromagnetic compatibility and aerospace applications.