Multiscale Design of Dual-Gradient Metamaterials Using Gel-Mediated 3D-Printed Graphene Aerogels for Broadband Electromagnetic Absorption. - Lv, Xiong; Li, Changfeng; Wang, Ge; Estevez, Diana; Yang, Junjie; Chen, Qian; Qin, Faxiang (Nano-Micro Letters, 2026)