Metafoils with extreme mechano-optical properties for solar radiation isolation

Metal-polymer interfaces are used widely in satellite missions as they show extreme thermal isolation and elevated interface strength. In space, robust interfaces between nanomaterials are essential as thermal gradients and strain may result in device failure. Here we show flexible metafoils with ultrastable plasmon resonances allowing transmission of visible radiation while reflect the unwanted infrared responsible for device heating. Electromagnetic and nanomechanical simulations confirm our experimental findings showing extreme robustness with strains up to $\sim\mathbf{20}\%$ , equivalent to thermal expansion in temperatures of $> \mathbf{10}^{\mathbf{4}}\ \mathbf{K}$ . Such space solar isolators can be used along with photovoltaic panels allowing optimum interplay with visible light for efficient charging. Resilient ultrathin metasurfaces are highly desirable for mechano-optical applications in harsh environments ensuring small footprint and lightweight devices.