News and Reviews (February 2016)

Bio-Inspired Skin-Like Displays

Image: D. Franklin et al., Nature Communications 6, 7337 (2015)

(Debashis Chanda) The range of colors and hues in the natural world are amazing, but perhaps even more astonishing is the ability of certain species to actively mimic them. Though the specific mechanisms are as varied as the species, each has a set of color producing cells which can span the visible spectrum.  The key aspect of color displays in nature is generation of color on a thin, flexible and conformally mapped surface whereas our manmade state-of-the art displays still remained rigid, brittle and bulky in nature.

It’s with mimicking nature in mind that we at Nano-Optics group, University of Central Florida developed a flexible reflective plasmonic display in which each pixel is actively tuned across the visible spectrum using liquid crystals (LC). The implementation of dynamic pixels reduces the need for multiple colored subpixels, thereby eliminating layered processing steps, increasing resolution, and allowing unrivaled color control.  Using nanoimprint lithography (NIL) to produce the plasmonic structures over large areas, we can bypass expensive and tedious electron-beam (EBL) or deep-UV lithography techniques used in fabricating many previously reported plasmonic devices. This in combination with ultrafast direct laser writing (DLW) using Nanoscribe’s laser lithography system, we can incorporate multiple features at varying size scales into our master patterns.  A single device master can include arbitrarily pixelated plasmonic surfaces, microscopic LC cell spacers, and nanoscale LC alignment gratings.  One such master can produce 100’s of polymeric imprinting stamps, and one such stamp can produce 1000’s of imprints without any noticeable pattern degradation. NIL has also been translated to roll-to-roll processing which shows the entire fabrication process can be scaled to factory norms. 

Now we wish to bring these results from the lab to the world through ‘e-skin displays Inc.’. The journey will continue, as we attempt to fully realize nature-like color generation.  

This article was provided by our customer NSTC/CREOL, UCF, Dr. Debashis Chanda

[1] Polarization-independent actively tunable colour generation on imprinted plasmonic surfaces
Franklin, D., Chen, Y., Vazquez-Guardado, A., Modak, S., Boroumand, J., Xu, D., Wu, S.-T., and Chanda, D.
Nature Communications 6,7337,DOI:10.1038/ncomms8337