Nano-Organic r-GO-Hybrid Microwave Absorber for Electromagnetic–Thermal–Mechanical Coupled Response and Self-Adaptive Electromagnetic Devices

Elastic electromagnetic-attenuation materials attract great attention for their extensive use both in civil communication and military stealth. Nevertheless, their applications as intelligent materials remain less developed due to insufficient understanding of constructing highly efficient stimulus-response structures. Herein, reduced-graphene-oxide-hybridized polymeric absorbers (GPAs) are prototyped to enable multi-field coupled responses based on electromagnetic (EM) attenuation and smart deformation. A nano-organic hybrid structure is stabilized via intermolecular interactions between rGO and conjugated liquid crystal molecules. It is found that the dielectric polarization in the hybrid structure dominates the electromagnetic attenuation, converting EM energy into thermal energy and inducing mechanical deformation. The GPA incorporating 0.25 wt.% rGO exhibits an average attenuation constant 5.7 times higher than that of the pure polymeric absorber. Under open-space microwave irradiation, the optimal response time of the GPAs is reduced by 85% to ≈10 s. Based on the electromagnetic-thermal-mechanical coupled response of the GPAs, intelligent EM devices including a reconfigurable frequency selective surface and customized microwave-absorbing devices are conceived, achieving frequency transformation over 2.4 GHz and customized radar reflection intensity. This study bridges the gap from elastic material to EM energy dissipative structure and will furnish novel insights for developing intelligent electromagnetic devices.