Nanopattern Fabrication of Gold on Hydrogels and Application to Tunable Photonic Crystal

Pattern fabrication was performed by transcribing Au nano-dots from Si to the hydrogel surface. The nano-dots exhibited excellent adhesion despite extensive hydrogel expansion and contraction. Au nano-dots on a hydrogel can produce iridescent color, and its spectral response can be finely modulated by controlling the nano-dot spacing. This is a novel tunable photonic crystal made from soft and wet matter.