Large-area nanopatterning for plasmonics and optics via nanocoining and roll-to-roll lithography

Micro- and nanoscale patterns enable a diverse technology set, from displays and light-trapping films to plasmonic metamaterials. Despite their transformative potential, conventional nanofabrication methods are prohibitively slow and expensive for large-area applications like solar panels, television screens, or window coatings. Here, we will present truly large-area nanopatterning of hundreds of square feet of polymer or metalized films using a combination of “nanocoining” and roll-to-roll (R2R) nanoimprint lithography (NIL). Smart Material Solutions, LLC’s (SMS’s) nanocoining process uses a diamond-turning lathe and a nanopatterned diamond die to seamlessly indent features into the outer diameter of the mold. The die is mounted on an ultrasonic actuator to register 45,000 indents per second on a rotating metal drum. Precise control of the drum rotation speed, crossfeed, and the actuator frequency enables side-by-side tiling of the indented features. Our R2R partners then mount the seamless mold on their R2R lines to rapidly create hundreds of feet of patterned polymer film. The nanocoining process is also used to make a seamless cylindrical photomask. These can be used to create a residualfree etch mask on a non-transparent substrate, like metalized films, via R2R lithography. This mask enables R2R wet etching of metalized films to create plasmonic metamaterials. In this talk, SMS will discuss the latest progress in seamless, residual-free etch masks for tuned IR plasmonic absorbers. We’ll also discuss how we used these methods to create hundreds of linear feet of light trapping films for flexible solar panels with performance enhancements of 5-20%.