Roll-to-roll fabrication of plasmonic color surfaces

What is it about?

The paper is about printing with ink free colors. It works due a coupling of the electron clouds in nanoscale metallic structures and the light waves from visible light. This sort of interaction of light with matter is called a plasmonic interaction. In this work, we managed to fabricate those metallic nanostructures that are responsible for the plasmonic effect by employing an industrial “potato-chip bag” metallization method. We demonstrate a roadmap for this technology to go from wafer scale surface areas to much larger areas on a polymer foil. One of the issues that were solved in this work is the lifting of the requirement to have a very precise metallization thickness, which was employed in the former lab-scale demonstrations of the plasmonic effect. This very thin and precise metal thickness was required to produce well defined nanoscale metallic discs that would sit on the asperities of polymer nano pillars and not physically touch the metal layer between the pillars. In this work we discovered how to achieve the plasmonic effect with a continuous metal layer, which only relies on tiny nanoscale gaps at some points at the circumferences of the pillars. In this way, the plasmonic color effects become much more robust in an industrial production scenario.

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Why is it important?

This finding can pave the way for plasmonic meta-surfaces to be implemented in a broader range of applications such as printing, memory, surface enhanced Raman scattering (SERS), biosensors, flexible displays, photovoltaics, security, and product branding.

Perspectives