Prof. Anders Kristensen – DTU Nanotech – Technical University of Denmark, Kongens Lyngby
Hosted by: Prof Clivia M. Sotomayor Torres – Phononic and Photonic Nanostructures Group Leader at ICN2
Short Abstract: We describe plasmonic colors based on the concept of localized surface plasmon resonances (LSPR) [1] for decoration of high volume manufactured plastic products [2,3]. Color printing on nanoimprinted plasmonic metasurfaces is achieved by laser post-writing, for flexible decoration of high volume manufactured plastic products. Laser pulses induce transient local heat generation that leads to melting and reshaping of the imprinted nanostructures.
Different surface morphologies that support different plasmonic resonances, and thereby different color appearances, are created by control of the laser pulse energy density. All primary colors can be printed, with a speed of 1 ns per pixel, resolution up to 127,000 dots per inch (DPI) and power consumption down to 0.3 nJ per pixel. A palette of bright and angle-insensitive colors, spanning the entire visible spectrum, is realized by utilizing the hybridization between LSPR modes in aluminium nano-disks, and nano-holes. Research grade, clean-room fabricated plasmonic metasurfaces are transferred to industrial production of plastic consumer products. Plastic components are embossed or injection moulded with a nano-textured surface, comprising an array of nano-scale pillars. The master-original for the square-centimeter nano-texture is realized by means fast e-beam writing [3]. The nano-disk/nano-hole plasmonic metasurface is formed when a thin film of aluminium is deposited on top of the nanopillar array. The nanotextured plasmonic metasurface is covered with a transparent protective coating, which can withstand the daily life handling.