Rapid and conformal coating of polymer resins by airbrushing for continuous and high-speed roll-to-roll nanopatterning: parametric quality controls and extended applications

Jae Hyuk Lee,Jaekyu Park,Seungjo Lee,Moon Kyu Kwak,Jong G Ok,Jiyeop Kim,Hongseok Youn,Dong Kyo Oh,Minho Na,Kangeun Yoo,Jeong Dae Kim

doi:10.1186/s40580-017-0105-2

Abstract

We present a facile and scalable coating method based on controlled airbrushing, which is suitable for conformal resin coating in continuous roll-to-roll (R2R) nanoimprint lithography (NIL) process. By controlling the concentration of UV-curable polymeric resin with mixing the volatile solvent and its airbrushing time, the coated resin film thickness can be readily tuned. After R2R NIL using a flexible nanoscale line pattern (nanograting) mold is conducted upon the airbrushed resin film, a large-area uniform nanograting pattern is fabricated with controlled residual layer thickness (RLT) based on the initial film thickness. We investigate the faithful airbrushing condition that can reliably create the uniform thin films as well as various nanopatterns with controlled morphologies. Using more diluted resin and shorter airbrushing time can reduce the RLTs favourably for many applications, yet is apt to induce the nanoscale pores and discontinued lines. We also discuss how to further improve the quality and scalability of resin airbrushing and its potential applications particularly requiring high-speed and conformal coating on highly topographic and flexible surfaces.

Highlights

Roll-to-roll (R2R) nanoimprint lithography (NIL) enables large-area nanopatterning either on a rigid or flexible substrate by the continuous imprinting of the nanoscale pattern upon a polymeric resin film based on the pressurized rolling of a mold-bearing roll [1,2,3,4]
This quick process is well-suited to the continuous and high-speed R2R NIL; we first review that a uniform nanoscale line pattern can be faithfully fabricated by conducting R2R NIL with a flexible nanograting mold onto the airbrushed resin films based on our previous work [12]
We systematically investigate the parametric effects of the airbrushing process on the resulting nanopattern quality in our experimental space; reducing resin concentration and airbrushing time can lead to thinner residual layer thickness (RLT) usually favorable in most applications, yet is prone to cause the nanoscale pores and discontinued lines due to solvent evaporation and/or insufficient resin

Summary

Introduction

Roll-to-roll (R2R) nanoimprint lithography (NIL) enables large-area nanopatterning either on a rigid or flexible substrate by the continuous imprinting of the nanoscale pattern upon a polymeric resin film based on the pressurized rolling of a mold-bearing roll [1,2,3,4]. 1 Background Roll-to-roll (R2R) nanoimprint lithography (NIL) enables large-area nanopatterning either on a rigid or flexible substrate by the continuous imprinting of the nanoscale pattern upon a polymeric resin film based on the pressurized rolling of a mold-bearing roll [1,2,3,4].

Results

Conclusion