Parallel 3D projection lithography of massive tunable nanopillars for functional structures

Abstract

As a typical nanostructure, nanopillars enable multiple functional structures. However, fabricating nanopillar arrays of large scale and varying sizes is challenging for conventional manufacturing methods. This paper presents a parallel 3D projection lithography that generates 5041 programmable and extended-focal-depth foci for the 3D projection of massive size- and period-tunable nanopillars. Nanopillar arrays of various sizes can be printed by tuning the intensity or the exposure time of each focus. The high aspect ratios of 11.6 and 18.7 are obtained by serial in situ exposure and z -axis scanning, respectively. Large-scale superhydrophobic surfaces with various periods are printed via multiple interlaced exposures, and a maximum contact angle of 167.4° is obtained. The fabricated dynamic self-assembly nanopillars can be controlled by precisely adjusting the intervals or modifying the developing process. Furthermore, metalenses operating at 532 nm with a maximum diameter of 10 mm are designed and fabricated by stitch-free and 3D-grayscale exposure, and their focusability and focal length are verified. The results have well demonstrated the superiority of our scheme for the simultaneous realization of ultrahigh-throughput, volume-exposure, individually controlled, and high-precision grayscale nanofabrication for functional structures.