Figure 2

Schematic of the fabrication process and the fabricated flexible MS hologram. (a) A silicon substrate is initially coated with an Omnicoat layer and a thick SU-8 film by spin-coating. (b) A gold film is evaporated onto the SU-8 film as a reflective backplane. After that, a spacing layer of SU-8 is then spun onto the gold film. Finally, a second gold film is deposited on the SU-8 film. (c) A resist layer of SU-8 is spun onto the final gold layer for the standard electron beam lithography process. Nanorods are defined after the development process and then used as the etching mask. (d) Gold nanorods on the top of the sample are then obtained after a reactive ion etch. The Omnicoat layer is then dissolved to leave a free-floating flexible hologram. (e) An SEM image of a typical area of the nanorod MS taken after lift-off. It was observed that there were no discernible visual differences between the SEM images of the sample before, and after lift-off (see Supplementary Fig. S1).