Taiwan Rhinoceros Beetle-Inspired Impact-Resistant Structures as Recoverable Antireflection Coatings

Antireflective structures have been widely used to suppress the light reflection occurring on optical lenses, optical devices, and photovoltaic cells. Nevertheless, most of the structures are highly susceptible to mechanical damage, which significantly diminishes their antireflection performance. Bioinspired by the impact-resistant structures found on the Taiwan rhinoceros beetle forewings, shape memory polymer-based sandwich structures are engineered to serve as an antireflection coating. These sandwich structures, templated from self-assembled monolayer silica colloidal crystals, establish a refractive index transition at the air/substrate interface and hence exhibit broadband antireflective characteristics. Moreover, the presence of porous structures facilitates the dissipation of impact energies to protect the substrate underneath. Once the structures are damaged, the stimuli-responsive structures can even recover their original configurations under ambient conditions. Furthermore, the dependence of the structural geometry of the sandwich structure on the antireflective functionality and impact resistance is systematically studied in this research.