The unique three-dimensional (3D) deformations caused by nano-kirigami have enabled a new degree of freedom for reconfigurable optics. Here we demonstrate a facile nano-kirigami method that can create 3D deformed structures, which can flexibly manipulate optical properties by thermally actuated micro-/nanoscale deformations. By connecting four pairs of thermal actuators to the four sides of a gradient metasurface, large-angle beam steering (~90°) can be achieved through adjusting the temperature of the actuators. The amplitude of circular dichroism can be adjusted by thermally actuating micro-/nanoscale deformations. The 2D-to-3D transformation of curved arm structure on metallic substrate results in enhanced structural absorption, inducing an almost perfect absorption at specific wavelengths. Curved asymmetric structures can also be created by thermally actuated micro-/nanoscale deformations, which provides a novel method for cross-polarized light conversion. The proposed design with thermally actuated micro-/nanoscale deformations provides a new methodology to explore versatile reconfigurable functionalities.

Active plasmonic nanostructures have attracted tremendous interest in nanophotonics and metamaterials owing to the dynamically switchable capabilities of plasmonic resonances. In this study, tunable hybrid plasmon resonances (HPR) of sodium metasurfaces through heat‐initiated structural transformation is experimentally demonstrated. A HPR is formed by coupling surface plasmon polaritons (SPP) and gap plasmon resonances (GPR), whose resonant wavelengths are highly sensitive to gaseous nanogaps. By carefully manipulating the thermo‐assisted spin‐coating process and post‐thermal treatment, tuning of the HPR is achieved because of the phase transition between the antidome and nanodome structural profiles of liquid sodium inside the patterned fused silica substrates. Furthermore, the figure of merit of the heat initiated variable structure‐spectrum is demonstrated that is highly dependent on the size of the substrate patterns, based on which temperature‐sensitive plasmonic color and “invisible ink” of sodium metasurfaces are demonstrated. These findings can lead to new solutions for manipulating low‐cost and high‐performance active plasmonic devices.