4D printed thermally tunable metasurface with continuous carbon fibre

Multifunctional metamaterials with unique electromagnetic and mechanical properties are highly desired in many fields, including space exploration and satellite communication, where broad tunability of the working frequency and controllable mechanical deformation properties are usually necessary. In this study, we propose a metasurface exhibiting simultaneous electromagnetic frequency selection capability and isotropic negative/positive/near-zero thermal expansion. The metasurface is designed based on chiral structures and is fabricated via 4D printing of continuous fibre composites. Both the effective thermal expansion coefficient and electromagnetic transmission band were investigated in different structural parameters based on theoretical calculation, finite element analysis simulations and experiments. The measured results were in good agreement with the theoretical data which reveal the influence law of structural parameters on thermal deformation and electromagnetic frequency control. Thus, the electromagnetic functionality of the metasurface can be thermally controlled and is expected to be useful in extreme situations where the coupling of multiphysical fields is required.